A120 BRAINTREE TO A12
Essex County Council
TECHNICAL APPRAISAL REPORT
B3553T41-JAC-HGN-00-REP-C-0002 | P01
11/1/17
TECHNIC AL A PPR AISAL R EPORT Ess ex C ounty Council A120 Braintree to A12 Technical Appraisal Report
Contents Contents ...... 3 1. INTRODUCTION ...... 8 1.1 Document purpose and structure ...... 8 1.2 Scheme Description ...... 9 2. PLANNING BRIEF ...... 10 2.1 Study Area ...... 10 2.2 Justification for the scheme ...... 11 2.3 Scheme Objectives ...... 12 2.4 Previous Work and Studies ...... 12 3. EXISTING CONDITIONS ...... 14 3.1 Description of Locality ...... 14 3.2 Existing Highway Network ...... 14 3.3 Traffic ...... 16 3.4 Existing Safety Conditions ...... 17 3.5 Topography, Land Use, Property Industry ...... 26 3.6 Climate...... 27 3.7 Drainage ...... 27 3.8 Geology ...... 28 3.9 Mining ...... 28 3.10 Public Utilities ...... 29 3.11 Technology ...... 29 3.12 Existing Maintenance including Access ...... 29 3.13 Environmental Status ...... 30 3.14 Environment ...... 32 3.14.1 Air Quality and Carbon Emissions ...... 32 3.14.2 Cultural Heritage ...... 32 3.14.3 Landscape ...... 33 3.14.4 Nature Conservation ...... 35 3.14.5 Geology and Soils ...... 41 3.14.6 Materials ...... 42 3.14.8 Noise and Vibration ...... 45 3.14.9 People and Communities ...... 45 3.14.10 Road Drainage and the Water Environment ...... 46 3.15 Accessibility ...... 50 3.15.1 Severance ...... 50 3.15.2 Public Transport Accessibility ...... 51 3.15.3 Non-Motorised User Safety ...... 51 3.16 Integration ...... 52 3.16.1 Role within the Strategic Road Network ...... 52
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3.16.2 International Transport Links ...... 52 3.17 Maintenance and Repair Strategy Statement ...... 53 3.18 Other Relevant Factors ...... 53 4. PLANNING FACTORS ...... 54 4.1 Option Constraints ...... 54 4.2 Planning Policies ...... 54 4.2.1 Local and Regional Planning Policies ...... 54 4.2.2 National Policies ...... 56 4.3 Route to Consent ...... 57 5. DESCRIPTION OF ROUTE OPTIONS ...... 59 5.1 Introduction ...... 59 5.2 Options generation phase (Stage 0) ...... 60 5.3 Initial option assessment (Stage 1) ...... 63 5.4 Design parameters and assumptions ...... 64 5.5 Other schemes ...... 67 5.6 Option 3 ...... 68 5.7 Option 4b ...... 70 5.8 Option 1b ...... 71 5.9 Option 9a ...... 72 5.10 Option 8 ...... 72 5.11 Scheme Costs ...... 73 5.12 Engineering Assessment ...... 74 5.12.1 Geometric Provision ...... 74 5.12.2 Geotechnical issues ...... 74 5.12.3 Drainage and surface water runoff ...... 76 5.12.4 Statutory Undertaker’s Plant ...... 76 5.12.5 Existing Structures ...... 77 5.12.6 Proposed Structures ...... 78 5.12.7 Non-Motorised Users ...... 78 5.12.8 Construction assessment ...... 82 5.12.9 Other Engineering Considerations ...... 86 6. TRAFFIC ANALYSIS ...... 87 6.1 Traffic Data and Model ...... 87 6.1.1 Background to modelling ...... 87 6.1.2 Development of the Traffic Model: ...... 87 6.1.3 Traffic Flows ...... 87 6.1.4 Journey times ...... 88 6.1.5 Conclusion ...... 88 7. ECONOMIC ASSESSMENT ...... 89 7.1 Economic Assessment Methodology ...... 89 7.2 Results ...... 89
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7.2.1 Headline results – initial BCR ...... 89 7.2.2 Adjusted BCR calculation ...... 90 7.3 Comparison of options...... 90 7.4 Conclusions on BCR ...... 91 7.5 Business case ...... 91 8. SAFETY ASSESSMENT...... 93 8.1 Impact on Road User - Strategic Safety Action Plan ...... 93 8.2 Impact during Construction and Operation - Construction (Design and Management) Regulations 2015 ...... 98 9. OPERATIONAL ASSESSMENT ...... 102 9.1 Introduction ...... 102 9.2 New A120 and junctions ...... 102 9.2.1 Opening year (2026) daily flows on the new A120 ...... 102 9.2.2 Design year (2041) peak hour flows on the new A120 ...... 103 9.2.3 Weaving between junctions on the new A120 ...... 104 9.2.4 Junctions on the new A120 ...... 105 9.3 Adjacent sections of A12 ...... 105 9.3.1 Design year (2041 peak hour flows on the new A120 ...... 105 9.3.2 Weaving between junctions on the A12 ...... 107 9.4 Local roads ...... 108 9.5 Conclusions ...... 108 10. TECHNOLOGY ASSESSMENT ...... 109 10.1 Options Design Implications for the Utilisation of Technology in terms of: ...... 109 10.1.1 ITS systems - Traffic loops, VMC, CCTV etc...... 109 10.1.2 Communications Network...... 109 11. MAINTENANCE ASSESSMENT ...... 110 11.1 Impact of Operational Regime ...... 110 11.2 Maintenance Strategies ...... 111 12. ENVIRONMENTAL ASSESSMENT ...... 112 12.1 Introduction ...... 112 12.2 Air Quality and Carbon Emissions ...... 112 12.3 Cultural Heritage ...... 112 12.4 Landscape ...... 112 12.5 Nature Conservation ...... 113 12.6 Geology and Soils ...... 114 12.7 Materials ...... 114 12.8 Noise and Vibration ...... 114 12.9 People and Communities ...... 115 12.10 Road Drainage and Water Environment ...... 115 12.11 Overall Conclusions ...... 116 13. ASSESSMENT SUMMARY ...... 117 14. PROGRAMME ...... 128
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15. CONCLUSION OF RECOMMENDATIONS...... 129 15.1 Option(s) for Public Consultation ...... 129 15.2 Preferred Solution ...... 129 16. DETAILED COST ESTIMATE ...... 130
Appendix A. A120 Route Plan Drawings ...... 131 Appendix B. Plan and Profile Drawings ...... 132 Appendix C. Accident Location Plans ...... 133 Appendix D. List of Existing Structures ...... 134 Appendix E. List of Proposed Structures ...... 135
Table of Tables
Table 1: Mapping Project Objectives to Road Investment Strategy Objectives ...... 12 Table 2: Average Journey Times and Speeds in Peak Periods ...... 17 Table 3: Collisions by year and severity (A120) ...... 18 Table 4: Collisions by year and severity (A12 NB – 2010 – 2014) ...... 18 Table 5: Collisions by year and severity (Local roads in study area – 2010 – 2014) ...... 19 Table 6: Collision clusters by SRN Location (by collision severity) ...... 20 Table 7: Collision clusters by Local Road Location (by collision severity) ...... 20 Table 8: Casualties by year and severity - A120 ...... 21 Table 9: Casualties by year and severity (A12 2010 – 2014)...... 21 Table 10: Casualties by year and severity (Local roads in study area 2010 – 2014) ...... 21 Table 11: Casualty Rates, KSI and FWI rates per hundred million vehicle miles by year (2011 – 2013) ...... 22 Table 12: A120 Non-Motorised User Collisions and Casualties (2011 – 2015) ...... 23 Table 13: A120 Collisions by daylight / darkness by year ...... 23 Table 14: A120 Collisions by wet or dry road surface condition by year ...... 23 Table 15: A120 Collisions by Time of Day by Year ...... 24 Table 16: A120 Collisions by Time Period compared with SRN norm ...... 24 Table 17: A120 Scheme Study Area – Vehicles Involved ...... 25 Table 18: Study Area Casualty Analysis (2011 – 2015) ...... 25 Table 19: Contributory Factors - A120 ...... 26 Table 20: Environmental Designations ...... 31 Table 21: Summary of cultural heritage asset values ...... 33 Table 22: Key Visual Receptors ...... 34 Table 23: Habitats and Valuations ...... 37 Table 24: Protected and notable species recorded or potentially present ...... 40 Table 25: Land-won aggregates: reserves and landbanks 2013 ...... 43 Table 26: CD&E recycling facility capacity summary (Essex County Council, 2015) ...... 44 Table 27: Inert landfill capacity summary ...... 44 Table 28: Hazardous waste facilities ...... 44 Table 29: Organic treatment and organic treatment with energy recovery facilities summary ...... 45 Table 30: Value of receptors for flood risk ...... 47 Table 31: Baseline overview of watercourses, ponds and lakes ...... 49 Table 32: Non-Motorised User Collisions and Casualties – A120 (2011 – 2015) ...... 52 Table 33: Route options at end of Stage 0 sifting process ...... 63 Table 34: Route options for detailed assessment ...... 64 Table 35: Options Cost Estimate ...... 73 Table 36: Bradwell Quarry Excavation Timeline ...... 75 Table 37: Crossings of NMU Facilities by Option ...... 79 Table 38: Options Assessment – NMU Severance / Safety and Public Transport Accessibility ...... 81 Table 39: Options Assessment Categories ...... 81
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Table 40: Constructability Assessment Option Preference ...... 86 Table 41: Headline Economic Results (£ millions, 2010 market prices discounted to 2010 base year) ...... 89 Table 42: Adjusted BCR Calculation (all monetary values in £ million, 2010 prices discounted to 2010) ...... 90 Table 43: Road User and Road Worker Option Assessment ...... 97 Table 44: A120 CDM 2015 Summary ...... 98 Table 45: Opening year (2026) AADT flows ...... 102 Table 46: Design year (2041) A120 AM Peak hour flows ...... 103 Table 47: Design year (2041) A120 PM Peak hour flows ...... 103 Table 48: Design year (2041) A12 AM Peak hour flows ...... 106 Table 49: Design year (2041) A12 PM Peak hour flows ...... 106 Table 50: Number of lanes required for weaving on the A12 ...... 107 Table 51: Option 1B Appraisal Summary Table ...... 118 Table 52: Option 3 Appraisal Summary Table...... 120 Table 53: Option 4B Appraisal Summary Table ...... 122 Table 54: Option 8 Appraisal Summary Table...... 124 Table 55: Option 9A Appraisal Summary Table ...... 126 Table 56: Link between pre and post environmental mitigation scoring in EAR and AST ...... 127
Table of Figures
Figure 1: Location of the A120 (Source: Highways England A12/A120 route based strategy, March 2013) ...... 9 Figure 2: Geographic Area of Impact ...... 10 Figure 3: Major Scheme Development Phases ...... 59 Figure 4: Aggregated options for sifting ...... 60 Figure 5: Shortlisted route alignments ...... 62
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1. INTRODUCTION
1.1 Document purpose and structure
This is the Technical Appraisal Report (TAR) for A120 Braintree to A12 improvement scheme. This TAR is the report on the technical aspects of the highway problem and the sustainable alternative solutions. The TAR brings together the traffic, economic, safety and environmental assessments, and is the basis for deciding which option(s) should be included in the Public Consultation. This TAR will:
• Inform the option(s) identified for the scheme route within the framework defined by objectives set down by the Client and scheme objectives and lead into the engagement in Stage 2 Option Selection, and a preferred route, however this report would not validate a preferred route or options.
• Identify and evaluate the scheme routes with regard to the Government’s current economic appraisal, economic assessment and value for money, engineering, safety, effect on the economy, social and environmental factors.
The aim of this document is to present the technical appraisal of the outlined options to be further considered during PCF Stage 2 – options selection.
The various options outlined in this report have been produced in accordance with the Design Manual for Roads and Bridges (DMRB).
Following this introduction, the TAR is structured into a further 15 chapters:
• Planning Brief
• Existing Conditions including Environmental Status
• Planning Factors
• Description of the Route Options
• Traffic Analysis
• Economic Analysis
• Safety Assessment
• Operational Assessment
• Technology Assessment
• Maintenance Assessment
• Environmental Assessment
• Assessment Summary
• Programme
• Conclusions and Recommendations
• Detailed Cost Estimate
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1.2 Scheme Description
The A120 trunk road forms a strategic east-west corridor between the M11 near Stansted Airport to Harwich and Harwich International Port, via the A12 between junction 25 at Marks Tey and junction 29 on the Colchester bypass. This general study area is illustrated in Figure 1 below.
Figure 1: Location of the A120 (Source: Highways England A12/A120 route based strategy, March 2013)
The A120 is part of the Strategic Road Network (SRN) and performs several functions: • At the strategic level the corridor provides access to Stansted Airport and the Haven Ports, in particular Harwich International Port, for the movement of freight and passengers. Furthermore, it forms part of the Trans-European Network carrying international traffic. • At the regional level the corridor provides access to regional centres such as Colchester. • At the local level the corridor provides the only access for many villages and towns along the route to essential services and employment. The A120 has a varied standard along its length, being a high standard dual-carriageway from the M11 to Braintree Town, but with the section between Braintree Town at Marks Farm roundabout and the A12 at Marks Tey being in general a narrow single carriageway alignment. The section of the A120 under specific consideration for this study is from the A131 junction on Braintree Town bypass to junction 25 on the A12 at Marks Tey, from here on referred to as the corridor. The corridor lies within Braintree District for the majority of its length with the eastern end lying in Colchester Borough. It passes through a number of villages including Bradwell, Broad Green and Marks Tey as well as bypassing Coggeshall.
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2. PLANNING BRIEF
2.1 Study Area
The study area has been defined in two ways that are derived from Department for Transport (DfT) guidance. The first is the Geographic Area of Impact (GAI) and the second the Geographical Scope of the Travel Market (GSTM).
The GAI is based on the analysis of the geographical extent of current and future transport problems. This area is illustrated in Figure 2 below.
Figure 2: Geographic Area of Impact
The Geographic Area of Impact effectively defines the area within which options will be generated to solve the transport related problems identified for the corridor.
The Geographical Scope of the Travel Market is based on a very preliminary understanding of the extent of key origins and destinations. Given the strategic nature of the corridor this represents a very broad area that includes: • Within Essex County: this includes the districts of Braintree, Uttlesford, Colchester, Tendring, Harlow and Epping Forest west of the M11, • Outside Essex County but within the East of England region: the A12 corridor through Suffolk to Lowestoft, • Outside of East of England: north of the M25 and all travel to the north and west of England.
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2.2 Justification for the scheme
The socioeconomic and travel context of the study area points to relatively long commuter journeys that are predominately made by car. There is a significant outflow of traffic from Braintree District with 44% of usual residents commuting outside the district for work. This is in large part due to there being a higher number of workers resident in the district compared to jobs. This manifests itself in a relatively long average journey to work at 21.1km in 2011, an increase of 1.0km since 2001. After Greater London, the key destinations for commuter trips out of Braintree District are the surrounding districts of Chelmsford, Uttlesford and Colchester in that order. Aside from London, this outflow is predominately by car at between 86% and 92% of journeys. Taken together, these statistics point a comparatively high and increasing level of stress being applied on the Essex Priority Network (PR1) and national Strategic Roads Network (SRN) that provide for longer distance inter-urban travel.
A thorough analysis of the current transport related problems and their underlying cause reveals the following: • Corridor link infrastructure operates over-capacity during up to 5.75 hours per day. • Key junctions at Galley´s Corner roundabout and Mark Tey roundabout act as major pinch-points. • This lack of capacity relative to transport demand leads to significant congestion related delay and poor journey time reliability during a number of hours each day. • A combination of congestion and the narrow carriageway result in poor resilience. • In addition, this strategic corridor runs directly through a number of villages such as Bradwell, Broad Green and Marks Tey causing issues of severance and has a comparatively poor safety record.
If left unaddressed, these issues would all be exacerbated over time as the demand for transport on the strategic A120 corridor increases. This would likely act as a constraint on future growth in the region and locally and act as a barrier to growth for strategic developments in the region including Stansted Airport (London Stansted Airport: The UK’s Southern, MAG, 2013) and the Haven Ports - particularly Harwich International Port. It would also provide a barrier to the implementation of planned housing and jobs in the area. Increased congestion will also reduce accessibility for local residents to work and essential services while increasing the impact of noise and severance and reducing air quality.
A number of previous studies on the corridor were previously produced, one of which was presented at a public consultation with four options, resulting in a preferred route in 2005 that did not proceed to construction, largely due to cost and a lack of stakeholder consensus.
The Essex County Council Transport Strategy (2011-2026) identifies the following policy that is directly related to the A120 corridor: • Strategic Transport Priorities: Lobbying Government for enhancements to the A120 to access Harwich port and between the A12 and Braintree. Longer term dualling of the A120 would improve connectivity across northern Essex and provide essential network resilience for traffic accessing the Haven Ports by providing an alternative to the A12 and A14 in line with TEN-T22 ambitions to improve network efficiency.
Further details on planning policies can be found in section 4, Planning Factors.
In April 2015 Highways England published an updated East of England Route Strategy. Whilst identifying the A120 between Braintree and Marks Tey as one of the key challenges with the opportunity of widening to dual carriageway, this section has not been included in HE’s Road Investment Strategy.
Given the above problems, Essex County Council has committed to leading on a feasibility study to upgrade the A120 between Braintree Town and the A12. It has been agreed by Essex County Council, the Department for Transport (DfT) and Highways England that the county council will lead on the review of options and routes, public consultation on them and the subsequent identification of a preferred route for the scheme.
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2.3 Scheme Objectives
Specific objectives for the A120 scheme were identified by examining evidence of all transport relative issues, problems and their underlying causes and mapping these against potential objectives, then summarising these. These objectives along with an overview of the transport related problems and underlying causes identified were then presented at a workshop on the 16 th November 2015 to the project team, Highways England, Essex County Council, Braintree District Council, Colchester Borough Council and emergency services. At this workshop, the objectives were discussed and reviewed. A final set of intervention-specific objectives that were formally approved by the A120 Project Board in March 2016. These are listed in Table 1 below, together with the corresponding Highways England RIS objective.
A120 Braintree Town to Marks Tey Intervention Specific Objectives RIS Objectives
Reduce congestion related delay, improve journey time reliability and increase the overall transport capacity of the A120 corridor. Increase the resilience of the strategic transport network by improving the ability Reduce existing and of the A120 corridor to cope with incidents such as collisions, breakdowns, future levels of delay maintenance and flooding. and congestion Encourage alternatives to car travel through improvements to the attractiveness of public transport along the A120 corridor.
Provide and maintain physical infrastructure that facilitates housing and economic Support significant growth, enhances the strategic east-west link and enables businesses to flourish. levels of planned Improve connectivity within communities and integration with the wider transport growth expected in network by reducing severance and increasing accessibility for local residents. the area Address current road Improve safety for all road users and road workers within the A120 corridor. safety issues Minimise Improve the environmental impact of transport on communities along the existing environmental impact A120 corridor and reduce the impact of new infrastructure on the natural and built on sensitive environment by design. receptors(s) Improve the quality and connectivity of transport provision within the A120 Improve accessibility corridor for people using non-motorised forms of transport, such as pedestrians, for non-motorised cyclists and equestrians. users
Table 1: Mapping Project Objectives to Road Investment Strategy Objectives
2.4 Previous Work and Studies
The previous work and studies carried out in the corridor include the following: • A120 Feasibility Study Braintree to Marks Tey Stage 1: Review of evidence and identification of problems along the corridor. This study was undertaken by AECOM in 2015 for Highways England to assess the problems of the A120 corridor from the point of view of identifying more local and short to medium term improvements. • A120 Braintree to Marks Tey Improvement (2005) – a study during the early 2000’s was conducted to identify the problems on the corridor, develop and assess options for addressing the problems and undertaking public consultation to select a preferred option. Four options were put forward in a public consultation with the resulting preferred option being an off-line southern bypass. This option did not proceed to construction. It is understood that this was largely due to the high cost of the project given the
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economic climate of the time and due to local opposition. It should be noted that the public consultation process produced five alternate options plus an additional option proposed by Braintree Council. • A120 Galley’s Corner Local Network Management Scheme (LNMS) Workshop (Atkins, October 2009) - During 2009, Atkins identified a number of options to address congestion and road safety issues at Galley’s Corner. These included minor modifications to the roundabout, part signalisation, a slip road between A120 eastbound and Millennium Way and a scheme that would take the A120 off-line to the east of Galley’s Corner, providing a grade separated junction to the north-east. One of the options identified by Atkins has now been implemented, under the ‘pinch point’ scheme described below. (Source: AECOM 2015). • A120 Pinch Point Scheme (March 2014) - As part of the 2012 Autumn Statement, a Local Pinch-Point fund was established to remove bottlenecks on the local highway network. According to AECOM (2015) a Pinch-Point scheme was carried out in March 2014 to improve the capacity of the roundabout at Galley’s Corner. The scheme involved localised widening of the circulatory carriageway to encourage use of both circulatory lanes, coupled with improved signing and road markings. This was designed to ease the path for heavy goods vehicles through the junction and therefore increase the effective capacity of the A120 roundabout entries. • A120 Millennium Way Slip Roads (2013 – 2014) – During 2013, AECOM carried out initial pre-feasibility work on the potential for direct slip roads between the A120 to the west of Galley’s Corner and the B1018 Millennium Way, which crosses the A120 in the vicinity of Braintree Freeport. The objective of the scheme was to remove excess turning traffic from the roundabout and thereby free up capacity. Highways England has recently commissioned further work to establish the engineering feasibility of the scheme, land-take and departures from standard.
These studies have been used to provide context and technical input into the study.
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3. EXISTING CONDITIONS
3.1 Description of Locality The length of the A120 corridor under consideration runs from the east of the A120’s junction with London Road on the west side of Braintree (A131 junction), to the A12 at the Marks Tey roundabout covering a distance of approximately 13 miles. It forms a major east-west route across mid-Essex serving the towns of Colchester and Braintree as well as several villages along the route to include Marks Tey, Coggeshall and Bradwell. Further afield, it forms part of the wider A120 Trunk road connecting Harwich Port in the east with Stansted Airport and the M11 in the west. It links to another part of the Strategic Road Network at the A12 junction 25 via the Marks Tey and Prince of Wales roundabouts.
3.2 Existing Highway Network
Strategic Roads
Strategic roads are those routes that uphold national transport objectives, link major urban centres of population, provide access to ports, airports and other countries. They facilitate inter-regional connectivity and support the national economy. They consist of motorways and core trunk roads and are the responsibility of the Secretary of State for Transport. They are managed, maintained and improved by the Highways England on behalf of the Secretary of State.
Existing A120
The existing A120 from the M11/Stansted airport is dual carriageway with grade separated junctions until the A120 reaches Braintree and the Galley’s Corner roundabout. Galley’s Corner is an at-grade roundabout, after which the A120 continues north as a dual carriageway until the Marks Farm roundabout. The A120 continues east from the Marks Farm roundabout as a single carriageway road and joins the A12 at the Marks Tey Junction.
The section east of Mark’s Farm passes through the village of Bradwell, with a lowered speed limit and built up frontages. East of Bradwell, the route continues as a single carriageway rural route until joining the Coggeshall bypass. Coggeshall bypass is also single carriageway, and bypasses Coggeshall to the north until re-joining the original alignment at the east side of Coggeshall. The route continues eastwards to Marks Tey, travelling through Little Tey. The section beyond Little Tey has built up frontages and terminates at a roundabout on the west side of the A12 J25. It is subject to 40 mph and 30mph speed limits over parts of its length.
Apart from Coggeshall Bypass, the route has varied widths, inconsistent NMU facilities, and numerous direct accesses from properties and fields. The road width in the single carriageway section varies from 6 metres to 10 metres (including painted ghost islands) with verges and footways in places. The carriageway width generally varies as follows: • The section from A131 to Marks Farm roundabout is dual carriageway of about 7.5 metres in each direction with a hardstrip. • The section from Marks Farm to Gravel Pits (Bradwell) has a carriageway width of about 6.8 metres including a ghost island. • The section from Gravel Pits (Bradwell) to West Street (Coggeshall) has a carriageway width of about 7.2 metres that includes a ghost island and 7.0 metres elsewhere. • The section from West Street to East Street (Coggeshall bypass) has a carriageway width of about 7.2 metres including a ghost island and 7.0 metres elsewhere. • The section from East Street (Colchester Road) to Great Tey Road has a carriageway of about 6.8 to 7.0 metres. • The section from Great Tey Road to Marks Tey roundabout has a carriageway of about 6.0 metres.
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Widths between highway boundaries vary along the route between 10 metres and 30 metres, most typically around 13 metres. By means of comparison, a dual two lane all-purpose trunk road to Highways England standards would total 26 metres minimum, excluding any earthworks and be designed for a 120kph (70mph) design speed.
There are a number of at-grade priority junctions including B1024 Colne Road, West Street, and B1024 Colchester Road on Coggeshall Bypass, and approximately 20 on the remainder of the route. There is a mini roundabout at Ashbury Drive junction, Marks Tey.
There are three significant structures, the River Blackwater Bridge near Bradwell, the Great Eastern Main Line Bridge at Marks Tey and a pedestrian subway beyond Tilkey Road, Coggeshall. There are two pelican crossing (Marks Tey and Bradwell), and traffic signals at Galley’s Corner junction (A120/B1018).
Existing Major Junctions
There are a number of existing junctions on the A120 in the study area which will form a constraint to any highway improvement scheme: • Galley’s Corner Roundabout – A five arm at grade roundabout where the A120 meets the B1018 and local roads, to the south-east of Braintree. There is a large residential area to its north (off Cressing Road) and a major retail and industrial area to its west. To the south of the junction is the Fowler’s Farm Hotel complex and east of the junction is open countryside. • Marks Farm Roundabout – A four arm at grade roundabout connecting the A120 and A131 which has a Tesco superstore located to the south-west of the roundabout and residential properties to the north-west. To the east of the junction is open countryside. • B1024 Colne Road junction – a staggered at-grade priority junction on the Coggeshall Bypass. The junction is bounded by a distribution centre on the south side and residential property on the north side. • Marks Tey Junction (A12 Junction 25) – A staggered dumb-bell grade separated roundabout where the A120 joins the A12. The junction is in the centre of Marks Tey, to the north of the junction is Marks Tey Rail Station as well as residential properties, to the south are residential and commercial properties.
Existing A12 The existing A120 joins the existing A12 at Junction 25 of the A12 at Marks Tey. The A12 is part of the strategic road network and runs from just north of the Blackwall Tunnel to the coast of East Anglia linking the key settlements of; Brentwood, Chelmsford, Colchester, Ipswich, Lowestoft & Great Yarmouth. In the locality of the A120 the A12 varies in DMRB standards between Junctions 19 (Boreham) and 25 (Marks Tey), with a mixture of dual two lane and dual three lane carriageways. In some locations at-grade accesses to adjacent properties have been retained and there are a number of design elements which do not meet current DMRB design standards. Regional Roads
The A120 corridor provides essential access to services and employment for various residents in villages and towns. The main towns in the district are Braintree, Witham, Halstead and Great Notley. The key service villages are Coggeshall, Erles Colne, Kelvedon and Silver End. The A131 is the main regional road, starting from the A130/ B1008 junction (near Little Waltham) and ending at the A134/ B1064 junction (by passing Sudbury). The A131 joins the existing A120 (between Great Notley and Braintree) at the Marks Farm junction and continues through Great Leighs until the A130/ B1008 junction. The A131 has a varied standard along its length, having been in part improved over time, with both single carriageway (S2AP) and dual carriageway (D2AP) sections with varying speed limits depending on the particular road section. The road is a single carriageway until joining the A120 at Marks Farm roundabout where it multiplexes with the A120 until the Panners/Great Notley junction where it diverges south on the single- carriageway (save for the initial length) Great Notley bypass.
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Local Roads A number of local roads which tend to have lower traffic densities than main trunk roads or A roads are located within the study area. Examples of these are the B1018 between the A120 at Galley’s Corner and Witham town centre (near to the A12) and two routes comprising of minor rural roads linking A120 Galley’s Corner with A12 at Rivenhall End, through the villages of Cressing and Silver End. These roads are relatively low standard single carriageway rural routes interspersed with village environments. The southern end of the B1018 enters the built- up area at Witham (B1389 junction) and is built-up at the northern end through Tye Green until reaching the final section, between Millennium Way and Galley’s Corner (urban dual carriageway). Millennium Way uses standard lane widths of 3.65m with varying verges are used with a grass central reserve utilised. Footways are only provided on one side of the road with hedges lining the boundary for some sections of Millennium Way (40mph limit). The B1256 starts at Birchanger Green and heads east right through Dunmow, Rayne and Braintree where it joins the A120 at the Marks Farm junction. The route varies through urban areas (becomes a restricted road particularly when going through Braintree) and rural areas (operates as an urban single carriageway SU2). Similarly the speed limit fluctuates between 30mph and 40mph depending on the road section. The footways are narrow in the rural areas with hedge boundaries whereas the urban areas provide wider footways. The B1024 starts of near Earls Colne (branching of the A1124) and continues southwards along Colne Road until meeting the A120 at Coggeshall. It continues southwards in between Kelvedon and Feering where it joins the A12 via London Road. The road category varies between single carriageways and restricted roads (30mph limit). Within the study area there is also a large network of unclassified roads which provide access to local farms and individual properties and hamlets, many being single track roads without any road markings.
Public Right of Ways (PRoWs)
Within the A120 study area there is a dense network of PRoWs including the presence of some long distance routes such as the Essex Way which runs from Harwich to Epping. For further details on the existing PRoWs refer to section 3.15.
3.3 Traffic
The existing traffic conditions have been described in detail in the Problems and Objectives Technical Note (Document Reference:B3553T41-JAC-GEN-00-RP-C-0003) which should be referred to for further information.
Trafficmaster data supplied by the Department for Transport (DfT) has been used to gain an understanding of the speeds and delays experienced along the A120 from Braintree to Marks Tey. The data used for the analysis consists of at least 80,000 observations for each hourly period during neutral months from September 2013 to August 2014. The section of the A120 analysed extends from the A131 at Great Notley to the A12 at Marks Tey which is about 13.0 miles in length.
Daily two-way traffic volumes (AADT) along the corridor between Marks Farm and the A12 at Marks Tey are relatively consistent, varying between about 21,400 and 25,400 vehicles per day. The proportion of heavy goods vehicles on the corridor is also relatively constant between Marks Farm roundabout and the A12 varying between 11.7% and 13.3% of AADT (using the definition in TRADS of HGVs of greater than 5.2 metres in length).
Peak hour traffic volumes (June 2014) are also relatively consistent and vary between about 1,950 and 2,300 two-way in the morning peak hour (0730 to 0830) and 1,670 and 2,160 in the evening peak hour (1700 to 1800).
Average speeds and journey time across the entire length of the corridor have also been calculated which are outlined in Table 2 below:
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Journey Times (minutes) Average Speed (mph)
A120 Direction of Travel 0800 - 1700 - 0800 - 1700 - Free Free Flow 0900 1800 0900 1800 Flow
Eastbound 22.3 30.8 16.4 35 25 47
Westbound 24.5 19.9 16.8 32 40 46
Table 2: Average Journey Times and Speeds in Peak Periods
Table 2 indicates the following key points: • Journey times are highest in the eastbound direction travelling from the A131 junction towards the A12 in the evening peak hour between 1700 and 1800, taking just over 30 minutes to travel the entire corridor at an average speed of 25 mph. • This compares to an average free flow journey time of about 16 minutes at 47 mph. • In the morning peak hour, the journey takes about 22 minutes eastbound and 25 minutes westbound compared to about 16 minutes and 17 minutes respectively at free flow speeds.
From the review of existing traffic data areas with low average speeds and poor journey time reliability include:
• In the AM peak the W/B approach to Galleys Corner Roundabout
• In the AM peak the E/B approach to Marks Tey Roundabout
• In the PM peak the E/B approach to Galleys Corner Roundabout
• In the PM peak the E/B approach to Marks Tey Roundabout
3.4 Existing Safety Conditions Collision and casualty records attributed to A120 (west of Galleys Corner to A12 Marks Tey junction) during the period January 2011 to December 2015 inclusive have been analysed. Data has been taken from validated STATS 19 data received from Highways England’s system. The most recent five full year period of data has been chosen to provide greater statistical accuracy, and to enable use of other annual data (such as traffic flows) within similar periods. It should be noted that for the local road network in the study area, and for collision cluster identification, the data set is currently based on 2010-2014 and will be updated at later project stages.
During the period covered, a total of 172 collisions has been recorded in the length of the A120 reviewed, resulting in 266 casualties (2011-2015 data). In the wider study area, a further 69 collisions occurred on the length of A12 in the study area, and 71 on local roads (2010-2014 data).
The document ‘Reported Casualties on the Strategic Network, 2013 (v1.4 dated 19th November 2014) has been used for comparative analysis, based on the years 2011-2013 unless otherwise stated.
Plans showing the locations and severity of collisions on the existing A120 are shown in Appendix C This analysis updates and enhances previous work carried out and included in the Options Assessment Report, and includes an updated data baseline from 2010-2014 to 2011-2015 for the SRN.
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Collision Analysis
The table below shows an overall collision analysis by year and severity for the lengths of SRN and also for local roads in the study area. This shows that on A120, the level of collisions was higher than the five year average significantly in 2014 and marginally in 2015. The level of (Killed or Seriously Injured) KSIs (the total of fatal and serious collisions) was higher in 2014. Collisions on the A12 and local roads do not show significant variation, year on year.
Strategic Road Network
Collisions Fatal Serious Slight Total
2011 0 7 24 31
2012 1 5 20 26
2013 0 6 24 30
2014 0 12 35 47
2015 0 3 35 38
Total 1 33 138 172
5 year average 0.2 6.6 27.6 34.4
Table 3: Collisions by year and severity (A120)
Collisions Fatal Serious Slight Total
2010 1 2 3 6
2011 1 4 14 19
2012 0 2 14 16
2013 1 3 12 16
2014 0 2 10 12
Total 3 13 53 69
5 year average 0.6 2.6 10.6 13.8
Table 4: Collisions by year and severity (A12 NB – 2010 – 2014)
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Local Roads
Fatal Serious Slight Total Collisions
2010 0 1 10 11
2011 0 1 16 17
2012 0 1 12 13
2013 0 1 13 14
2014 1 3 12 16
Total 1 7 63 71
5 year average 0.2 1.4 12.6 14.2
Table 5: Collisions by year and severity (Local roads in study area – 2010 – 2014)
Collision Clusters
The locations of clusters of collisions have been analysed for the period January 2010 to December 2014 and clusters of collisions identified. These have been sub-split by location on strategic roads or local (County Council) roads. 7 collision clusters are identified on the SRN in the study area, and shown in Table 6 below, and also in the plans in Appendix C (note collision cluster A12/007 is not shown on plans). A further 4 collision clusters are identified on the local road network in the study area.
The tables below list the collision clusters identified, and are separated according to occurrence on the SRN (A120 or A12), or the local road network. The collision clusters account for 99 collisions on strategic roads in the study area and 27 collisions on local roads in the study area.
65 collisions occurred at cluster locations on the A120 in the study area. 15 of these were KSIs (a rate of 23%) – The SRN KSI rate norm for 2011 – 2013 was 16%. The fatal weighted index is shown for each location, and indicates the Marks Tey junction (including A12 collisions) to have the highest FWI of the locations. A120/B1024 Colne Road junction, near Coggeshall has the highest FWI on the A120, 8 of the 11 collisions involving KSI casualties.
The fatal weighted index (FWI) weights collisions by severity roughly in the proportions which occur nationally, and highlights those sections which have the highest levels of these collisions. The FWI value is calculated as follows:-
Fatal Collisions = number x 1; Serious Collisions = number x 0.1; Slight Collisions = number x 0.01
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Fatal Total KSI Cluster Weighted Location Collisions Collisions Number Index 2010-2014 2010-2014 (FWI) A120/001 A120/Cressing Road – Galley’s Corner 21 2 0.39 Roundabout
A120/002 A120/A131/Coggeshall Road – Mark’s Farm 10 3 0.37 Roundabout
A120/003 A120/Coggeshall Road/King’s Lane 11 2 0.29
A120/004 A120/B1024 Colne Road, near Coggeshall 11 8 0.83
A120/005 A120/Salmons Lane, Salmon’s Corner 6 0 0.06
A120/006 A120/A12 Mark’s Tey Junction * 27 4 2.43
A120/006a A120/A12 Mark’s Tey West Roundabout* 6 0 0.06 A12/007 A12/Oak Road – Rivenhall End 10 1 0.19
Total collisions at SRN cluster locations 99 20 * NB some collisions listed are attributed to A12 – collisions in location A12/006a are included in A12/006
Table 6: Collision clusters by SRN Location (by collision severity)
Fatal Total KSI Cluster Weighted Location Collisions Collisions Number Index 2010-2014 2010-2014 (FWI) LR/008 B1018/The Avenue/ Avenue Road, Witham 10 0 0.10 B1018/Cypress Road/Rickstones Road, LR/009 5 2 Witham 0.23
LR/010 B1018 Witham Road/Temple Lane 7 1 0.16
LR/011 Cressing Road/Chapel Hill, Braintree 5 2 0.23 Total collisions at local road cluster locations 27 5 0.72
Table 7: Collision clusters by Local Road Location (by collision severity)
Casualty Analysis
Strategic Road Network
The tables below show an overall casualty analysis by year and severity for the lengths of A120, A12 and also for local roads. This shows that on A120, the level of casualties was higher than the five year average in 2014 and 2015, and that the level of KSIs was significantly higher in 2014 with a fatality in 2012. Casualties on A12 showed peaks in 2011 and 2013, but on local roads, peaks in 2012 and 2014. The fluctuations shown in the casualty levels year on year are slightly different from the collision levels.
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Year Fatal Serious Slight Total
2011 0 7 37 44
2012 1 5 39 45
2013 0 8 45 53
2014 0 16 53 69
2015 0 3 53 55
Total 1 39 227 266
5 year average 0.2 7.8 45.4 53.2
Table 8: Casualties by year and severity - A120 Year Fatal Serious Slight Total
2010 1 4 5 10
2011 1 5 22 28
2012 0 2 20 22
2013 1 5 20 26
2014 0 1 21 22
Total 3 17 88 108
5 year average 1 3.4 17.6 21.6
Table 9: Casualties by year and severity (A12 2010 – 2014) Year Fatal Serious Slight Total
2010 0 1 10 11
2011 0 1 18 19
2012 0 1 20 21
2013 0 1 15 16
2014 1 3 20 24
Total 1 7 83 91
5 year average 0.2 1.4 16.6 18.2
Table 10: Casualties by year and severity (Local roads in study area 2010 – 2014)
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Casualty Rate An indication of the level of risk can be obtained by introducing the length of the links and the traffic flow. Casualty rates for all casualties and for KSI casualties for A120 are shown in the table below, per hundred million vehicle miles (HMVM). The data is based on 2011-2013 performance to enable direct comparison with average rates for SRN dual carriageways (non-motorway) published by Highways England in 2014. Additionally, the fatal weighted index is shown. The fatal weighted index weights collisions by severity roughly in proportions which occur nationally, and highlights those sections which have the highest levels of these collisions. The value is calculated as detailed previously in this section.
The links which performed worse than national SRN levels are highlighted red in the table below, and give an indication of areas where improvement would be most likely to contribute to Highways England’s KPI to reduce KSI casualties. The dual carriageway rates should be treated with caution as only a relatively short length of route is involved and it includes two junction collision cluster locations (Galleys Corner and Marks Farm). The table shows the following highlights:-
1. The KSI rate per hundred million vehicle miles (hmvm) was higher than the SRN norm on the dual carriageway and single carriageway sections of A120. 2. The casualty rate per hundred million vehicle miles (hmvm) was higher than the SRN norm on the dual carriageway and single carriageway sections of A120. 3. The FWI rate per hmvm was higher than the SRN norm on the A120 dual carriageway link.
SRN SRN SRN KSI KSI Casualty Collision FWI FWI Casualties Fatal Serious Slight Total rate/ rate/ rate/ rate/ rate/ rate/ hmvm hmvm Hmvm hmvm hmvm hmvm A120 (single 1 15 105 121 6.72 5.56 50.81 31.70 0.92 1.65 carriageway) A120 ( dual 0 5 16 21 8.33 2.86 34.91 26.32 1.10 0.80 carriageway)
Table 11: Casualty Rates, KSI and FWI rates per hundred million vehicle miles by year (2011 – 2013)
Non-Motorised User Collisions
There is a low level of NMU collisions on the A120, accounting for 13 out of the total of 172 collisions (7.6%). This compares with a national level of 23% for the period 2011 - 2014 (source - Reported Road Casualties Great Britain: 2015 – Annual Report – Table RAS 30001).
However, of these collisions, 8 were located in the section between Salmons Lane and the A12 junction, in Marks Tey. This majority of this section of route is subject to a 40 m.p.h. speed limit and has semi built-up or built-up frontages. NMU collisions represent 8 of the 40 collisions in this section of route in the study period, which is slightly lower than the national level (20% against 23% nationally).
A further cycle collision occurred in the study period in the village of Bradwell, also in a built-up area subject to a 40 m.p.h. speed limit.
The level of KSI NMU collisions compared with all NMU collisions on A120 is 31%. This compares with the national norm for 2011 – 2014 of 20% (source – Department for Transport - Reported Road Casualties Great Britain: 2015 – Annual Report – Table RAS 30001). However, it compares favourably with the national SRN value for the period 2011 – 2013 of 40% (source – Highways England - Reported Road Casualties on the Strategic Network 2013 – Appendices – Tables C-8 and C-9). It is possible this variation could be explained by the national SRN values occurring generally on higher speed roads, whereas the nationwide figures include all built-up roads. For A120, nearly 70% of collisions occurred on sections subject to a 40 m.p.h. speed limit.
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Collisions Fatal Serious Slight Total
2011 0 0 1 1
2012 0 0 3 3
2013 0 1 3 4
2014 0 3 1 4
2015 0 0 1 1
Total 0 4 9 13
Table 12: A120 Non-Motorised User Collisions and Casualties (2011 – 2015) General Collision Analysis (A120)
The following analyses are only related to the 172 collisions recorded on the A120 and document a range of standard analyses which can identify route issues.
The number of collisions during the hours of darkness is shown in the table below, which for the comparative period is 22% and is lower than the SRN norm of 24%.
2011 2012 2013 2014 2015 Total
Darkness 11 3 6 12 8 38
Daylight 20 23 24 35 30 132
Total 31 26 30 47 38 172
% Dark 22%
Table 13: A120 Collisions by daylight / darkness by year The table below shows the number of collisions on a wet road surface. For ease of presentation, ‘wet’ road surface has been recorded when the road surface was listed as Ice / Flood / Snow and this has also been reflected in the National SRN comparison value of 32% (2011-2013). The comparative value for the route is lower than this, at 24%.
2011 2012 2013 2014 2015 Total
Wet 8 6 6 12 10 42
Dry 23 20 24 35 28 130
Total 31 26 30 47 38 172
% Wet 24%
Table 14: A120 Collisions by wet or dry road surface condition by year
The following table shows collisions by time period. In the absence of hourly traffic flow data currently, it is considered that the peak AM period is 07:00-09:00 and peak PM period 16:00-18:00. When combined, these
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time periods represent 49 (28%) collisions within the A120. However, the time periods 1200:1300 and 15:00 to 16:00 have the largest collision numbers.
Total Total
00:00-01:00 0 12:00-13:00 18
01:00-02:00 2 13:00-14:00 17
02:00-03:00 0 14:00-15:00 12
03:00-04:00 0 15:00-16:00 18
04:00-05:00 1 16:00-17:00 16
05:00-06:00 0 17:00-18:00 14
06:00-07:00 4 18:00-19:00 11
07:00-08:00 5 19:00-20:00 6
08:00-09:00 14 20:00-21:00 2
09:00-10:00 10 21:00-22:00 1
10:00-11:00 11 22:00-23:00 2
11:00-12:00 5 23:00-00:00 2
Table 15: A120 Collisions by Time of Day by Year In order to compare the above to National values 1 the time periods have been grouped as shown in the table below. This indicates that on A120, the collision levels during the periods 10:00 to 14:00 and 14:00 to 18:00 have higher proportions of collisions than the SRN norm.
Time Period Section % SRN %
00:00 – 06:00 2 8
06:00 – 10:00 19 23
10:00 – 14:00 30 21
14:00 – 18:00 35 29
18:00 – 00:00 14 19
Table 16: A120 Collisions by Time Period compared with SRN norm The final analysis undertaken related to the vehicles involved in the collisions:
1 Table B-4 Collisions by time period, day and year - Reported Road Casualties on the Strategic Network 2013’
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Pedal Cycle Cycle Pedal Goods Vehicle Motorcycle Total Grand Agricultural Agricultural Bus/Coach Bus/Coach Known Not Taxi Car Car >125cc- >50cc – >50cc >500cc >500cc >3.5t – >3.5t – <50cc <50cc 125cc 125cc 500cc <3.5t <3.5t <7.5t >7.5t
Study 1 477 49 3 32 6 10 8 15 6 1 2 11 621 Area
Table 17: A120 Scheme Study Area – Vehicles Involved The definition of a Heavy Goods Vehicle in Reported Road Casualties on the Strategic Network 2013 is any vehicle being of more than 3.5 tonnes in weight, and 35 (5.6%) of all vehicles involved in the collisions for the period reviewed. The National level 2 is 10%, indicating a low level of goods vehicle involvement in collisions on in this area.
Powered Two Wheelers account for 39 (6.3%) of the vehicles which is marginally above the National value of 4%. Pedal Cyclists accounted for 11 vehicles (1.8%) which is above the National value of 0.7% but not considered significant based on the very low number of vehicles recorded.
Casualty Analysis An analysis has been carried out of casualty categories resulting from collisions in the study area. This is shown in the table below. This is based on the period 2010-2015.
Casualty Type Total Casualty Type Total
Car driver 186 Car passenger 108
Driver – Vehicle <3.5T 12 Passenger – Vehicle <3.5T 2
Driver – Vehicle >3.5T 4 Passenger – Vehicle >3.5T 3
Driver – agricultural veh 1 Passenger – agricultural vehicle 0
Rider – Motor Cycle 30 Passenger – Motor Cycle 3
Pedal cycle rider 14 Other passenger 0
Other driver/rider 1 PSV passenger 0
PSV driver 0 Pedestrian 13
Total 376
Table 18: Study Area Casualty Analysis (2011 – 2015) The table below shows the top 5 contributory factors as recorded by the reporting officer (where applicable) for collisions on A120. A total of 30 different contributory factors were recorded, but many of these were shown in very low numbers. Contributory factors are provided at the discretion of the officer attending the scene and are subjective, and in some cases, may not be recorded. The data can therefore be considered indicative only.
2 Table E-1i&ii. Number of vehicles by vehicle type, collision severity and year - Reported Road Casualties on the Strategic Network 2013’
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Total Total Contributory Factor
405 Failed to Look Properly 66
406 Failed to Judge Other 32 Person’s Path or Speed
602 Careless, reckless or in 17 a hurry
403 Poor turn or 10 manoeuvre
308 Following too close 8
Grand Total 133
Table 19: Contributory Factors - A120
Incident Data
Incident data has been requested for A120 from the ASC contractor and is awaited.
Summary of Conclusions – Existing Safety Conditions
• One of the key objectives of the scheme will be to reduce the number of KSIs. The KSI rate per hundred million vehicle miles on both the dual and single carriageway A120 links is higher than the national SRN norm for a similar road. • One of the key objectives of the scheme will be to reduce the number of KSIs. The casualty rate per hundred million vehicle miles on both the dual and single carriageway A120 links is higher than the national SRN norm for a similar road. • The fatal weighted index per hundred million vehicle miles on the dual carriageway A120 link is higher than the SRN norm for a similar road. • The collision cluster analysis has identified A120/B1024 Colne Road junction as showing the highest FWI of all of the collision clusters at 0.83 over a five year period. • The highest annual levels of collisions occurred on A120 in 2014 and 2015. • The level of collisions which occurred during the time period 1000:1800 is higher than the SRN norm. • The highest numbers of collisions occur between 1200 and 1300, and between 1500 and 1600.
3.5 Topography, Land Use, Property Industry
The majority of the land use within the route corridor is predominantly agricultural with soil classifications of approximately Grade 2 (very good) and Grade 3a (good). There are pockets of grade 3 (good to moderate) land around Kelvedon. The A12 generally overlies Grade 2 (very good) agricultural land which is classed as the Best and Most Versatile (BMV) land; described as land with minor limitations which affect crop yield, cultivations or harvesting.
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3.6 Climate
The A120 Braintree to A12 area has climate typical of Eastern England; the region has mean annual temperatures of around 9.5 °C to 10.5 °C, where January and February tends to be the coldest months with average minimum temperatures of 1 °C. The average mean daily temperatures are around 6 °C to 8 °C in the winter, and the summer months around 20 °C to 23 °C during July and August. The temperature is mostly dictated by the Gulf Stream Temperatures and sea temperatures. Notably, the highest known temperature recorded in the area was 37.3 °C in Cavendish, approximately 40km north of Chelmsford, on 10 August 2003.
On average, December is the month with the least sunshine and July is the sunniest. Eastern England receives around 700 mm per year and includes some of the driest areas in the country compared to wettest places in England and Wales, like the Lake District, receiving an average of over 3000 mm of rain a year. The wettest month is October.
The number of annual thunderstorms makes a significant contribution to the total annual rainfall. They can occur at any time of year but are more frequent during the summer months. Over East Anglia, Lincolnshire and Humberside the average number of days of thunder per year is about 15 but varies from year to year.
Due to climate change, rainfall intensities are expected to increase over the design life of the Route Options. Therefore, a climate change uplift factor must be applied to incorporate resilience into the new surface water drainage (e.g. culvert crossings, cut-off ditches, carrier drain system, etc.) for each of the Route Options. Existing surface water drainage (e.g. culvert crossings, cut-off ditches, carrier drain system, etc.) to be retained will have to be assessed for climate change resilience to mitigate increasing flood risk to the scheme and surrounding area due to the expected increase in rainfall intensities associated with climate change.
3.7 Drainage
A desk study has briefly assessed the existing highway drainage using on-line aerial photography and Google “Streetview” imagery; due to the nature of the commission access to Highways England HADDMS (Highways Agency Drainage Data Management System) not being available to the project team. In any case, due to the unimproved nature of much of the existing A120 in the study area it is anticipated that the HADDMS system would only contain limited information.
Based on the visual inspection of the available online resources, the A120 road alignment in the study area appears to have a surface water drainage collection system along this entire road section.
The existing A120 between the A131 junction and Marks Farm Roundabout has a formal drainage system with kerbs and gullies believed to discharge into a piped drainage system, this in part being filter drain. Similar applies to the other improved section, the single carriageway Coggeshall Bypass.
The remainder of the existing, unimproved, A120 has a kerbed edge with gullies, the outfalls for which have not been ascertained at this stage - for much of the length it is anticipated that these may be local soakaways. In some discrete sections combined kerb drainage units have been installed, for instance the eastern approach to Marks Farm Roundabout and in Bradwell, possibly to overcome local issues with standing water on carriageway due to deficient carriageway longfall or crossfall.
There is a history of flooding on the A120 near Bradwell and there have recently been remedial works in the area including construction of new pipes and manholes and a new outfall along Bridge Hall Road/Water Lane to a ditch leading to the River Blackwater. Whilst this improvement should help to reduce pluvial flood events locally, with the existing A120 crossing the River Blackwater in Bradwell at relatively low elevation and on a relatively short bridge crossing that will restrict flow in flood events the existing A120 in this area will remain vulnerable to flooding from the river.
No pollution control or attenuation features are apparent on the existing A120 in the study area, though these may be obscured by vegetation cover.
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Local roads in the study area are predominantly un-kerbed, with no formal drainage system apparent.
It is recommended for subsequent project stages that further information on the existing surface water drainage network serving the study area:
• All available Highways England HADDMS information, the extent depending on route option selected (for off-line options only tie in locations may be required, for instance)
• Topographic and condition assessment (CCTV) surveys together with site inspections to verify the details and condition of the existing surface water drainage network serving the A120, the extent depending on route option selected
• As-built drawings available from the Local County/District Councils affected by the scheme
This information will be required to inform the surface water drainage design in subsequent project stages.
3.8 Geology
Overview of Site Geology
Sandy gravelly clay of the Lowestoft Formation overlies much of the study area and lies above the Kesgrave Formation of sand and gravel. The Kesgrave formation in turn lies above London Clay which is an overconsolidated clay. In locations where rivers are found alluvium is encountered within the floodplain. There is one geological Special Site of Scientific Interest (SSSI) within the route study area. The Marks Tey Brick Pit SSSI located to the north of Marks Tey is a uniquely important Pleistocene sediment, which has yielded a continuous pollen record through the entire Hoxnian Interglacial.
Bradwell Quarry is located in the middle of the study and is an operational sand and gravel quarry which can process up to 1 million m 3 of material per annum. The quarry has recently been granted planning permission to move into future reserve areas and has a further 3 areas in the Essex County Council (ECC) minerals plan. For further details on Bradwell Quarry refer to section 3.9.
Rivenhall Airfield is located next to Bradwell Quarry and was opened in 1942 serving as combat airfield used by both the RAF and the United States Air Force. It was closed in 1946 but remained in reserve until 1956, after which it was leased by Marconi. Due to the activity that has been conducted on this site there is the possibility for contamination, depending on the level of remediation conducted by Bradwell Quarry during mining operations.
There are no current landfill sites within the study, however there is one identified historic landfill located to the west of silver end.
Sources of Contamination
There are some sources of contamination within the study area which include a disused airfield which forms part of the Blackwater Quarry as discussed above. In addition pesticide warnings are found in some locations on the river Blackwater highlighting the risk of pesticides used by farmers. There are a number of historical gravel and sand pits within the study area which could form pockets of poorly compacted material which could create localised problems during construction; in addition these could be filled with contaminated materials.
3.9 Mining
The Essex Minerals Safeguarding Area (as defined in the Essex Minerals Plan 2014) forms a large part of the central study area. Clause 3.127 in the Plan states that ‘ If it proves necessary for development to take place within an MSA, then the presence of mineral resources and the potential for prior extraction of minerals should
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be considered. Where considered appropriate, prior extraction should be undertaken before development takes place. ’
In addition to the minerals safeguarding area there is also a large active quarry (Bradwell Quarry) in the study area. Bradwell Quarry has 5 separate areas in the Essex Minerals Plan. Areas A3 & A4 have already been granted planning permission and are located to the south east of the existing quarry. Areas A5 is identified as a preferred site in the Minerals Plan and Areas A6 & A7 is a reserve area that would only be considered if the Essex land bank fell below 7 years. Bradwell Quarry also has a reserve area A8 which is located to the south of Area A7, however this did not make it into the minerals plan.
To the south of Bradwell Quarry there is a potential minerals site called Park Gate Farm, which is a site submitted by Hanson for inclusion in the 2014 Minerals plan. This site is not a preferred site in the Minerals Plan however it does form part of the Minerals Safeguarding Area (MSA).
3.10 Public Utilities
The preliminary C2 Statutory Undertakers Inquiry (New Roads & Street Works Act 1991) was carried out to identify the extent of existing public utilities that would be affected by all options within the A120 Braintree to A12 study area. The C2 inquiries were sent out to all the Statutory Undertakers in the region who have responded with the location of their plant, which has enabled potential clashes at this initial stage to be identified.
The responses from the Utility companies indicated the presence of High Voltage cables (Overhead and Underground) associated with the Braintree Sub-station located to the south west of the existing Galleys Corner Roundabout as well as the presence of high pressure gas mains in the study area. In addition to these key apparatus there are also numerous Low Voltage Cables, BT cables and water mains that will be affected by all options in the study area. The list of potentially affected Statutory Undertakers apparatus is detailed in the Statutory Undertakers Estimate PCF Product (Document Reference: B3553T41-JAC-HGN-00-REP-C-0005).
At this stage of the project only C2 inquiries have been issued, no C3 budget estimates have been requested. The approach taken at this project stage has been to allocate a percentage of the works cost for required statutory undertakers diversions.
3.11 Technology
The existing A120 between Galleys Corner and the Marks Tey has very limited technology, to date the only identified assets include CCTV at Galleys Corner. The A12 in section that the A120 would tie into has a network of Emergency Roadside Telephones (ERTs) located at lay-bys as well as an network of average speed cameras between Rivenhall End and Easthorpe.
Once a preferred option is chosen then discussions will take place with HE’s Regional Control Centre (RCC) and the Regional Technology Maintenance Contractor to identify the full extent of technology assets in the scheme extents and how they are operated, which will help to inform the project proposals.
3.12 Existing Maintenance including Access Existing Maintenance Assessment and Strategy
Initial liaison has been carried out with Highways England Operations Directorate (OD) and to discuss existing maintenance strategies, challenges and opportunities. Information from OD and the Asset Support Contractor (ASC) on the existing maintenance regime is still awaited, however during this discussion it was identified that there were no usual maintenance activities carried out on this section of the network. This information will be reviewed during later project stages.
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Existing Maintenance and Accesses
Maintenance is carried out from within the highway boundary. Further information is awaited from HE OD and the ASC.
Existing significant structures on the Braintree Bypass in the study area include the River Brain culvert (Twain Culvert), the Braintree Branch Line Railway Overbridge, Millennium Way Overbridge and the pedestrian underpass immediately west of Galleys Corner Roundabout. Between Marks Farm roundabout and Marks Tey there are four significant structures, the River Blackwater Bridge near Bradwell, the Great Eastern Main Line Bridge at Marks Tey, a pedestrian subway beyond Tilkey Road, Coggeshall and a culvert for Robin’s Brook (Tilkey Culvert) located just to the west of the Tilkey subway.
Cyclic maintenance on the route poses particular challenges, especially in the single carriageway length owing to the level of traffic flow and the geometric standards, and the provision of appropriate traffic management facilities to provide adequate working space. Particular issues are associated with maintenance of drainage. The footway underpass near Tilkey Road has been reported as subject to flooding at times.
The existing A120 between Galleys Corner and Marks Tey has a number of Lay-bys to provide areas for short term stops and in emergencies.
Future Maintenance and Repair Strategy – Existing Route
A meeting has been held with HE OD and further information is awaited. Incident data is also awaited which will be reviewed at later project stages.
3.13 Environmental Status
There are a number of designations and constraints within the study areas of a number of the environmental topics. The study area for the existing environmental conditions is based on a Geographic Area of Impact (GAI) which has been determined using guidance from the DoT in the Transport Analysis Guidance (DfT, 2014). When route options are described in this section they are referring to the route options as described in sections 5.6 to 5.10 of this report and shown on drawing B3553T41-JAC-GEN-00-DR-Z-0006 contained in Appendix A.
The existing environmental designations within the study area are summarised in Table 20 and shown in Drawing B3553T41-JAC-HGI-00-GS-G-0131 found in Appendix A. A full description and location plans of the environmental designations are provided in the Environmental Assessment Report (Document Reference: B3553T41-JAC-EGN-00-REP-EN-0001)
Environmental Study Area Designation Description Issue
Air Quality None in the study area Air Quality 200m Management Area (AQMA) Scheduled There are two Scheduled Monuments, the Rivenhall Long monuments Mortuary Enclosure (Asset 121) and the Rivenhall Roman Villa site (Asset 85) of High Value. Grade II* Three Grade II* Listed Buildings, Black Notley Lodge (Asset 1), listed buildings Baytree Farmhouse (Asset 21) and Hole Farmhouse (Asset 126) Cultural Heritage 200m of High value.
Grade II listed 38 Grade II Listed Buildings of Medium value. buildings Conservation Three Conservation Areas, Stisted (Asset 39), Coggeshall (Asset areas 159) and Kelvedon (Asset 168) of Medium value
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Archaeological Four areas of archaeological remains of medium value. remains Local River Blackwater Special Landscape Area Landscape designations Non- Marks Hall Gardens and Arboretum, Glazenwood, Bradwell, designated Rivenhall Place, Holfield Grange, Prested Hall. historic gardens open to the public Conservation Braintree, Cressing, White Notley, Silver End, Stisted, Areas Coggeshall, Kelveden; Feering. Listed There are numerous listed buildings throughout the study area (as buildings, listed in cultural heritage above). Notable examples include: scheduled Grange Barn and Paycocks House (both Grade I listed) and monuments. Garden, Coggeshall – National Trust south of Coggeshall within conservation area. Includes circular walks published by National Trust which include Abbey grounds; and Landscape 1.5km Rivenhall Place – Grade II listed in 70 acres of parkland. Scheduled monuments include: Coggeshall Abbey (also Grade 1 listed building) – immediately south of Coggeshall; Land adjacent to St Peter & Paul Black Notley; Land adjacent to and including St Mary’s and All Saints, Rivenhall; and Cressing Temple Barns- approximately 1km south west of Silver End. Ancient Templeborder Wood (east of Braintree), Lanham Wood (west of woodlands Lanham Farm Road, south east of Braintree), Links Wood (south of Links Road near Clapdog Green), Storey Wood and nearby tree belt (south west of the Polish Camp, Woodhouse Lane), Bungate Wood (north east of Coggeshall), Great Monks Wood Common Land Lanham Green; (Lanham Green Common Land – The application for Common Land status has not been confirmed), Land by Dean’s Farm, Pantlings Lane. Ramsar Sites Abberton Reservoir Ramsar (6km distance), Blackwater Estuary Ramsar (9km), Colne Estuary Ramsar (13km), Dengie Ramsar 30km (16 km), Stour and Orwell Estuaries Ramsar (22km), Crouch and Roach Estuaries Ramsar (24km), Foulness Ramsar (28km), Hamford Water Ramsar (29km). Local Nature Hoppit Mead, Brockwell Meadows, Cuckoo Wood Reserves Local Wildlife Hoppit Mead Templeborder Wood, Lanham Wood, Link’s Wood, Nature Sites Maxey’s Spring, Storey’s Wood, Upney Wood, Barrowfield Wood, Conservation Hoo Hall Meadow, Brockwell Meadow, Kelvedon Hall Meadows, Within 1km of Braxted Park, Tikey Road Coggeshall, Blackwater Planation West, routes Blackwater Plantation, Park house Meadow, The Squire’s Plantation, Feering Marsh. Ancient Lanham Wood, Templeborder Wood, Links Wood, Storey’s Wood, Woodland Barrowfield Wood, Kelvedon Hall Meadows Veteran Trees ID no. 9183, ID no. 9202, ID no. 8452, ID no. 8439, ID no. 25555, ID no. 11390, ID no. 28382, ID no. 9250, ID no. 8456
Table 20: Environmental Designations
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3.14 Environment
3.14.1 Air Quality and Carbon Emissions
The background annual mean concentrations of NOx, NO 2 and PM10 for each assessment year (2015 and 2026) were obtained from Defra’s Background Maps, which are based on monitoring and meteorological data for a 2013 reference year. Background annual mean pollutant concentrations for the baseline and opening years were found to be well below respective objective thresholds.
In addition to desktop data monitoring was undertaken around the existing A120. Estimated annual mean equivalent NO 2 concentrations at all of the monitored sites were found to be below objective thresholds. Braintree District Council and Colchester Borough Council operate a network of diffusion tubes across their respective authority areas. NO2 concentrations at locations close to the major road networks were found to be below objective thresholds. One site shows exceedance in 2011 and this is along the existing A120 carriageway.
3.14.2 Cultural Heritage
Following guidance in HA208/07 Vol 11, Section 3, Part 2 (Highways Agency et al., 2007) 3 a topic study area extending 200m in all directions from the footprint of each route option has been used. This includes non- designated and designated heritage assets.
Within the topic study area 193 cultural heritage assets have been identified, of which 43 are designated. The NPPF defines designated sites as World Heritage Sites, Scheduled Monuments, Listed Buildings, Protected Wreck Sites, Registered Parks and Gardens, Registered Battlefields or Conservation Areas designated under the relevant legislation. These are as follows: • There are two Scheduled Monuments, the Rivenhall Long Mortuary Enclosure (Asset 121) and the Rivenhall Roman Villa site (Asset 85), both assessed to be of High Value; • There are three Grade II* Listed Buildings, Black Notley Lodge (Asset 1), Baytree Farmhouse (Asset 21) and Hole Farmhouse (Asset 126) which have also been assessed to be of High value; • Three Conservation Areas, Stisted (Asset 39), Coggeshall (Asset 159) and Kelvedon (Asset 168) have been assessed as Medium value; and • A further 38 Grade II Listed Buildings are also assessed as Medium value.
There are a further four areas of archaeological remains which have been assessed to be of medium value. The significance of understanding complex cropmarks (cropmarks are a means by which sub-surface remains, such as ditches or walls, may be visible from the air) is identified as an overarching research topic in the Research Framework (East Anglian Archaeology, 2011, p.84 4). Therefore, the complex cropmarks with a wide range of features present at Bradwell (Asset 24) and near Hole Farm (Asset 125) have been assessed as medium value.
The East of England Regional Research Framework identifies the significance of the Roman to Anglo Saxon transition in the East of England and states that “characterising the actual nature of settlement forms and patterns, material culture and so on for the 4 th and 5 th centuries AD in this region is of major national and international importance with regard to assessing the impact or otherwise of Germanic settlers .” (East Anglian Archaeology, 2011, p.48). This indicates that the unscheduled area surrounding Rivenhall Roman Villa (Asset 84), which has features covering these dates, can contribute to the Research Framework topics and is therefore assessed as medium value.
An area of prehistoric occupation within Braintree at Mill Hill (Asset 3) was partially excavated in 1999, with Bronze Age and Iron Age features present. The opportunity to examine sites relating to the transition from Bronze Age to Iron Age and the opportunity to carry out targeted environmental analysis of Bronze Age sediments is identified as an area of research in the Research Framework (East Anglian Archaeology, 2011, pp.20 - 21); therefore Mill Hill (Asset 3) is assessed as medium value.
3 Highways Agency et al., (2007), Volume 11, Section 3, Part 2 ‘Cultural Heritage’ (HA 208/07) of the Design Manual for Roads and Bridges 4 East Anglian Archaeology, Occasional Paper 24 (2011), Research and Archaeology Revisited: A revised framework for the East of England;
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The values of all cultural heritage assets are presented in summary in Table 21 below.
Sub-topic Negligi Low Medium High Very All ble High Values Total Archaeological 101 39 4 2 Scheduled 0 - Remains Monuments Historic - 3 41 (Grade II 3 Grade II* 0 - Buildings Listed Listed Buildings and Buildings 3 Conservation Areas) TOTAL 101 42 45 5 0 193
Table 21: Summary of cultural heritage asset values
Within the topic study area are a large number of cropmarks and chance casual archaeological finds, indicating a rich and complex archaeological landscape. However as, not all archaeological features can be seen as cropmarks, this means that the potential for unknown archaeological remains within the topic study area is has been assessed to be high.
3.14.3 Landscape
Overall the study area is generally consistent in character and is largely made up of medium sized fields enclosed by numerous hedgerows. The land use is predominantly arable with some pasture. The Rivers Brain, Blackwater and Robins Brook run approximately north west to south east across the study area. These are associated riparian vegetation and pasture within the valleys where typically the land is steeper and/or wetter. There are numerous villages, farmsteads and rural houses, including many substantial historic houses, which are scattered throughout the area. The A120, A12 roads and railway lines are locally dominant, although away from these corridors the area is reasonably tranquil.
Landscape Designations
There are no national landscape designations such as Areas of Outstanding Natural Beauty (AONB) within the study area and the area does not fall within the Metropolitan Green Belt. The River Blackwater Special Landscape Area (SLA) lies within Maldon District to the east of the A12 near Kelvedon. There are a number of designated heritage features of landscape interest e.g. registered parks and gardens, conservation areas, listed buildings and scheduled monuments. These are listed in Table 20.
National Character Area Profile
The study area almost entirely lies within National Character Area (NCA) 86: South Suffolk and North Essex Clayland. NCA 86 is described as:
‘It is an ancient landscape of wooded arable countryside with a distinct sense of enclosure. The overall character is of a gently undulating, chalky boulder clay plateau, the undulations being caused by the numerous small-scale river valleys that dissect the plateau. There is a complex network of old species-rich hedgerows, ancient woods and parklands, meadows with streams and rivers that flow eastwards. Traditional irregular field patterns are still discernible over much of the area, despite field enlargements in the second half of the 20th century. The widespread moderately fertile, chalky clay soils give the vegetation a more or less calcareous character. Gravel and sand deposits under the clay are important geological features, often exposed during mineral extraction, which contribute to our understanding of ice-age environmental change.’
Part of the study area lies within NCA 111 Northern Thames Basin located around Colchester and generally to the east of the A12. However the part of NCA 111 within the study area is relatively small and the descriptions
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of the wider character area are generally considered unrepresentative. It is considered that the descriptions within the county and district landscape character assessments provide better coverage for this area.
County and District Landscape Character Assessment
Landscape character at the regional level is described in the Essex Landscape Character Assessment and at the local level by the Braintree, Brentwood, Chelmsford, Maldon and Uttlesford Landscape Character Assessments and Colchester Borough Landscape Character Assessment. A full description of the landscape character areas are given in the EAR.
Sensitive Visual Receptors
Visual receptors of high sensitivity include residents in settlements, scattered properties and farmsteads, users of public rights of way and users of public open space, registered parks and gardens, and other parks and garden with public access. The key visual receptors are shown in Table 22.
Key visual receptors Residents in scattered houses and farmsteads and in key settlements of: • Braintree • Cressing • Black Notley • White Notley • Tye Green • Bradwell • Pattiswick • Silver End • Stisted • Coggeshall • Kelveden • Feering • Witham • Marks Tey Residents in new developments allocated in the Local Plan at: • Marks Tey • South east of Braintree Public Rights of Way Users of the public rights of way network throughout the study area, notably the Essex Way long distance footpath (130km from Epping to Harwich) Users of Common Land at: • Lanham Green (Lanham Green Common Land – The application for Common Land status has not been confirmed.) • Pantlings Lane • Land at Deans Farm, Cressing Visitors to designated and non-designated parks and gardens and National Trust properties: • Braxted Park • Prested Hall
Table 22: Key Visual Receptors
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3.14.4 Nature Conservation
Statutory Designated Sites
There are no Ramsar sites, Special Areas of Conservation (SACs) or Special Protection Areas (SPAs) within the GAI or wider study area. However, there are sites subject to these designations, often overlapping similar geographical areas and designated for similar or associated qualifying features, which are connected to the Options. The closest designated site is Abberton Reservoir located approximately 6km to the south east of the nearest route option under consideration. The River Blackwater and water catchment area provides hydrological connectivity between the Options and the designated sites. Additionally, as the designated sites support migratory birds and which are among the qualifying features for the site designations, there is the potential for one of more species of bird to utilise habitats within the GAI. Given the level of designation, these sites are valued as Very High/ National for the purpose of assessment.
Non-Statutory Designated Sites
The proposed Options lie within 1km of Local Nature Reserves, Local Wildlife Sites, and Veteran trees, as described in Table 20. Based on the designations, the habitats, and the potential for protected species, these features have been valued as Medium / County importance at this stage as a precautionary approach.
Landscape Habitats
A number of habitats of principal importance were identified within the study area including:
• Coastal and floodplain grazing marsh
• Traditional orchards
• Deciduous woodland
A Phase 1 survey was undertaken in order to identify priority habitats or habitats of principal importance that are found within the A120 study area. These are summarised in Table 23.
Habitat Applicable Importance Valuation for Options assessment
Ancient woodland / All Options Listed as Habitat of Principal Importance High/ National semi –natural (Section 41 NERC Act 1006). broadleaved woodland Coastal and floodplain grazing marsh Traditional orchards Deciduous woodland Option 1B Species-Rich or All hedgerows are considered Habitats of High/ National ‘Important’ Hedgerows Principal Importance (Section 41 NERC Act Option 4B (according to the 2006), and are included on the Essex BAP. Hedgerow Regulations Additionally, qualifying hedgerows are Option 8 1997) protected under the Hedgerow Regulations 1997. Option 9A Loss of qualifying hedgerows would reduce the availability of this habitat type and affect the achievement of national targets.
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Habitat Applicable Importance Valuation for Options assessment All Options Species-Poor All hedgerows are listed as Habitats of Low / Local Hedgerows (including Principal Importance and are included in the defunct hedgerows, Essex BAP. and hedgerows with Hedgerows provide ecosystem functions, such trees) as wind breaks and connective habitat. However, they are of low ecological interest, supporting limited species assemblages and are set within or around arable fields of low ecological interest. Option 3 Scattered trees There are numerous Veteran Trees within the Low/ Local GAI, and many examples of mature trees that a Option 4B have the potential to support diverse biota and species of conservation interest. Option 8
Option 9A
Option 1B Semi – improved Lowland calcareous grassland is a Habitat of Medium/ County calcareous grassland Principal Importance (Section 41 NERC Act Option 4B 2006). All species rich grasslands are an Essex BAP habitat. Calcareous grasslands are scarce occurrence, mainly situated along the edges of roads. Where calcareous grassland occurs within the GAI of the Options, the areas have been subject to improvement and are not in favourable condition. The reduced ecological value due to condition is offset by the scarcity and confined extents of calcareous grassland within the County. All Options Running water Rivers and streams are listed as Habitats of High / National Principal Importance (Section 41 NERC Act 2006) and Rivers are included in the Essex BAP. Threats to the habitat include pollution and physical modification. Improvements include naturalising the rivers to restore function. Main Rivers are designated under the Water Framework Directive (2000/60/EC). The habitats corridors have the potential to support communities and species of conservation interest. All Options Ponds Ponds are a Habitat of Principal Importance Medium/ County (Section 41 NERC Act 2006). Ponds are not specifically listed in the Essex BAP. However, great crested newts, which depend on the ponds, are listed and the GCN listing advises that there is a lack of data on the number of ponds available for GCN.
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Habitat Applicable Importance Valuation for Options assessment All Options Arable fields, crops and Arable field margins are listed as a Habitat of Low / Site cultivated ground Principal Importance (Section 41 NERC Act 2006).The habitat is well represented within the wider landscape, is of low quality within the GAIs of all the Options, and would be relatively easily to replace or replicate. All Options Mixed woodland These habitats may support assemblages of Negligible/ Site plantation species of ecological interest, including species of conservation concern, either alone or in Dense scrub combination with other habitats. However, they Scattered scrub are not subject to prioritisation and are relatively easy to replicate and replace, and Neural; poor semi- well represented within Essex and the UK. improved and improved grassland Tall ruderals Option 1B Ephemeral/ short perennial Option 8
Option 9A
Option 1B Coniferous woodland Option 4B
Option 4B Quarry Option 1B
Amenity grassland All Options These habitats are of low ecological interest as Negligible / Site these features are well represented within the Buildings UK and have limited functionality at a generic Hardstanding level. Although specific buildings may be used to provide features for some species (i.e. roosting sites for bats, barn owls), that may be critical to support a population, any such buildings would need to be considered separately and following further survey and assessment.
Table 23: Habitats and Valuations
The Phase 1 survey identified habitats in all five Options that would support the same protected and notable species or groups of species. These are summarised in Table 24.
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Species or species Rationale Value group Plants No protected plants were identified during the Phase 1 surveys. However, absence of protected or notable species Low / Site cannot be assumed without further and comprehensive survey effort. Given the relatively low overall value of habitats within the GAI, a valuation of Low/ Site importance is probable.
Invertebrates White clawed crayfish Austropotamobius pallipes , a species of principal importance (NERC Act, 2006 Sch 41) and an Low / Local Essex BAP species. White clawed crayfish are not considered to have a viable future along the rivers in Essex due to competition and predation by the non-native American signal crayfish Pacifastacus leniusculus . Given the forecast of extinction, loss of the species on site would not affect the conservation status of the species at County level of higher.
Other notable aquatic and terrestrial invertebrates may be present, but given the low prevalence of quality habitats within Low/ Site the GAI, losses are unlikely to affect the conservation status of any such species at County or national scales. However, given the absence of information to support this, a precautionary value is considered appropriate at this Stage.
Great crested newts GCN are categorised as a species of Least Concern (IUCN) but are a species of principal importance (NERC Act, 2006 Medium / County Sch 41) and Essex BAP priority species. GCN are commonly distributed in the county and wider region. Farm ponds, a key habitat for GCN, however have declined greatly with the reduction of agricultural animal and have been highlighted in the natural area profile as an area for conservation objectives, which may threaten the prevalence and status of the species without the provision of other replacement habitats. Therefore they are considered vulnerable for the purpose of this assessment. Loss of populations on site is unlikely to be critical to the conservation status of these species at regional or UK scale, but is likely to be significant at county level as a targeted BAP species.
Reptiles (widespread The three reptile species confirmed on site are categorised as being of Least Concern (IUCN) but are UK priority species Low / Local species: slow worm (NERC Act, 2006 Sch 41). Reptiles are widespread and abundant within wider surrounds, including the motorway verge, Angius fragilis , adder and likely to be present within other connected habitat within wider landscape. Vipera berus , grass Loss of populations on site is unlikely to be critical to the conservation status of this species at county, regional or UK snake Natrix natrix , and scales. Therefore it is probable that the resident population would be of Low / Local importance only. viviparous lizard Zootoca vivipara )
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Species or species Rationale Value group Birds (breeding and There is insufficient information available to determine the importance of the site for species, given the highly mobile and High / National wintering) dynamic nature of this group. There are habitats within and adjacent to the study area that would be suitable to support bird species subject to legal protection and of high conservation value. Given those habitats are widely available, use of those habitats on either an occasional or year round basis by, any such species cannot be assumed or discounted at this stage. Therefore, on the basis of the precautionary principle, and until further surveys and stakeholder engagement can inform this assessment, a High / National valuation would be appropriate.
Bats Bat species are categorized as ‘Least Concern’ on the IUCN Red List. Common and soprano pipistrelle bats Pipistrellus High / National pipistrellus and Pipistrellus pygmaeus , are Essex BAP species and species of principal importance (NERC Act 2006, Sch 41). The East Anglian Plain has some of the largest bat hibernacula in Britain. Barbastelle Barbastella barbastellus, Bechstein`s Myotis bechsteinii ; noctule Nyctalus noctula ; brown long-eared Plecotus auritus ; greater horseshoe Rhinolophus ferrumequinum and lesser horseshoe Rhinolophus hipposideros bats are also protected under the NERC Act (Sch 41, 2006). Loss of most of the bat species on site is unlikely to be critical to the conservation status of those species at regional or UK scales, but is likely to be significant at county level as a targeted BAP species. However, given the limited range of distribution and rarity of Barbastelle in the UK, any impacts that could cause the loss or reduction in numbers of this species would probably affect the conservation status of the species at UK level. However, although also rare at European level, Barbastelle are widely distributed across Europe so loss at site level would not affect status at European scale. Therefore a High/ National valuation would be appropriate.
Badger Badgers are categorised as a species of Least Conservation concern (IUCN) and are widespread in the UK and the Low/ Local county. Loss of populations on site would not alter the conservation status of badger at County or higher levels.
Dormice Muscardinus Dormice are of Least Concern (IUCN) are a UK and Essex BAP priority species. Hedgerow and ancient woodland Medium / County avellanarius habitats that support the species are also subject to conservation objectives. Dormice are rare in Essex and loss of populations on site would affect the conservation status at county level. As it is not a stronghold, the status would not be affected at regional or national scales.
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Species or species Rationale Value group Water vole Water vole are categorised as being of least conservation concern (IUCN). It is a species of principal importance (NERC Medium / County Sch 41, 2006) and an Essex BAP species due to declining populations. They are widespread in Essex, often occurring along water ways. Threats include flood defense methods reducing bankside habitats in recent years, and mink predation. Programs of reintroduction, habitat enhancement and mink culls have been undertaken but current information is not available as to whether these measures have stabilized the conservation status of the species, or whether it is still considered to be in decline. Therefore a precautionary Medium/ County valuation has been considered appropriate.
Otter Otters are a species of principal importance (NERC Sch 41, 2006) and an Essex BAP species. They are common in Low / Local Essex, with most rivers being fully occupied following reintroduction, the cessation of hunting in 1960s and improvements in water quality. Therefore loss of individuals on site would not affect the conservation status of the species at County level or higher.
Other notable species There is potential for species of Principal Importance, including brown hare Lepus europaeus , pole cats Mustela putorius , Low / Site harvest mice Micromys minutus and hedgehogs Erinaceus europaeus and common toads Bufo bufo . Loss of populations on site is unlikely to be critical to the conservation status of this species at regional or UK scale.
Invasive species The spread of invasive species would be ecologically damaging to species and assemblages of conservation concern, Medium / County and is subject to legal penalties. Therefore the prevention in the spread would avoid loss of integrity or status of important receptors. Therefore a negative value of Medium/ County importance is considered appropriate.
Table 24: Protected and notable species recorded or potentially present
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Invasive Species
Himalayan balsam ( Impatiens glandulifera) was noted during the Phase 1 survey around the River Blackwater. However, other invasive species may be present in other areas. Himalayan balsam is listed on Schedule 9 of the Wildlife Conservation Act 1981, which makes it an offence to actively plant or otherwise cause the species to grow in the wild. Materials containing Himalayan balsam are classified as controlled waste under the Environmental Protection Act (EPA) 1990 and must be disposed of at appropriately licenced landfills.
3.14.5 Geology and Soils
A description of the underlying geology beneath the route is given in Section 3.8; therefore this section will focus on the hydrogeology and contamination potential for the route options.
Groundwater Abstraction licences and Registered Domestic Abstractions
There is one licenced groundwater abstraction well located directly on the eastern section of the proposed route options 1B, 3 and 4B at NGR TL 89170 21932. The abstraction well is located to the north of the eastern railway line and is a small sized abstraction used for irrigation purposes at Great Domsey farm.
Consultation undertaken with the EA indicates that seven registered domestic abstraction are located within 250m of the route associated mainly with residential properties located near the route options.
Groundwater Source Protection Zones (SPZ)
Based on the EA aquifer maps, there are no SPZ on the proposed route options or within 250m of the route options.
Hydrology
The proposed route options cross a number of watercourses. Two main rivers; River Blackwater and River Brain are located within the proposed route options. All the route options cross River Blackwater at different points and some of the route options (1B and 8) cross the River Brain at the western end of the route. The route options also cross other named and unnamed watercourses and there are three reservoirs within 250m of some of the route options. The proposed watercourses can act as pathways for transport of contaminants exposed during proposed road construction or as receptors of land contamination.
Surface Water Quality
The River Brain (west) and River Blackwater (east) where present on the route options are both classified by the Environment Agency as having Moderate ecological and Good chemical quality, but high levels of nitrates and phosphates. Migration of any land contamination (mobilised during road construction) to surface waters is anticipated and this is likely to degrade the current water quality. It is a statutory requirement to protect surface watercourses during any development.
Surface Water Abstraction Licences
Based on the EA maps, there are no surface water abstraction licences recorded directly on any of the proposed route options. However, there are five recorded within 250m of the route options.
Soil Resources
Based on the Natural England’s ALC map, much of the land along the proposed route options comprises Grade 2 (very good) agricultural land, defined as being among the ‘best and most versatile’. The key exceptions are the sections of the route near the floodplain of the River Blackwater and River Brain which are Grade 3 (good to moderate). Based on the ALC described above, soils located within the route options are of high quality and are required to be preserved during the proposed route construction to avoid degradation of the quality.
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Mineral Resources
Based on the Essex County Council – Essex Minerals plan (adopted in July 2014), four of the five routes being currently proposed are aligned through either current or future extraction areas of Bradwell Quarry (the exception being Option 3). Options 8 and 9A are located over a potential mineral site at Parkgate Farm - a site submitted by Hanson for inclusion in the ECC minerals plan, but not as yet included in the plan.
As a viable mineral resource is present on most of the route options, the A120 project will be required to prepare a minerals resource assessment plan. Pre-excavation of mineral resource is likely to be required by the ECC minerals team prior to the A120 Scheme construction to avoid the sterilisation of any mineral. It is understood from the scheme Design Engineers that the mineral resources will be extracted prior to the road construction.
Landfills and Waste Management sites
According to the EA website, there are no known current or historical landfill sites, waste transfer stations or waste management facilities on or within 250m of the proposed route options. The closest landfills (both of which are historical and not active landfill sites) are Chapel Hill Landfill located to the north of Braintree (near the western section of the route options) and Temple Lane landfills located in Silver End.
Land Contamination (Historic and Current Land Use)
A number of historic and current land uses which may represent potential contamination sources have been identified within 250m of the proposed route options. High risk areas include Bradwell Quarry and the disused Rivenhall Airfield. Lower risk sites include farms, sewage works, scrap yards, substations, railway line and small business. A full list of these is given in Chapter 10, Section 10.7.8 of the A120 EAR.
Unexploded Ordnance
Based on the review of Zetica’s Unexploded Bomb (UXB) Risk Map for Essex area (viewed online), some parts of each of the five route options (particularly the western areas) may be in a moderate bomb risk area. Due to the large scale of the map and the limited geographical references, it is not possible to accurately locate the route in relation to the risk areas. It is possible the risk of UXB may be higher in route options 1B, 4B, 8 and 9A which cross or are in proximity to the former Rivenhall Airfield site. A specialist UXB survey may be required for these options during the next stage of the project.
Land Stability
Land instability occurs from natural hazards (including landslides, ground subsidence and ground compression) or previous land use activities including mining. Limited information on land stability has been obtained from the review of the National Landslide Database (available on BGS GeoIndex Onshore Map) and the Coal Authority Interactive Map.
Both databases indicate that there are no landslides and high risk coal mining areas on and within 1 km of the route options. It is possible that the areas where the route options cross Bradwell Quarry may be at risk of ground instability due to the extraction of minerals and replacement with fill materials.
3.14.6 Materials The materials anticipated to be used include primary raw materials; secondary/ recycled raw materials and manufactured/ processed materials. The primary raw materials are likely to be aggregates. Most construction aggregates are produced from hard, strong rock formations by crushing to produce crushed rock aggregate or from naturally occurring particulate deposits such as sand and gravel. The most important sources of crushed rock in Britain are limestone (including dolomite), igneous rock and sandstone. Sand and gravel can be either land-won or marine dredged. Information on secondary/ recycled raw materials and manufactured/ processed materials is limited thus at this stage only primary aggregates have been considered.
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The East of England Aggregates Working Party: Annual Monitoring Report 5 identifies primary aggregate and mineral sources in the East of England which includes Essex. The report identifies that aggregates sales in Essex, Thurrock and Southend-on-Sea in 2013 amounted to 3.2 million tonnes and the aggregate reserves were 32.9 million tonnes. As of August 2012, there were 23 sand and gravel sites with a further four sand and gravel quarries which have permission to extract but were dormant in 2012. There are six quarries located within the Geographic Area of Impact (GAI). There is one existing quarry within the GAI; Bradwell Quarry, which is located south of the village of Bradwell between Braintree and Coggeshall. There are a further two quarries in the wider study area. These include: • Colchester Quarry (also known as Stanway Quarry) which is located approximately 3km to the south west of the Prince of Wales Roundabout, Marks Tey; • Birch Quarry, Maldon Road which lies to the south east of Marks Tey at the boundary of the 3km study area. In addition to these existing quarries, there are several areas designated as mineral consultation areas (MCAs) in the Essex Minerals Local Plan, close to Straits Mill Gravel Pit and around Marks Tey, Colchester and Birch quarries.
Based on current data and the information detailed in Table 25 there is unlikely to be primary aggregates available locally during the lifetime of the construction of the A120 Scheme. Construction of the A120 Scheme is estimated to commence in 2023 and may take approximately three years to complete. However, as shown in Table 25, there is landbank regionally until 2023 (10 years land bank from 2013).
Reserves (as at Annual call on Landbank (years) (as 31/12/13) reserves (2005-20) Sand & Gravel at 31/12/13) (thousand tonnes) (years)
Essex, Thurrock & Southend- 32,885 4,450 7.4 years on-Sea
East of England 146,878 14,750 10 years
Table 25: Land-won aggregates: reserves and landbanks 2013
Other materials needed for the A120 Scheme would have to be transported from areas further afield; for example, steel, plastic and pre-cast concrete elements.
3.14.7 Waste
ECC and SSBC identified 33 construction and demolition waste recycling sites within Essex in 2014, either operating or under construction. These are located mainly near urban areas and main transport routes and provide an estimated capacity of approximately 1.64 million tonnes per annum (tpa). There are generally fewer facilities located in rural areas, typically comprising temporary facilities co-located on operating minerals or landfill sites.
Table 26 provides a summary of the construction, demolition and excavation (CD&E) recycling capacity that is available within Essex. Additional capacity can be provided through the use of mobile plant. These are generally only in-use intermittently and may be at various locations. In 2014, it was estimated that there were approximately 20 mobile recycling plants registered in Essex. This has not been captured in Table 26 as it is difficult to assess accurately and capture information on the processing of mobile plants, nevertheless, it is likely that there would be additional capacity such facilities.
5 Department for Communities and Local Government, 2014
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Static CD&E Recycling Facilities Number of Estimated Total Facilities Capacity (tpa) in 2012/13 (2012/13) Operational and Facilities under Construction 33 1,636,237 All facilities with planning permission 38 1,704,362
Table 26: CD&E recycling facility capacity summary (Essex County Council, 2015)
Table 27 provides a summary of inert landfill capacity within Essex. There are no authorised landfills currently operating within the GAI. The wider study area includes four authorised landfills – Old House Farm, Dyers Mead Landfill Site, Bellhouse Landfill Site and Bellhouse Quarry (EA, 2015).
Capacity of those facilities solely Inert Landfills accepting inert waste (m 3) Current Operational Facilities 754,958 Current Operational Facilities and those commencing prior to 2,554,958 development All facilities with planning permission 2,554,958
Table 27: Inert landfill capacity summary
In 2012 there were 48 hazardous waste facilities operating in the ECC and SSBC Plan Area. Table 28 Error! Reference source not found. provides a summary of these facilities and primarily includes information on facilities that deal with Waste Electrical and Electronic Equipment (WEEE), asbestos or other metal recycling sites involved with vehicle dismantling. There are limited facilities dedicated to hazardous waste recovery.
There are a number of hazardous waste transfer facilities, which enable waste to be exported beyond the plan area boundary for further recovery and treatment activities. Within the plan area, there are no facilities for incineration with or without Energy from Waste (EfW) or treatment. Therefore, all hazardous waste requiring disposal to landfill will need to be exported out of Essex potentially to adjacent counties.
Broad Facility Total number of facilities Waste Accepted Type (2012) (tonnes) Transfer 13 5,407
Recovery 35 (31 metal recycling facilities & 4 treatment facilities) 32,128 Total 48 37,535
Table 28: Hazardous waste facilities
In 2012 there were 15 organic treatment and organic treatment with energy recovery facilities operating in ECC and SSBC Plan Area. Table 29 provides a summary of the planning permission throughput of the organic treatment sites within ECC.
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Organic treatment facilities Annual average based on quantities over 4 years (tonnes) In Vessel Composting 36,782
Open Windrow Composting 154,079 Anaerobic Digestion 180,000
Table 29: Organic treatment and organic treatment with energy recovery facilities summary
3.14.8 Noise and Vibration
With the exception of route option 3, the proposed scheme options transverse an area of countryside away from main roads. The existing noise environment in these areas are defined by local roads, aircraft from Stansted airport (the area falls under the Stansted airport flightpath, in particular departing aircraft), and due to the number of farmsteads in the area, it is likely that sources associated with farming will also contribute to the noise environment. Noise levels in these areas would generally be considered to be relatively low; however, would vary for each receptor depending, in particular, on proximity to minor roads, e.g. Kelvedon Road (B1024), Long Green, Braintree Road (B1018), and Boars Tye Road.
The route options will connect the A12 to the east and A120 at Braintree, both major sources of noise in the area. In addition, the existing A120 runs between the A12 and Braintree. The contribution of these sources of road traffic noise to a receptor’s noise environment would depend on a receptor’s proximity to either source. Receptors that are located adjacent to such roads will be exposed to high levels of road traffic noise. A number of these which are residential have been classified as Noise Important Areas (NIA) under the Defra Noise Action Planning Process. The following NIAs within the study area are shown in EAR Volume 2- Figures 12.1.1 - 12.5.6 and can be summarised as follows: • Properties adjacent to the A120 to the east and south of Braintree, Bradwell, Marks Tey and Coggeshall. In total approximately 220 properties are within NIAs adjacent to the A120 between Braintree and Marks Tey. • Properties adjacent to the A12 between Kelvedon and Marks Tey (junction 25 of A12). In total approximately 80 properties are within NIAs on this section of the A12. • Properties adjacent to the A12 north of junction 25 of A12. • Properties adjacent to the A131 to the east of Braintree, immediately north of the A120/A131 junction. In total approximately 30 properties are within NIAs on this section of the A131.
Receptors located in close proximity to main roads, such as the A120 and A12 have the potential to currently be exposed to perceptible levels of ground-borne vibration. These would largely emanate from heavy vehicles.
3.14.9 People and Communities
For each of the five options, all sensitive receptors within a 200m buffer of the route have been identified, with the exception of PRoWs. Only PRoWs directly intersected by the proposed alignments have been noted. Further work will be undertaken for at a later stage to identify PRoWs indirectly affected by the proposed scheme (i.e. reduction in amenity). The following provides an overview summary of the baseline environment for people and communities. A full description for each route is given in the A120 EAR, Chapter 13.7.
Public Rights of Way
A large number of public rights of way cross the route options. These include footpaths, cycleways, bridleways and the Essex Way.
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Vehicle Travellers (views from the road only) • Option 1B - from west to east, the route crosses the River Brain Valley and railway extending south of Braintree, medium sized arable fields and hedgerows, existing degraded landscape associated with Bradwell Quarry, the River Blackwater valley and the railway parallel to the existing A12. • Option 3 - from west to east, the route crosses the existing A120, the Blackwater valley, medium sized arable fields, hedgerows and vegetation associated with river corridors and the railway parallel to the existing A12. • Option 4B - from west to east, the route crosses agricultural field parcels, hedgerows, mature vegetation, existing degraded landscape associated with Bradwell Quarry, medium sized arable parcels and hedgerows, the River Blackwater valley and the railway parallel to the existing A12. • Option 8 - from west to east, the route crosses the River Brain valley and railway extending south of Braintree, medium sized arable fields and hedgerows and the railway parallel to the existing A12. • Option 9A - from west to east, the route crosses field parcels, mature vegetation, medium sized arable fields, hedgerows, the River Blackwater valley and the railway parallel to the existing A12.
Public Transport
There are a number of bus stops along the route options and bus routes on adjacent roads.
Private Property
The routes cross of number of residential areas. These include properties in Braintree, Tye Green, Cressing, Coggeshall, Feering and to the north of the A120.
Community Facilities
Community facilities in proximity to the route options include primary schools, a rugby club, Marks Tey Point-to- Point course and a motor cross track to the east of the A120.
Development Land/Planning Applications
Two major development/planning applications have been identified which may affect people and communities. These include the A12 Scheme and a new integrated waste management facility at Rivenhall Airfield/Bradwell Quarry.
Agricultural Land and Farms
A number of farmhouses have been identified along the route options. In addition, the majority of the buffer is located in agricultural land rated Grade 2 – Very Good, interspersed with areas of Grade 3 – Good to Moderate and urban.
Registered Common Land
Options 1B and 8 cross areas of Common Land at Deans Farm and Lanham Green (Lanham Green Common Land – The application for Common Land status has not been confirmed). Route 1B and 4B passes close to common land at Pantlings Lane.
3.14.10 Road Drainage and the Water Environment
The following provides a summary of the baseline for road drainage the water environment.
Fluvial flood risk
There are four watercourses that are designated as Main Rivers in the study area: the River Brain, the Rivenhall Brook, the River Blackwater and the Domsey Brook. The River Brain runs in a south-easterly direction from the
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north-west of Braintree and is fed by several tributaries along its length. The River Blackwater also flows in a south-easterly direction before flowing south to south-west after passing Coggeshall. Within the study area there are also a number of Ordinary Watercourses (non-statutory Main-River).
Groundwater flood risk
The Mid-Essex Strategic Flood Risk Assessment (SFRA) (Scott-Wilson, 2007) indicates there are no records of groundwater flooding available. There are no records of groundwater flooding along the proposed option routes and therefore the groundwater flood risk is classified as ‘Low’.
The Environment Agency’s ‘Areas Susceptible to Groundwater Flooding’ dataset identifies the majority of the study area, for all options, as being within zones with less than 25% of the area susceptible to groundwater flooding. However, the areas adjacent to the River Blackwater are typically classified as having a greater percentage of the area susceptible to groundwater flooding.
Sewer flood risk
Supporting figures to the Mid-Essex SFRA (Scott-Wilson, 2007) contain no records of sewer flooding within the study area.
Flood risk receptors
Table 30 provides an overview and classification of the value of each flood risk receptors identified within the study area and a description of the potential risk of flooding and the potential sensitivity/importance of the receptor.
Receptor Description Sensitivity/importance
Fluvial flood risk – River Brain and No residential properties in floodplain Low River Blackwater
Fluvial flood risk – ordinary Small corridor of Flood Zone 2 adjacent to named watercourses; Low watercourses however, no properties located within it within the study area
Surface water flood receptors Surface water flood risk to land adjacent to watercourses, no/very few Low properties within these areas identified as being at risk
Groundwater flood receptors Low groundwater flood risk across study area except for immediately Low adjacent to River Blackwater
Reservoir flood receptors Worst case scenario includes floodplain adjacent to River Blackwater Low with very few properties within
Other sources flood receptors No other risk sources noted at this stage Low
Table 30: Value of receptors for flood risk
Geomorphology and Water Quality There are a total of 28 watercourses (four of which are designated as ‘Main River’ by the Environment Agency; the remaining 24 are a combination of local field drains and small watercourses) potentially crossed or discharged to by the A120 scheme as well as two ponds and two lakes lying within the proposed options footprints. Typically the watercourses can be classified as a series of drains and small tributaries that feed the River Blackwater, River Brain and Domsey Brook, the three key watercourses within the study area. Table 31 provides an overview of the watercourses and their indicative importance (sensitivity) following completion of a desk study and initial site walkover.
The study area is predominantly rural with a number of small farm dwellings and small villages. Braintree is the main urban area within the study area, with urban runoff likely to feed into the River Brain and River Blackwater. The study area falls within a surface water safeguard zone (ID: SWSGZ434) for pesticides, and is within a
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Nitrate Vulnerable Zone (NVZ) for both surface waters and groundwater, which also includes the majority of northern Essex and Suffolk.
The study area lies within three Water Framework Directive water body catchments which are defined by the Environment Agency and given classifications based on the legislation. The water body status/potential is given a classification of Bad, Poor, Moderate or Good depending on the state of a number of quality elements, including biology, physico-chemical and hydromorphology. The statuses for the three water bodies are detailed below: • River Brain (GB105037041140) – Moderate Potential; • River Blackwater (Combined Essex) (GBB105037033870) – Moderate Potential; and • Domsey Brook (GB105037033870) – Good Potential.
Impacted route Receptor Description Importance options
River Brain Tributary of the River Blackwater. Noted on site to have a sinuous planform with Medium 1B, 8 a uniform, trapezoidal cross-section. Embanked in reaches
River Blackwater Sinuous planform with a pool-riffle sequence. Noted to become impacted by Medium 1B, 3, 4B, 8, 9A man-made activities in locale. Minimal areas of erosion and deposition observed
Domsey Brook Not observed on site. Catchment achieving Good Potential under the Water High 1B, 3, 4B Framework Directive
Robin’s Brook Observed to be a modified, straightened channel at the location surveyed with a Low 3 uniform cross-section.
Braintree Road Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 8 watercourse minimal vegetated riparian buffer
Ashes Road Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 8 watercourse (east) minimal vegetated riparian buffer
Ashes Road Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 8 watercourse (west) minimal vegetated riparian buffer
Ashes Farm Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 8 watercourse minimal vegetated riparian buffer
Rolphs Cottages Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 8, 9A watercourse minimal vegetated riparian buffer
Allshot’s Farm Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 1B watercourse some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Felixhall Park Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 1B, 4B watercourse some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Cogges Hall Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 4B watercourse minimal vegetated riparian buffer
Threadkells Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 1B, 4B watercourse minimal vegetated riparian buffer
Domsey Chase Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 1B, 3, 4B watercourse some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Unnamed Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 3, 4B watercourse some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Hanwick Farm Observed to be an incised and overgrown channel. Substantially shaded by Low 3
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Impacted route Receptor Description Importance options watercourse brambles, nettles and trees
Coggeshall Road Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 4B watercourse minimal vegetated riparian buffer
Prior’s Wood Modified watercourse with a trapezoidal cross-section. Typically embanked and Low 3 watercourse minimal vegetated riparian buffer
Doghouse Road Straightened road drain with grass lining. Dry in places at the time of survey Low 3 watercourse (east)
Woodland Straightened, over-deep field drain forming the boundary between agricultural Low 3 watercourse fields. Watercourse found to be dry at the time of survey
Tey Road Straightened watercourse with steep high banks. Substrate observed to consist Low 3 watercourse of silt, with some gravels in faster flowing reaches.
Old Road Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 3 watercourse some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Lanham Wood Small artificially straightened channel with an over-deep cross-section. Silt bed Low 3, 4B, 9A watercourse substrate
Park Road Small field drain with a straightened planform. Dry at the time of survey Low 8, 9A watercourse
Tributary 1 River Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 8, 9A Blackwater some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Tributary 2 River Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 8, 9A Blackwater some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Tributary 3 River Watercourse not surveyed. Aerial imagery suggests a sinuous planform with Low 9A Blackwater some riparian vegetated corridor. Importance score is indicative and to be confirmed on site
Links Road ponds Not surveyed to date. Appear to be small ponds located near the road Low 4B, 9A
Ambridge Road Not surveyed to date. Appear to be small ponds located near the road Low 3 pond
Braintree Road Not surveyed to date. Appear to be small ponds located near the road Low 1B, 8 pond
Unnamed pond Not surveyed to date. Appear to be small artificial ponds Low 3, 4B, 9A
Bradwell Quarry Not surveyed to date. A lake likely to be a former gravel pit located within Low 1B, 4B lake Bradwell Quarry
Long Green Road Not surveyed to date. Appears to be a medium size lake located near the road Low 3, 4B, 9A lake
Table 31: Baseline overview of watercourses, ponds and lakes
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3.15 Accessibility
3.15.1 Severance The existing route of A120 between Galleys Corner Roundabout and Mark’s Tey junction intersects with a number of public rights of way, footpaths and cycle facilities. Non-motorised users (NMUs) are categorised as pedestrians, cyclists, equestrians and powered wheelchairs for the purpose of this analysis.
Locations of existing facilities for non-motorised users are shown on the plan and profile drawings in Appendix B. Key areas of severance currently experienced for are:-
a) Marks Tey
• A120 separates the southern side of the route, which includes the A12 cycle path between Marks Tey and Kelvedon, from the railway station at the north side – crossing facilities are provided for pedestrians but not cyclists. • The railway bridge across the Great Eastern Main Line (GEML) has narrow footways and no cycle facilities. • The A12 separates the west and east parts of Marks Tey. A footbridge is provided but does not have cycle facilities.
b) Surrex to Marks Tey
• This length is inter-urban or urban has footway provision of variable width and lacks cycle provision. • Footways are not consistent throughout the southern side, particularly to the west of Motts Lane, Little Tey.
c) Coggeshall Bypass
• The Essex Way long distance footpath crosses the road at-grade. • Tilkey Underpass is subject to occasional flooding. • Several existing public rights of way (PROW) are severed.
d) Bradwell to Coggeshall
• Several existing PROWs join the route from either side. • Footways are inconsistent but are present on both sides in the village of Bradwell. • There are no cycle facilities. • There is a pelican crossing in Bradwell.
e) Bradwell to Marks Farm
• Footways are provided on both sides • A cycle lane is provided at Marks Farm roundabout (westbound approach)
f) Marks Farm to West of Galleys Corner
• The A120 dual carriageway generally separates the built-up area of Braintree from the rural area and villages to the south. • A shared footway/cycleway underpass is provided on the west side of Galleys Corner junction, which provides good access from Cressing Road to Millennium Way. • NMUs have to cross the Millennium Way arm of Galleys Corner roundabout to reach Long Green and the road to Cressing and Silver End. • Footpaths are severed by A120 west of Galleys Corner.
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3.15.2 Public Transport Accessibility Bus Services
Several bus routes operate in the network, and the major ones that could be affected by proposals in the A120 route corridor include:
a) Route 70 – Chelmsford-Braintree-Colchester – operates along A120 between Marks Tey, Coggeshall and Braintree (not on Coggeshall Bypass) (First (Essex); Regal Busways).
b) Route 82/82a – Colchester- Marks Tey-Colne Engaine – operates along A120 between Marks Tey and Great Tey (Hedingham Omnibuses)
c) Route 133a – Stansted Airport-Braintree-Colchester – operates along A120 between Marks Tey and Braintree – two early morning and two late evening limited stop journeys per day (Arriva (Network Colchester))
d) Route COG1 – Coggeshall to Kelvedon Station – morning and PM peak (Coggeshall Community Transport)
e) Route 38/38a – Halstead – Braintree – Witham via Tye Green, Silver End and Rivenhall (Stephensons of Essex)
f) A12 – various routes operate on A12
Bus stops are located on A120 between Marks Tey and the eastern end of the Coggeshall Bypass and in many cases, have bus lay bys. Bus stops are also located on A120 Between the western end of the Coggeshall Bypass and Mark Farm roundabout.
Bus stops are located on the A12 in the study area, but there are safety issues operating some of them, and crossing the road is hazardous, resulting in severance issues.
Rail Services
The Great Eastern mainline connects London to Colchester, Harwich, Ipswich and Norwich and has stations in Hatfield Peverel, Witham and Kelvedon. It crosses the eastern end of the A120 at Marks Tey.
There is also a branch line between Braintree Town and Witham, providing direct services between Braintree and London. Travel between Braintree Town, Colchester and further north and east is via a change at Witham Station. This branch line crosses the A120 between the A131 interchange and Galley’s Corner roundabout.
3.15.3 Non-Motorised User Safety Road traffic collisions and casualties have been assessed for the years 2011-2015, based on validated STATS 19 records. Full details of the analysis are contained in Section 3.4 ‘Existing Safety Conditions’ section of this Technical Appraisal Report. An extract is shown below, covering the section of the existing A120 route affected by the scheme.
There is a low level of NMU collisions on the A120, accounting for 13 out of the total of 171 collisions (7.6%). This compares with a national level of 23% for the period 2011 - 2014 (source - Reported Road Casualties Great Britain: 2015 – Annual Report – Table RAS 30001).
However, of these collisions, 8 were located in the section between Salmons Lane and the A12 junction, in Marks Tey. This majority of this section of route is subject to a 40 m.p.h. speed limit and has semi built-up or built-up frontages. NMU collisions represent 8 of the 40 collisions in this section of route in the study period, which is slightly lower than the national level (20% against 23% nationally).
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A further cycle collision occurred in the study period in the village of Bradwell, also in a built-up area subject to a 40 m.p.h. speed limit.
The level of KSI NMU collisions compared with all NMU collisions on A120 is 31%. This compares with unfavourably with the national norm for 2011 – 2014 of 20% (source – Department for Transport - Reported Road Casualties Great Britain: 2015 – Annual Report – Table RAS 30001). However, it compares favourably with the national SRN value for the period 2011 – 2013 of 40% (source – Highways England - Reported Road Casualties on the Strategic Network 2013 – Appendices – Tables C-8 and C-9). It is possible this variation could be explained by the national SRN values occurring generally on higher speed roads, whereas the nationwide figures include all built-up roads. For A120, nearly 70% of collisions occurred on sections with a 40 m.p.h. speed limit.
Collisions Fatal Serious Slight Total
2011 0 0 1 1
2012 0 0 3 3
2013 0 1 3 4
2014 0 3 1 4
2015 0 0 1 1
Total 0 4 9 13
Table 32: Non-Motorised User Collisions and Casualties – A120 (2011 – 2015)
3.16 Integration
3.16.1 Role within the Strategic Road Network
The A120 runs from the junction with A10 at its western end to Harwich port at the eastern end. The infrastructure varies considerably in standard between the A10 and Harwich. The section between the A131 on Braintree bypass and the A12 is about 13 miles (20.9km) in length and is predominantly a relatively narrow single carriageway road with the exception of the Braintree bypass.
The A120 plays a key role in connecting Stansted Airport with the east of England including the Haven Ports, in particular Harwich International Port. The route also forms part of the Trans-European Network carrying international traffic. At the regional level the corridor provides access to regional centres such as Colchester. At the local level the corridor provides the only access for many villages and towns along the route to essential services and employment.
3.16.2 International Transport Links
The A120 links two major international transport hubs; Stansted Airport and the Haven Gateway ports of Harwich and Felixstowe. Stansted Airport is situated in a mainly rural location on the A120 / M11 motorway and is London’s third largest airport for passengers and freight, flying 17.5 million passengers in 2013 and handling around 244,000 tonnes of freight each year. There are 10,200 employees on-site. (Source: Route Development Opportunities at London Stansted Airport, 2013). It is thus identified as a key economic driver in north Essex.
The Haven Gateway sub ‐region straddles parts of north-east Essex, including Braintree and south-east Suffolk. The sub ‐region is one of the key international gateways to the UK, containing the internationally significant Haven Ports at Harwich and Felixstowe.
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3.17 Maintenance and Repair Strategy Statement Maintenance and Repair Strategy Statement
Initial liaison has been carried out with Highways England Operations Directorate (OD) and existing maintenance strategies, challenges and opportunities considered. The potential maintenance challenges and opportunities proposed by the scheme options have been discussed in outline and are covered in ‘Maintenance Assessment’ (section 11).
The Maintenance and Repair Strategy Statement, which will be developed as a detailed PCF product at Stage 2, based on the preferred option, is designed to capture and analyse maintenance strategy for the proposed scheme and will contain maintenance philosophy statements for groups of infrastructure proposed. The strategy will be developed in close liaison with HE OD and the ASC.
It will be designed to discharge HE’s functions in respect of future maintenance under the Construction (Design and Management) Regulations, 2015 and to address HE’s objectives, that no-one will be harmed working on the Strategic Road Network (SRN) and the Aiming for Zero initiative. Interface with Operational Safety
Road worker safety is a core element dealt with in the PCF Safety Plan (PCF Stage 2). The Maintenance and Repair Strategy Statement will be a key product in the development of a safe scheme, and would be developed in co-ordination with other Health and Safety products (managed by the Principal Designer) and Operational Safety products including the Safety Plan (Stage 2), Combined Safety and Hazard Log Report (Stage 3) and Combined Operations Strategy (Stage 3). The Safety Plan would include selection of the appropriate safety management system (SMS). Any maintenance risks identified would be considered as part of the Combined Safety and Hazard Log Report and managed accordingly. Where appropriate, risk assessments would be carried out in accordance with Highways England’s Process for Managing Risk on the Strategic Network (GD04/12).
3.18 Other Relevant Factors
None have been identified in addition to the preceding sections.
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4. PLANNING FACTORS
4.1 Option Constraints
There are a number of potential constraints in relation to the Scheme; these will continue to be considered and addressed throughout the next stage of scheme development. These include the following:
• Land ownership for road widening - this may require compulsory purchase of land.
• Great Eastern Main Line - this rail line within 200m of the A12 between junctions 22 and 23, and junctions 24 and 25 which will require crossing for the A120 to tie into the A12
• Braintree Branch line – this rail line runs from Whitham to Braintree located in the west of the study area which may need crossing
• Bradwell Quarry located in the middle of study area
• The River Blackwater which runs through the study area
• Environmental constraints – preliminary environmental assessments have been undertaken, however these need updating and further quantification is required. As part of this process a full set of draft environmental mitigation measures and plans will be developed and consultation progressed with environmental groups.
• Emerging infrastructure – there is a need for co-ordination between improvements brought forward by Highways England and those progressed by local authorities in line with the SELEP objectives; local and strategic schemes must be phased appropriately.
• Emerging development in terms of allocated sites – this is reliant on the local authority local plan process, and the timescales for developing these.
4.2 Planning Policies
4.2.1 Local and Regional Planning Policies
The following policies provide context for the A120 Braintree to Marks Tey Transport Appraisal largely based on policies of Essex County Council and Braintree District Council. Essex County Council Policies
Essex County Council has produced various policy documents with implications for infrastructure development. A summary of the key policies follows: • Essex Transport Strategy: the Local Transport Plan for Essex (LTP3, June 2011) states that: “Our vision is for a transport system that supports sustainable economic growth and helps deliver the best quality of life for the residents of Essex”; • The Essex County Council (ECC) Key Corporate Outcomes Framework 2014-2018, states the commitment to providing sustainable economic growth for Essex communities and businesses, and delivering increased connectivity and journey time reliability on the Priority Route (PR1) Network, of which the A120 between Braintree and Marks Tey is a vital component; • The ECC Vision for Essex, July 2013-2017, pledges that ECC work tirelessly to keep Essex as an economic powerhouse ensuring more jobs are created and local businesses supported, and to achieve that ECC must develop and maintain the infrastructure that enables its residents to travel and businesses to grow;
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• The ECC Local Corporate Plan 2012-2017 highlights ECC’s desire to ensure the physical and technological infrastructure is in place to enable businesses to flourish; • The Greater Essex Integrated County Strategy, December 2010, states that growth based around the A120 will be an important characteristic of growth in the Haven Gateway sub-region.
The Essex Transport Strategy LTP3 identifies the following outcomes or objectives: • Provide connectivity for Essex communities and international gateways to support sustainable economic growth and regeneration; • Reduce carbon dioxide emissions and improve air quality through lifestyle changes, innovation and technology; • Improve safety on the transport network and enhance and promote a safe travelling environment; • Secure and maintain all transport assets to an appropriate standard and ensure that the network is available for use; • Provide sustainable access and travel choice for Essex residents to help create sustainable communities.
More specifically, the Essex Transport Strategy LTP3 goes on to identify key transport priorities of which the following are relevant to the A120 study: • Lobbying Government for enhancements to the A120 to access Harwich port and between the A12 and Braintree; • Dualling of A120 would provide essential network resilience for traffic accessing the Haven Ports by providing an alternative to the A12 and A14 in line with TEN-T ambitions to improve network efficiency; • Reducing the number of people killed or seriously injured on Essex roads; • Providing the transport improvements needed to accommodate housing and employment growth in a sustainable way in the Haven Gateway; • Improving the availability, reliability and punctuality of local bus services in the Haven Gateway; • Improving and promoting cycle networks; • Improving the availability of travel choices and awareness of them; • Improving transport access to Harwich to enable low carbon expansion of the port and wind port; • Minimising the impact transport has on the character of our rural areas. Braintree District Council Policies
The Braintree District Core Strategy (2011) is a document that outlines the vision for Braintree District. This vision is summarised in the document as follows:
“Our vision is that by 2026 a more sustainable future will have been secured for all the people and places in Braintree District and the natural environment will have been protected and enhanced. Braintree, Witham and Halstead will be thriving market towns with regenerated town centres and their historic character and green spaces protected. Most growth will have been provided in Braintree and Witham, including a new mixed use neighbourhood to the north-west of Braintree, comprising housing, employment and community uses and new neighbourhoods with housing and community facilities to the south-west and north-east of Witham. There will be a new business park close to the A120 at Great Notley. The key service villages of Coggeshall, Earls Colne, Hatfield Peverel, Kelvedon, Sible Hedingham and Silver End will have provided local housing, jobs and services for the adjoining rural areas. There will have been regeneration of former factory sites in Silver End and Sible Hedingham, which will have enhanced these villages.”
The Braintree Core Strategy also outlines a series of policy statements on various issues, with those potentially relevant to any upgrade of the A120 summarised as follows:
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• “To preserve and enhance the character of the rural heartland of the Braintree District, its countryside and villages, by supporting development that is needed to make settlements and the rural economy more sustainable and protect and enhance the natural environment.” • “Promoting Accessibility for All”, via - “The Council will work with partners to improve accessibility, to reduce congestion and reduce the impact of development upon climate change. - Future development will be provided in accessible locations to reduce the need to travel. - Sustainable travel will be encouraged through the requirement for travel plans from major developments, employers and institutions. - Sustainable transport links will be improved, including provision of and contributions for cycling and walking and quality bus partnership. - Traffic and car parking will be carefully managed to encourage sustainable travel. - The promotion of community based initiatives such as car pools, car sharing and voluntary mini- bus services will be encouraged.”
The Braintree District core strategy also comments on transport infrastructure issues and needs relevant to the A120 as follows: • Congestion relief at Galley’s Corner Roundabout to the east of Braintree. • Braintree-Marks Tey stretch of the A120 remains congested and unimproved, leading to significant congestion particularly in Braintree near to the Galley’s Corner Roundabout. • To support the District’s economy, the main road network (in particular the A12, A120 east of Braintree and A131 at Halstead) needs to be improved. • Reducing the percentage of people of working age who travel outside the District to work to below 2001 Census levels.
4.2.2 National Policies
The A120 forms part of the Strategic Road Network (SRN) managed by Highways England, which immediately implies the national importance of the corridor.
The A120 is also part of the Trans-European Strategic Network (TEN), which is comprised of routes defined by the European Union as being of significant importance to the economy and to promoting social cohesion. This highlights the importance of the route at the strategic national level in the international context.
According to the Department for Transport (DfT) Road Investment Strategy (RIS): for the period 2015/16 – 2019/20 Road Period , the SRN’s physical size and volume of use means that “it has a vital role to play in delivering government’s goals for our national transport network.” These goals are outlined in the National Network National Policy Statement (NN NPS) as follows: • Providing capacity and connectivity to support national and local economic activity. • Supporting and improving journey quality, reliability and safety. • Joining our communities and linking effectively to each other. • Supporting delivery of environmental goals and the move to a low carbon economy.
The DfT RIS has also targeted eight areas for improved performance in the short term as follows: • Making the network safer • Improving user satisfaction • Supporting the smooth flow of traffic • Encouraging economic growth
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• Delivering better environmental outcomes • Helping cyclists, walkers and other vulnerable users of the network • Achieving real efficiency • Keeping the network in good condition
4.3 Route to Consent It is assumed that the project will be a Nationally Significant Infrastructure Project (NSIP) requiring consent under the processes set out in the Planning Act 2008. Accordingly the application will be assessed against the National Networks National Policy Statement (NNNPS). For further discussion on the consenting regime, please refer to section 4.6 below.
The NNNPS recognises that there is a critical need to improve the national networks to address road congestion and crowding on the railways to provide safe, expeditious and resilient networks that better support social and economic activity; and to provide a transport network that is capable of stimulating and supporting economic growth. However, the Government’s policy on development of the Strategic Road Network is not that of predicting traffic growth and then providing for that growth regardless. Individual schemes will be brought forward to tackle specific issues, including those of safety, rather than to meet unconstrained traffic growth (i.e. ‘predict and provide’).
Paragraph 2.10 of the NNNPS indicates that the Government has concluded that at a strategic level there is a compelling need for development of the national networks – both as individual networks and as an integrated system. The guidance is therefore that the Examining Authority and the Secretary of State (SoS) should start their assessment of applications for infrastructure covered by the NNNPS on that basis.
The Government’s wider policy is to bring forward improvements and enhancements to the existing Strategic Road Network, and this will include improvements to trunk roads, in particular dualling of single carriageway strategic trunk roads and additional lanes on existing dual carriageways to increase capacity and to improve performance and resilience.
Applicants should also provide evidence that they have considered reasonable opportunities to deliver environmental and social benefits as part of schemes.
Subject to the detailed policies and protections in the NNNPS, and the legal constraints set out in the Planning Act, there is a presumption in favour of granting development consent for national networks NSIPs that fall within the need for infrastructure established in the NNNPS.
Detailed work will be needed to support any application in a wide range of areas. These include, but are not restricted to:
• An outline of the main alternatives studied by the applicant and an indication of the main reasons for the applicant’s choice, taking into account the environmental effects.
• An options appraisal.
• Consideration of design as an integral consideration from the outset of a proposal.
• Objective assessment of the impact of the proposed development on safety.
• Air Quality.
• Biodiversity and Ecological mitigation.
• Flood risk.
• The historic environment.
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• Landscape and visual impacts.
• Noise and vibration.
• Water quality and resources.
• Climate change resilience.
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5. DESCRIPTION OF ROUTE OPTIONS
5.1 Introduction
This Chapter provides a summary of the process used to develop route options for assessment; a description of each of the options taken forward to assessment; and a description of the options discarded and the reasons why. The Chapter also provides the engineering assessment of the options together with outturn scheme cost estimates for all the options.
Although the project is for an improvement scheme on a trunk road which is managed by Highways England, ECC is developing the scheme to a preferred option stage so that an application can be made for the scheme to enter Highways England’s Roads Investment Strategy Period 2 programme, therefore the scheme is following Highways England processes.
The figure below shows the stages of a major road project development.
Figure 3: Major Scheme Development Phases
ECC is undertaking the following stages 0, 1 and 2. Stage 0 is as per Stage 0 of the Department for Transport’s Transport Appraisal Process as detailed in the WebTAG guidance. Stages 1 and beyond form part of Highways England’s Project Control Framework (PCF).
Stage 0 comprises: • Definition of problems and objectives • Options generation • Options sifting • Development and assessment of potential options • Identification of better performing options
Stage 1 comprises: • Identify options to be taken to public consultation • Assess options in terms of environmental impact, traffic forecasts and economic benefits • Refine the cost estimate of options (including an allowance for risk)
Stage 2 comprises:
• Carry out public consultation including exhibitions • Analyse comments received and select a preferred option • Refine the cost estimate for preferred option (including allowance for risk) • Refine the environmental impact assessment, traffic forecasts, and economic benefits following public consultation if required • Produce an outline business case • Announce the preferred route
This report is being produced at Stage 1.
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5.2 Options generation phase (Stage 0) The options generation phase is described in detail in the Options Assessment Report (Document Ref: B3553T41-JAC-GEN-00-RP-C-002), issued April 2016. For ease of reference and to provide context for the detailed assessment of options, the process and outputs from Phase 0 are summarised below. In Stage 0 an initial long list of 68 options was generated, these were aggregated into 30 groups with a representative alignment identified for each group based on the physical and environmental constraints and appropriate horizontal geometry. An early sifting exercise was conducted on these 30 groups to review the strategic fit of these 30 groups with the overall project objectives (Table 1). This resulted in the dropping of 3 rail options leaving 27 highway options to be progressed for sifting
The 30 groups are shown in the figure below.
Figure 4: Aggregated options for sifting
Any solutions that clearly failed to meet the defined objectives, failed to alleviate identified problems or failed to meet key viability and acceptability criteria were then discarded. The methodology for achieving this was largely based on the Department for Transport’s Early Assessment and Sifting Tool (EAST) and the associated guidance. The criteria each group were assessed on were:
• Strategic fit o Scale of impact on identified problems o Fit with other project objectives • Economic case o Economic growth o Carbon emissions o Local environment o Well being o Expected value for money category
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• Managerial case o Public acceptability o Practical feasibility o Design safety • Financial case o Capital cost o Revenue cost o Overall cost risk
The scoring of these options is in figure 14 of the Options Assessment Report .
If options scored the lowest mark (1) in a category they were automatically discounted. For environmental impact this included options with significant adverse effect on high importance features for instance SSSIs, local/ county wildlife sites, ancient woodlands, scheduled ancient monuments, grade I or II* listed buildings. For design safety this included options likely to have significant departures from design standards that would leave residual safety problems which could not be mitigated.
General themes in the options discounted at this stage included:
• Options that joined the A12 at Marks Tey or north of Marks Tey were discounted on grounds of operational safety (the A12 in this section having a particularly poor safety record), difficulty of construction (proximity to railway line and lack of space between to accommodate junction slip roads) and environmental grounds (SSSI, listed church) .
• Options that commenced at Galley’s Corner and headed immediately south were rejected due to operational safety concerns over a junction on a tight bend
• Options that retained the existing Galley’s Corner and Marks Farm Roundabouts were rejected due to safety concerns as well as scoring lowly on in terms of strategic fit (not solving the congestion problems in this area)
• Significantly longer options (for instance northern bypass of Braintree) or options that would significantly increase total journey length (for instance joining A12 south of Witham) due to a combination of high costs and severe environmental impacts.
The outcome of this sifting process was the identification of the nine potential options which are shown in drawing B3553T41-JAC-GEN-00-DR-Z-0006 contained in Appendix A as well as in Figure 5.
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Figure 5: Shortlisted route alignments
In broad terms, these follow three corridors as described below:
Corridor Option Western starting Route Eastern starting point point
Northern 2 Galley’s Corner North of existing Between Kelvedon A120, entirely off-line and Marks Tey
17 River Brain North of existing Between Kelvedon A120, entirely off-line and Marks Tey
3 Galley’s Corner Part on-line or north Between Kelvedon of existing A120 and Marks Tey
Central 4a Galley’s Corner Outside northern Between Kelvedon edge of Bradwell and Marks Tey Quarry
4b Galley’s Corner Through Bradwell Between Kelvedon Quarry and Marks Tey
1b River Brain Through Bradwell Between Kelvedon
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Quarry and Marks Tey
1a River Brain Outside southern Between Kelvedon edge of Bradwell and Marks Tey Quarry
Southern 9a Galley’s Corner Outside southern South of Kelvedon edge of Bradwell Quarry
8 River Brain Outside southern South of Kelvedon edge of Bradwell Quarry
Table 33: Route options at end of Stage 0 sifting process
5.3 Initial option assessment (Stage 1)
At the beginning of Stage 1 a further evaluation was undertaken to reduce the number of options down to a manageable number to consider in more detail and potentially present for consultation. To reduce the number of options, three key questions had to be answered:
• Were there any remaining environmental “show stoppers” that would differentiate between route options?
• Were there any engineering feasibility or cost reasons why we cannot pass through Bradwell quarry?
• Were there any engineering feasibility or cost issues that would rule out route options starting in the vicinity of the River Brain or at Galley’s Corner?
In relation to the environmental question, no new “show stoppers” were found against any of the nine options. The overall level of environmental effects associated with each route option was broadly comparable and thus not a differentiating consideration at this stage. Of the nine options, Options 2 and 17 were consistently the worst performers in Value for Money Terms. Hence the decision was made to discard Options 2 and 17, noting that these options unlike the other northern option, Option 3, did not bring the benefits for some local traffic movements of connectivity with the existing A120.
In relation to the quarry question, discussions with ECC minerals team confirmed that the options passing through Bradwell quarry were feasible in principle. Cost would depend on the engineering detail and whilst likely to be significant would not be disproportionate to the overall cost of the scheme. The options avoiding the quarry had greater impact on existing settlements - in the case of option 1a Silver End and in the case of option 4a the southern limits of Bradwell and Perry Green. Option 4a also had an impact on the setting of the Grade 1 listed Parish Church of the Holy Trinity in Bradwell. Considering these factors the decision was made to discard options 1a and 4a.
In relation to the western starting point question, this would largely depend on development of options, including initial junction layouts, traffic analysis and other assessments and both starting at the River Brain or Galley’s Corner were options worthy of further investigation.
Thus five routes were selected to be developed in more detail and assessed, from north to south being 3, 4b, 1b, 9a and 8.
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Corridor Option Western starting Route Eastern starting point point
Northern 3 Galley’s Corner Part on-line or north Between Kelvedon of existing A120 and Marks Tey
Central 4b Galley’s Corner Through Bradwell Between Kelvedon Quarry and Marks Tey
1b River Brain Through Bradwell Between Kelvedon Quarry and Marks Tey
Southern 9a Galley’s Corner Outside southern South of Kelvedon edge of Bradwell Quarry
8 River Brain Outside southern South of Kelvedon edge of Bradwell Quarry
Table 34: Route options for detailed assessment
5.4 Design parameters and assumptions Introduction
The design of the options has been developed in accordance with DMRB and MCHW, some new standards have been issued during the design development period, refer to the Implementation of New Standards PCF product for details on the application and impact of these new standards (Document Reference: B3553T41- JAC-HGN-00-REP-C-0007). Many aspects of the design will not be developed until later on in the design process, therefore for costing and environmental assessment purposes some design assumptions are required which are summarised below.
Expressway
In Highways England’s Roads Investment Strategy the aspiration is stated for the A120 to become an Expressway. (Expressways will be high standard dual carriageways with limited junctions and technology to manage traffic, inform motorists and provide safety approaching motorways levels, with ease of maintenance and operational resilience at the heart of their design.) With this in mind, in so far as is relevant to this stage of project, the design provides for this.
At the time of writing the Expressway standards are developing but features are expected to include: • Highest quality geometry all-purpose trunk road (APTR) carriageway operating at the national speed limit (ie 70mph) and typically mile-a-minute average operational speed • Grade separated junctions or left only movements and no central reserve gaps • No direct private means of access/egress and limited junctions (generally B class roads and above) • Prohibition of non-motorised users (NMUs) and slow moving vehicles shall be prohibited from using an expressway and where practicable, alternative provision shall be considered so that NMUs journey experience should at a minimum, be no worse for any group than before the implementation of the scheme. • Emergency Refuge Areas (ERAs) spaced at 2.5km in each direction with Variable Message Signs (VMS) on cantilever gantries co-located at the ERAs • Proposed Central Reserve Concrete Barrier
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• CCTV cameras to provide comprehensive coverage and incident detection system • Boundary fencing required to be maintained by the Highway Authority • Radar Incident Detection and Automatic Signals
Many of these features above are matters for later stages in the design; the design that has been done, in particular the basic road layout, makes allowance for their future inclusion.
Highway Geometry
All options have been designed to the dual two lane all-purpose (D2AP) trunk road cross-section as defined in figure 4-3a of DMRB TD27/05 “Cross-sections and headroom”
Noting the requirement for a mile-a-minute average operational speed for an Expressway a design speed of 120B or above as per DMRB TD9/93 “Highway Link Design” has been targeted. The majority of mainline horizontal and vertical radii are all desirable minimum or within allowable relaxations, however some departures have been identified at this stage mainly as a result of existing network constraints. All departures are recorded in the Departures from Standard Checklist PCF product (Document Reference: B3553T41-JAC-HGN-00-REP-C-0006). In later design stages verge and central reserve widening will be added to provide the requisite sight distance, thus locally increasing the cross section of the road from that currently shown. In space critical locations, for instance Galley’s Corner, the design has allowed for this widening.
The horizontal alignment of the A120 mainline (within the general corridor of the route option) may vary at a later date as the result of consultation comments or further assessments. The vertical alignment of the mainline is likely to be varied as the design develops to optimise the earthworks balance or suit other requirements like drainage as further information becomes available.
Due to the provision of the ERAs in accordance with the draft expressway standards it is not expected for any other laybys or rest areas to be provided but the need will be assessed during later design stages. The need for maintenance hard / standings will be discussed with the maintainer (ASC) as the scheme develops.
No road safety audit has been carried out on the design as HD 19/15 does not require a Stage 1 Audit until the completion of preliminary design. The design has been discussed with the operational safety expert within the design team and indeed safety included in options assessment. For further details on operational and maintenance safety see section 8.1.
Junctions
Due to the programme restrictions on the scheme development, the traffic model and the highways design have been conducted concurrently. This means that the junction arrangements shown have been developed without the full traffic model and therefore are subject to change, so at this stage are indicative only. The design has been progressed far enough to confirm the general viability of a solution for a junction in so far as it effects the overall alignment of each option, inform the scheme cost estimate and the general environmental impact. The detail of junctions would be confirmed at later stages in the design process. This should be borne in mind when reading the option descriptions that follow. Side Roads, Non-Motorised Users and Accommodation Bridges
Side road and potential NMU diversion layouts have been developed but are indicative only; they have been designed to show what a workable solution could look like and allow for the same in the scheme costings. Whilst there have been informal discussions with Essex CC with regards to NMU provision, they are subject to change as the design detail is developed and the NMU context report is completed at PCF stage 2. All NMU bridges have been designed to double as accommodation bridges, a strategy which will be further reviewed as the design develops and during discussions with both the Essex County Council and affected landowners.
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Accommodation Works
Other than the provision of bridges above, there has been no consideration of accommodation works at this stage. This would be developed at the preliminary design stage in consultation with the affected landowners.
Drainage Design
Locations of potential outfalls and attenuation ponds have been developed and are shown on the scheme drawings (Appendix B) but the position of the ponds is subject to change as the design develops. Outfalls to watercourses have been assumed at this design stage as ground information / infiltration rates are not known and this assumption has been used to inform the vertical alignment design of the route options. At later stage of design in accordance with standards / SUDS guidance this would be revisited, including site tests, with a view to using infiltration drainage wherever possible.
At this design stage no access routes for maintenance to / from the ponds have been designed, this will be developed in future stages, the preference will being for access wherever possible off the local road network access. Major culvert locations have been shown based on the desk based study. Pollution control measures are not detailed at this stage, the requirements will be developed from the HAWRAT assessment and through discussions with the Environment Agency during later stages of the scheme development. Culverts and ponds have had initial sizings calculated based on 100 year return storms with climate change applied in accordance with EA Feb 2016 guidelines for Anglia region (assuming for essential infrastructure, 120 year design life) , this being 65% for watercourse flows in flood zone 2/3 and 35% and 40% on rainfall.
Lighting Design
At this stage on the A120 Braintree to A12 scheme no lighting assessment has been carried out. The lighting design will not be developed until the preliminary design stage (PCF stage 3), the assumption at this stage is that the junctions and the mainline alignment in the vicinity of the junction will be lit, but all other sections of the scheme will not be lit. Where possible, lighting will be located in the verges to remove the need for central reserve working.
Road Sign Design
At this design stage no sign design has been undertaken but it is considered possible that the new proposed junctions at the western end of the scheme and with the A12 may require some gantry mounted signage. At all other locations it is expected that verge mounted signs will be sufficient. Apart from the cantilever gantries required for the VMS on the mainline (co-located at the ERAs), no other mainline gantries are anticipated at this stage.
Road Restraint Design
To date no verge road restraint design has been developed, it is anticipated that standard steel verge road restraint will be provided where required by the RRRAP assessment. Some localised high containment barrier may be required at gantry locations, as well as a high containment parapet provided where the routes cross over the railway. As detailed in the expressway section a central reserve concrete barrier is expected to be provided.
Road Pavement Design
The design of the road pavement has not been developed at this stage but assumptions at this stage are that the pavement will be fully flexible or flexible-composite with a Thin Surface Course System as the surface course meaning the noise produced from the road will be lower than a concrete pavement or Hot Rolled Asphalt (HRA) with stone chippings.
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Proposed Structures
At this stage of the scheme there has been limited structures design. Where side road and accommodation bridges cross the proposed mainline A120 it has been assumed that where possible these will be provided without a pier in the central reserve to reduce maintenance requirements, in addition the preference will be for integral bridges to reduce the maintenance liabilities created by expansion joints and bearings.
Where structures are required over the River Blackwater, the extents of earthworks will be kept out of the flood plain to avoid the requirement for flood compensation and minimise effect on flows.
Geotechnical Design
At this stage limited geotechnical design has been developed and all side slopes have been designed with a 1 in 3 side slope. This is to promote long term stability of the geotechnical structures and to facilitate maintenance activities such as grass cutting. As the design develops there may be slight changes to the side slope to suit the on-site material, which would alter the footprint of the scheme.
Four of the five routes for assessment pass through Bradwell quarry requiring some ground treatment. The proposed approach is detailed in section 5.12.2.
Statutory Undertakers Requirements
All of the route options cross a large number of utilities, to date only C2 responses have been received and no C3 estimates or diversion design work has been undertaken so at this stage the extent of such diversions is not known. The identified clashes for each option have been priced using rates from historical schemes, this information is provided in the Statutory Undertakers Estimate PCF product (Document Reference: B3553T41- JAC-HGN-00-REP-C-0005)
Construction Impacts
The A120 to A12 scheme will be a significant construction project requiring a large construction compound or possibly the use of additional satellite compounds. At this stage of the project no consideration has been given to site compound location or the haul routes that will be used during construction. The constructability assessment is contained in section 5.12.8.
5.5 Other schemes
Millennium Way Slip Roads
As mentioned in section 2.4, separate to the A120 Braintree to A12 scheme, west facing slip roads off / onto the A120 are being proposed at B1018 Millennium Way to provide short-term congestion relief to Galley’s Corner. At the time of writing this scheme has not secured funding nor planning consent so it is not certain that it will proceed and so it is not included in the base case for the A120 Braintree to A12 scheme. For some of the A120 options, where noted in the following sections, these proposals would be necessary and if they did not proceed separately would instead be provided under the A120 Braintree to A12 scheme.
A12 Junction 19-25 Widening
As part of Roads Investment Strategy it is proposed that the A12 be widened to three lanes in each direction between Chelmsford (J19) and Marks Tey (J25). This scheme is being developed at the same time as the A120 by Jacobs for Highways England. It is planned that the route option public consultation for the A12 will be held at the same time as the A120 Braintree to A12 one.
The A12 project have considered a range of widening solutions, in the sections of the potential A120 tie-ins. The two options which will be presented for consultation are:
• Asymmetric on-line widening – the A12 would be widened to the east. The existing southbound carriageway would be widened and become the new northbound carriageway, with a new southbound
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carriageway constructed to the east. The existing northbound A12 carriageway would be converted into a local access road (LAR).
• Off-line widening – a new dual three lane A12 would be constructed off-line in the land to the east of the existing A12 in two sections between J22 and J23 as well as between J24 to J25, outside of these sections the widening will be carried out on-line. The new A12 would vary between 125 to 250m to the east of the existing. In these off-line widening locations the existing A12 would be retained as a LAR, with the carriageways reconfigured – the detail of which to be confirmed.
With both options above, the existing A12 Kelvedon bypass would be widened on-line to three-lanes in each direction. The A120 scheme will therefore tie into a widened A12, however it is not known at this stage whether this widening will be online or offline.
5.6 Option 3 The alignment of option 3 is shown in overview on B3553T41-JAC-GEN-00-DR-Z-0008 in Appendix A and in detail on plan and profile drawings (B3553T41-JAC-HML-00-DR-C-0301 to 0306) in Appendix B.
Option 3 would commence west of Millennium Way with additional west facing slip roads provided to link to the B1018 as per section 5.5, above. The existing B1018 would be signalised to allow S/B traffic on the B1018 to join the A120 W/B.
Option 3 would remove the existing Galley’s Corner roundabout with the A120 passing through the site of the existing roundabout at grade, curving northward. A new grade separated junction would be provided around 750m north east of the existing roundabout, giving access to Marks Farm roundabout, the A131 north, Fowler’s Farm roundabout and the B1018. It is envisaged that this junction would be of the “dumb-bell” layout, although this is subject to review once further traffic flows information becomes available
A new dual carriageway link around 500m long would run north-westward from the new A120 junction to join the existing A120 around 900m south of Marks Farm Roundabout, thus providing the connection from the A120 to the A131 north. Due to the large movement of vehicles from the A120 heading north on the A131, it is likely that a segregated left turn will be provided at the northern dumb-bell roundabout for this traffic.
Local roads would be realigned to suit either side of the new A120 with a separate bridge envisaged to provide a link into Braintree from Ashes Road via Cressing Road. The existing link from Fowler’s Farm Roundabout to Galley’s Corner Roundabout would be realigned and extended eastward to meet this bridge at a proposed roundabout south of the proposed A120. Links from this roundabout to the southern dumb-bell roundabout of the A120 junction and provide the route into Braintree from the A120 to the east, as well as to Cressing via Long Green Road. The existing pedestrian underpass west of the existing roundabout would be retained.
Due to the spatial constraints (properties and businesses surrounding the existing roundabout) and safety requirements in standards with regard to horizontal and vertical alignment and stopping sight distance near junctions it would not be possible to locate the new junction nearer the existing Galley’s Corner Roundabout. An underpass for the A120 at Galley’s Corner Roundabout was initially considered to allow local roads to be directly taken over the A120 but such a layout would have required departures from standard in vertical curvature and stopping sight distance of two steps below desirable minimum values on the approach to a junction. Due to safety concerns over such geometry and anticipated difficult construction and complex traffic management phasing this option was rejected. By placing the A120 in an underpass in this section it would also have been likely to require a pumped drainage system, creating an increased ongoing maintenance liability.
After the new Galley’s Corner Junction, the route continues north-eastward, passing under the existing A120 to the west of the Dolphin Public House. The route then loops around, bypassing Bradwell to the north, passing to the north of Miles Farm and crossing the River Blackwater north of the Shelbourn Bridge; this location for the crossing being chosen on environmental grounds, the River Blackwater Valley being a local wildlife site closer to the village. The river valley would be crossed on a viaduct approximately 190m long, it being envisaged that this would span the entire width of the river floodplain. Water Lane would pass under the viaduct, possibly re- aligned to avoid the proposed bridge piers.
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After crossing the River Blackwater the route continues to curve southward to join the existing A120 alignment near Doghouse Road and the access road to Bradwell Quarry. A grade separated junction would be provided in this area to facilitate access to and from Bradwell and to and from the west of Coggeshall. The layout here is complicated by the proximity of the existing A120 and other local roads and trying to minimise diversions for non-motorised users (NMUs). The envisaged layout essentially is of the “dumb-bell“ type with the eastbound slips connecting to a roundabout to the north of the proposed A120 joining a realigned Doghouse Road which passes under a bridge carrying the new A120.The realigned Doghouse Road, which would have an adjacent NMU facility (to replace a footpath severed by the A120) would then join the existing A120 at another roundabout. The westbound off slip would pass over Doghouse Road to connect to another roundabout to the west on the existing A120 – the angle of the various roads and lack of space preventing it tie-ing in directly to the roundabout at the junction with Doghouse Road. The westbound on slip would lead up to the new A120 from this third roundabout. Between the two roundabouts on the existing A120 there would be a junction with the access road from Bradwell Quarry.
The proposed A120 would then cross over the existing A120 to the east of Whiteshill Farm and then follows the existing A120 on a similar alignment but further south. A separate new local access road (LAR) would be provided to the south of the proposed A120 to link West Street in Coggeshall to Bradwell for local traffic and a parallel path provided for non-motorised uses (NMUs). The existing A120 carriageway, on the north side of the new A120, would be used as an access road to Stock Street Farm and adjoining properties. Holfied Grange Road (a single track lane) would join this access road which then would cross over the new A120 on a bridge to join West Street. The arrangement outlined would give the most direct route for the LAR and NMUs between Bradwell and Coggeshall, avoiding the LAR having to bridge over the new A120. Should this route option be selected as the preferred route, the arrangement of local roads and accesses in this area would be considered further in discussion with the residents and local communities.
The proposed A120 would then join the existing single-carriageway Coggeshall bypass which would be widened. It is anticipated that widening would generally be on the north side (away from Coggeshall) with the existing A120 carriageway used as the westbound carriageway and a new carriageway provided for the eastbound traffic. Due to the tight curvature of the existing A120 and to limit the number of junctions on the new A120 in line with the Expressway concept it would not be proposed to provide a junction at the start of the Coggeshall Bypass, access to the new A120 from the west of Coggeshall being provided instead by the junction at Doghouse Road and the LAR as above. The existing junction with Ambridge Road (a single track lane) would be closed, with Ambridge Road diverted south-westward to join the bridge provided over the A120 for Stockstreet Farm access/Holfield Grange Road.
The existing at-grade junction at B1024 Colne Road would be replaced with a grade separated junction. There are spatial constraints at this junction – houses north of the existing A120, a distribution centre to the south-east of the junction and the playing fields of Honywood Community Science School to the south-west. Consideration was given to closing the junction, however it is relatively well used and doing this would likely lead to more traffic elsewhere in Coggeshall. Furthermore, the section of Colne Road south of the distribution centre has a weight restriction so closing the junction would mean relocation of the distribution business and significant compensation. Due to the spatial constraints it would not be possible to accommodate a full grade separated junction to TD22/06 “Layout of Grade Separated Junctions”. Instead it is envisaged a compact grade separated junction to TD40/94 “Layout of Compact Grade Separated Junctions” would be provided. Adopting this standard, in particular the geometry allowed in the compact connector roads, would allow a junction to be accommodated here. The anticipated traffic flows are in the range for such a junction, which will be reviewed following the receipt of further traffic flows. If this option was selected as the preferred route the junction layout here would particularly be given further consideration to ensure an optimal solution balancing environmental, traffic and safety factors.
It is proposed that the existing junction between the A120 and Tey Road, a single track lane, would be closed. Should this route option be selected as the preferred route, the access arrangements for the single farm along it would be discussed, options including providing a new private means of access parallel to the new A120 to link to Colchester Road.
Following Tey Road, the new A120 alignment would move off-line to the east of the existing A120 and head south-east, crossing the existing A120 at the beginning of the Coggeshall bypass with a grade separated
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junction provided to give access to the Colchester Road and Coggeshall and the existing A120. Due to the position of properties in this area it is envisaged that the junction would be located south of the existing A120 with a looped arrangement for the eastbound off and westbound on slips with Colchester Road realigned to suit.
Following the Colchester Road junction, the route would continue south-eastward toward the A12. Old Road would be realigned with a bridge provided over the new A120 and Mill Lane realigned as well. A bridge would be provided to carry Elm Lane over the new A120. After this the new A120 alignment would rise to bridge over the Great Eastern Mainline Railway (GEML)
A new, additional, grade separated junction (A12 Junction 24a) would be provided for the A120 junction with the A12, between the existing Junction 24 (Kelvedon) and Junction 25 (Marks Tey), just south of the Domsey Brook. The positioning of this junction would be to suit the proposed widening arrangement of the A12 in this area (see section 5.5). The layout assumed for such junction is a “dumb-bell” layout – this could be revised if required to traffic figures later in the design process, for instance a “trumpet” arrangement.
The Option 3 route is approximately 14km long, of which approximately 5km is on-line or adjacent to the existing A120. Along the route, in addition to the bridges outlined for local roads there would be further bridges for public right of way crossings. At this stage it has been assumed such bridges could also serve as accommodation access crossings for severed landholdings.
The design speed for Option 3 has been calculated in accordance with TD9/93 as being 120B, thus meeting the set target.
5.7 Option 4b The alignment of option 4b is shown in overview on B3553T41-JAC-GEN-00-DR-Z-0008 in Appendix A and in detail on plan and profile drawings (B3553T41-JAC-HML-00-DR-C-9401 to 9405) in Appendix B.
Option 4b commences west of Millennium Way with additional west facing slip roads provided to link to the B1018. The existing Galley’s Corner roundabout would be removed (save the existing pedestrian underpass) and a new grade separated junction and local roads provided similar to Option 3, as described in section 5.6.
Following the new Galley’s Corner junction the route then heads south-eastward, passing between Lanham Wood (designated Ancient Woodland) and Glazenwood Park, with Fells Farm Road realigned on a bridge over the new A120. The route then continues in the same direction passing to the north of Links Wood (designated Ancient Woodland) and then towards Bradwell Quarry, with Links Road and Sheepcotes Lane (both single track lanes) being realigned on bridges over the new A120.
The route then enters the area of Bradwell Quarry, passing to the south of the existing processing plant and over the access road to the proposed Rivenhall Integrated Waste Management Facility (IWMF) and then north of the large lagoon proposed as part of the IWMF proposals. The route then travels through the areas of future quarry extraction (referred to as areas A3, A4 and A7 in the Essex County Minerals Plan), passing to the north of Pantling’s Lane.
Now descending toward the River Blackwater, the route passes under the B1024 Coggeshall Road south of Halfway Cottages. The route crosses the River Blackwater, north of Coggeshall Hall on a viaduct approximately 225m long, it being envisaged the viaduct will span across the entire width of the flood plain. The location of the crossing point of the river is dictated by environmental constraints (Priority Habitat areas to the south and to the north).
The route then bears north-eastward climbing out of the river valley. Coggeshall Road (Feering) is realigned and passes on a bridge over the new A120. The route passes Langley Green to the north, with Old Road realigned on a bridge over the new A120, and then curves south-eastward toward the A12. Elm Lane would be realigned on a bridge over the new A120 then the route begins to climb up on embankment to a bridge over the Great Eastern Mainline Railway (GEML).
A new, additional, grade separated junction (A12 Junction 24a) would be provided for the A120 junction with the A12, between the existing Junction 24 (Kelvedon) and Junction 25 (Marks Tey), similar to Option 3.
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The Option 4b route is approximately 13km long .The route is off-line construction with the exception of the tie- in works at the junctions at either end.
Along the route, in addition to the bridges outlined for local roads there would be further bridges for public right of way crossings. At this stage it has been assumed such bridges could also serve as accommodation access crossings for severed landholdings.
The design speed for Option 4b has been calculated in accordance with TD9/93 as being 120B, thus meeting the set target.
5.8 Option 1b The alignment of option 1b is shown in overview on B3553T41-JAC-GEN-00-DR-Z-0008 in Appendix A and in detail on plan and profile drawings (B3553T41-JAC-HML-00-DR-C-9101 to 9106) in Appendix B.
Option 1b commences on the A120 Braintree Southern Bypass, leaving the existing A120 alignment to the east of Notley Road bridge.
Access to and from Galley’s Corner Roundabout would be maintained from the new A120 via a limited movement grade separated junction with west facing off / on sliproads. The proximity, around 1km, to the preceding junction on the A120 to the west, the sliproads at London Road and the pinch point of the existing Braintree Branch Line overbridge on the A120 are factors affecting this new junction. It would not be possible for the new junction to be moved east due to the need for the link to the existing A120 having to pass under the existing railway bridge. Conversely, in order to maximise the weaving length between junctions, the junction needs to be as far east as possible. In order to maximise the weaving length in the westbound direction it is envisaged that a 270 degree loop arrangement would be used on the westbound link from the existing A120 so as to position the merge as far east as possible. Depending on the final road layout to be developed at later design stages the weaving length may be marginally less than the 1km required by standards and departures from standards required.
The route then passes over the River Brain, at this stage envisaged to be on a bridge to avoid impact on floodplain, and then under the Braintree Branch Line railway. Whilst a crossing under the railway would be more complex to construct, the topography, with the railway line being on the side of the river valley means that were the route to go over the railway the height of the embankment would be excessive with extremely large fill requirement and very significant adverse environmental effect. The route then heads east in a cutting, climbing out of the river valley, passing through the gap in development between the southern edge of Braintree (industrial areas and electricity distribution centre) and the northern limit of Tye Green. The B1018 Braintree Road would be realigned to the east and pass over the new A120 on a bridge.
A new grade separated junction would be provided to the north of Tye Green, with connections to the realigned B1018 and hence Fowler’s Farm roundabout and the existing A120 and A131 to the north. At this stage a dumb-bell arrangement is envisaged for this junction, with a segregated left turn proposed for A131 northbound traffic from the eastbound A120. The connection to the existing A120/A131 to the north would be through a new 1.3km long dual carriageway link road that bypasses Galley’s Corner to the east, allowing traffic to head to Marks Farm roundabout and on to the A131; this new link being necessary from a capacity point of view to carry the significant traffic flows between the A120 and the A131 north and relieve pressure on the existing Galley’s Corner roundabout. The link would pass over Ashes Road then curving around to join the existing A120 at a new roundabout approximately 850m south of the existing Marks Farm Roundabout.
The route passes to the north of Cressing, crossing Ashes Road north of the Almshouses. Ashes Road would be realigned to the west to pass over the new A120. The route then curves southward and descends into a cutting, crossing Lanham Green Road at its junction with Boars Tye Road. Lanham Green Road would cross over the new A120 on a bridge with Boars Tye Road realigned so that the junction with Lanham Green Road is south of the new A120.
The route then curves again to head east, passing Links Wood (designated Ancient Woodland) to the south with Links Road realigned on a bridge over the new A120. The route continues east passing around 700m north of Silver End with Sheepcotes Lane realigned on a bridge over the new A120.
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The route then enters the area of Bradwell Quarry and joins the route to the A12 as per Option 4b with the same alignment, junctions and local roads, as described above in section 5.7.
The Option 1b route is approximately 15km long. The route is off-line construction with the exception of the tie- in works at the junctions at either end.
Along the route, in addition to the bridges outlined for local roads there would be further bridges for public right of way crossings. At this stage it has been assumed such bridges could also serve as accommodation access crossings for severed landholdings.
The design speed for Option 1b has been calculated in accordance with TD9/93 as being 120B, thus meeting the set target.
5.9 Option 9a The alignment of option 9a is shown in overview on the plans in B3553T41-JAC-GEN-00-DR-Z-0008 in Appendix A and in detail on plan and profile drawings (B3553T41-JAC-HML-00-DR-C-9901 to 9904) in Appendix B.
Option 9a commences west of Millennium Way as per Option 4b, with the same route alignment, junctions and local roads until after passing Links Wood, west of Bradwell Quarry. Here the route turns south-eastward, with Sheepcotes Lane realigned on a bridge over the new A120. The route then runs through the south-western extents of the existing Bradwell quarry and southern future extension (referred to as area A5 in the Essex County Minerals Plan). Adjacent to the south-east of the extended Bradwell quarry is another area of potential mineral extraction (not in the current minerals plan, however), Parkgate Farm, which the route would also pass through.
The route continues south-eastward running through open countryside toward the A12, with Park Gate Road being realigned on a bridge over the new A120. The route rises to cross on a bridge over the GEML to join the A12 at a re-built Kelvedon South Junction (J23). The positioning of this junction would be to suit the proposed widening arrangement of the A12 in this area (see section 5.5). The layout assumed for such junction is a “dumb-bell” layout with a link from the western dumb-bell roundabout providing access to/from the A12 for Kelvedon.
The route is approximately 9.5km long. The route is off-line construction with the exception of the tie-in works at the junctions at either end.
Along the route, in addition to the bridges outlined for local roads there would be further bridges for public right of way crossings. At this stage it has been assumed such bridges could also serve as accommodation access crossings for severed landholdings. The design speed for Option 9a has been calculated in accordance with TD9/93 as being 120B, thus meeting the set target.
5.10 Option 8 The alignment of option 8 is shown in overview on the plans in B3553T41-JAC-GEN-00-DR-Z-0008 in Appendix A and in detail on plan and profile drawings (B3553T41-JAC-HML-00-DR-C-0801 to 0804) in Appendix B.
Option 8 commences on the A120 Braintree Southern Bypass as per Option 1b, with the route and junctions following the same alignments until the north of Silver End. The route then turns south-eastward, joining the route of Option 9a with the same alignment, junctions and local roads.
This route is approximately 11km long. The route is off-line construction with the exception of the tie-in works at the junctions at either end. Along the route, in addition to the bridges outlined for local roads there would be further bridges for public right of way crossings. At this stage it has been assumed such bridges could also serve as accommodation access crossings for severed landholdings.
The design speed for Option 8 has been calculated in accordance with TD9/93 as being 120B, thus meeting the set target.
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5.11 Scheme Costs The costs of the options that have been considered during Stage 1 are detailed in the Options Estimate PCF product (Document Ref: B3553T41-JAC-HGN-00-RP-C-0001). As well as estimating the works costs of each option it has also been necessary to estimate the preparation costs, land costs and supervision costs. All of the options have a 44% optimism bias factor applied to them at this stage. Additionally, works outside the existing highway boundary will be liable for VAT. As the great majority of the each scheme (including the part “on-line” option, option 3) are outside the existing boundary for simplicity at this stage VAT has been applied to the whole cost, which is a slightly conservative assumption.
Option 1B Option 3 Option 4B Option 8 Option 9 £ £ £ £ £
Highway Works (Incl. 441,822,580 320,203,540 390,389,271 302,284,603 252,279,936 Services diversion)
Project / Design Team Fees 35,345,806 25,616,283 31,231,142 24,182,768 20,182,395
(Contract Management and Supervision)
Other Development / Project Costs Land Acquisition costs, Part 1 44,182,258 32,020,354 39,038,927 30,228,460 25,227,994 Claims
Other Development / Project Costs
Legal support (DCO process), Employer’s Costs, Network Rail 51,301,411 42,525,443 42,372,247 39,236,331 30,485,747 Possession Cost and Environmental mitigation
Sub-total 572,652,055 420,365,620 503,031,587 395,932,162 328,176,072
Risks Optimism Bias @ 251,966,904 184,960,873 221,333,898 174,210,151 144,397,472 44%
Subtotal (1Q2016) 824,618,960 605,326,493 724,365,485 570,142,313 472,573,544
Inflation (from 1st Qtr 16 to 321,601,394 236,077,332 282,502,539 222,355,502 184,303,682 mid construction 3rd Qtr 24)
Sub-total (excl. VAT) 1,146,220,353 841,403,825 1,006,868,024 792,497,815 656,877,226
VAT @ 20% 229,244,071 168,280,765 201,373,605 158,499,563 131,375,445
Total (incl. VAT) 1,375,464,424 1,009,684,590 1,208,241,629 950,997,378 788,252,671
Table 35: Options Cost Estimate
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Option 1B is the most expensive option due to a combination of the option length, the remediation required through Bradwell Quarry and the cost of the Galleys Corner Bypass. Option 4B is the second most expensive option due to the remediation required through Bradwell Quarry, despite being a shorter option than Option 3. It is cheaper than Option 1B due to the simpler junction arrangements at the Braintree end. Option 3 is the median cost option as although it is longer than Option 4B with 3 intermediate junctions it does not cross Bradwell Quarry and therefore does not incur any remediation costs associated with crossing the Quarry. Option 8 is the second cheapest option as the southern options are considerably shorter than the central and northern options, although there are still significant costs associated with remediation of Bradwell Quarry. Option 9 is the cheapest and shortest option, however there are significant costs required for the remediation of Bradwell Quarry; it being cheaper than Option 8 due to simpler junction arrangements at the Braintree end.
Options 8 and 9 could also have the benefit of sharing the costs of A12 J23 with the A12 scheme as this is a shared A120 / A12 junction, however due to uncertainty as to the proposals of the A12 widening scheme, which are dependent on consultation, for now (in accordance with DfT WebTAG guidance) it has been assumed the full cost of a re-built J23 will be borne by the A120 scheme.
5.12 Engineering Assessment
5.12.1 Geometric Provision
The design speed for all options was calculated using DMRB TD 9/93 “Highway Link Design” by taking into account the alignment constraint and the layout constraint. The design speed of all options has been assessed 120B, meaning it is compatible the Expressway objective for achieving journey times of 1 mile per minute.
The departures identified at this stage are included in the Departures from Standards Checklist PCF product (Document Ref: B3553T41-JAC-HGN-00-REP-C-0006).
Options 1B & 8 do not have any mainline departures identified at this stage. Options 4B and 9B only have one identified departure associated with the existing vertical A120 vertical alignment on the approach to the Galleys Corner Junction. Option 3 is the option with the most departures, due to the constraint of the existing A120 geometry in the online sections, principally the existing single-carriageway Coggeshall Bypass which is being widened – which would have been designed for a lower design speed, likely 100kph.
Some of the departures identified at this stage may be able to be designed out as the design is developed. Departures are considered further in the Operational Road Safety section, section 8.1.
5.12.2 Geotechnical issues
Engineering Properties
Any alluvium found adjacent to water courses is likely to have a CBR of between 1% and 3% which would result in a capping layer being required for the road. Any alluvium excavated is unlikely to suitable for engineering fill. In addition settlement in these areas is likely to present an engineering challenge and ground improvement may be required, prior to road construction.
The Kesgrave formation found is likely to have a CBR value of around 10% which would not require any capping for the road foundation and the material will be suitable for use as engineering fill. If the road is in cut in this location then the material is likely to be able to support 1:2 slopes at a minimum.
The Lowestoft formation is likely to have a CBR of around 3% which could support a foundation without capping although a capping layer could be used to decrease the sub-base thickness, it is likely the material can be used as engineering fill. Any large embankments on the Lowestoft formation will require settlement checks and ground improvement or surcharging may be required prior to road construction. Cuttings in the Lowestoft formation could support a 1:3 slope.
London Clay typically has a CBR of just over 2% which would require a capping layer beneath the sub-base. Cuttings in London Clay could support a 1:3.5 slope and the material could be used as general fill. Large
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embankments will require settlement checks and surcharging or early construction may be required during the construction phase.
Bradwell Quarry and Park Gate Farm
Bradwell Quarry is a sand and gravel quarry located in the middle of the A120 Braintree to A12 study area operated by Blackwater Aggregates. All the route options with the exception of Option 3 impinge into the quarry site, to varying degrees.
Adjacent to the south-east of Bradwell Quarry is a further area of potential mineral extraction, Park Gate Farm with mineral options owned by Hanson Aggregates. This site is not in the minerals plan, however planning policy requires that development proposals do not sterilise mineral reserves so the treatment of this area also needs to be considered. Route options 8 and 9a would traverse the Park Gate Farm site.
The Bradwell Quarry site is capable of producing 1M tonnes of sand and gravel a year. Within the Essex County Council Minerals Local Plan (2014) there are 5 separate sites in Bradwell Quarry, Areas A3 – A5 are classified as preferred sites and areas A6 & A7 are designed as reserve sites that are likely to only be granted permission if the land bank in Essex falls below 7 years, areas A3 & A4 have already been granted planning permission. An indicative programme of extraction based on information available in the Essex minerals plan is given in the table below. Quarry Start Section Yield (mt) Years Date End Date A3 1 1 2016 2017 A4 3 3 2017 2020 A5 3 3 2020 2023 A6 2.5 2.5 2023 2025.5 A7 6.5 6.5 2025.5 2032
Table 36: Bradwell Quarry Excavation Timeline
The A120 is expected to start construction in 2023 and therefore areas A3 – A5 would be mined and restored with areas A6 and A7 still to be extracted.
It should be noted that the approved restoration proposals for the quarry by the quarry operator are based on a low level restoration, with no import of material being required with the set-aside overburden re-graded across the site. The quarry restoration methodology is to re-grade the stored overburden, however this material will be placed without compaction which will result in a material unsuitable for road construction due to the presence of soft patches. During this initial design stage a number of solutions have been investigated, however there is no available ground investigation data. One solution which represents a worst case solution is to remove all this overburden down to London Clay level and then compact the overburden in layers up to road construction level providing a suitable base for construction, this is the method that has been used for pricing purposes in Stage 1.
The ground improvement detailed above is for areas which will have been excavated and restored by the time A120 construction starts. For future quarry areas which includes areas A6 and A7 for options 1B & 4B and Park Gate Farm for options 8 and 9 it is assumed following discussions with ECC that the planning permission for these future areas are likely to be combined with the A120 Development Consent Order (DCO). Therefore planning restrictions could be placed on the mineral extractor to prevent un-compacted restoration. For pricing purposes in these future areas it has been assumed that the quarry operator will excavate and store the overburden for the A120 contractor to use, therefore removing the excavation costs. For further details on pricing refer to the Options Estimate PCF product (Document Ref: B3553T41-JAC-HGN-00-RP-C-0001)
Although for pricing purposes it has been assumed that remediation will involve removal and re-compaction alternatives will be assessed at later design stages, for example dynamic compaction or surcharging which it is anticipated could lead to substantial cost savings. Thus a conservative basis has been used for the pricing at this stage.
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5.12.3 Drainage and surface water runoff
The envisaged positive drainage system, surface water channels and pipes for ease of maintenance. Ponds provided at every mainline outfall to provide attenuation and treatment. Given the uncertainty over the existing drainage (where appropriate) and noting the greatly increased recent requirements for climate change it has been assumed for all options, regardless of whether on-line or not, for pricing that a complete new carriageway drainage system will be needed.
At this stage in absence of ground investigation data it has been assumed that positive outfalls to watercourses are provided and ponds sized on this basis, assuming no infiltration. This can be revisited as more ground data, including soakage tests are carried out at later design stages. This is thus a conservative assumption and gives the worst case for sizing of attenuation facilities. At this stage preliminary sizing of ponds do not indicate there should be any difficulty in complying with requirements for attenuation of flow (100 year storm plus climate change)
The options are broadly similar in terms of drainage and surface water runoff. The following paragraphs describe the principal areas of difference.
Options 1b and 4b run a long distance through the centre of Bradwell quarry. Due to the ground contours and re-profiling there is a lack of suitable outfalls in this section on the line of the route; the design has assumed outfalls to the nearest watercourses to the route, these being several hundred metres away with the vertical alignment of the mainline fixed to allow sufficient fall to these. If these outfalls were not provided there would be no outfall on the mainline carriageway between the quarry access road crossing and the River Blackwater, a distance of approximately 4km, which is considered excessive. Noting the interrelationship between the vertical alignment of the mainline and the earthworks solution for the quarry as above (where a lower alignment is better), the drainage in this section would be reviewed should one of these options be selected to help produce an optimal overall solution.
For Option 3, if selected, details of the existing Coggeshall bypass drainage would need to be obtained. It has been envisaged that in widening the Coggeshall bypass new attenuation and treatment ponds would be provided as none appear present in the existing situation. The near on-line section of Option 3 between Bradwell and the start of Coggeshall bypass will need careful consideration, in particular clearances above the watercourses crossing the route in this section, noting increased culvert sizes over existing (presumed, no details are known) somewhat conflicting with desire to keep levels as close to the existing due to buildability reasons.
For options 8 and 9b in their eastern sections between Park Gate Road and the A12 there is a lack of watercourses directly traversed by the route. There are watercourses some distance away to the south or examination of contours and detailed aerial photography indicates likely presence of them.
In short, none of the above amounts to a key discriminator between options and it is anticipated that for all options with further investigations and development of design a suitable drainage solution would be provided complying with the requirements of standards.
5.12.4 Statutory Undertaker’s Plant
A summary of the impacts of each option on Statutory Undertaker’s Plant is given below. For further details refer to the Statutory Undertakers Estimate PCF product (Doc Ref: B3555T41-JAC-HGN-00-REP-C-0005). Option 1b
The loop proposed for traffic merging onto the A120 W/B travelling from Galleys Corner impacts on some overhead HV cables, water mains and gas mains. This option then travels very close to the Braintree sub- station resulting in a required diversion of some overhead pylons in addition to a high pressure gas main. There are also some anticipated clashes with HV underground cables and a water main where the Galleys Corner Bypass ties back into the existing A120. The diversion of Ashes Road over the proposed A120 also impacts on the existing overhead HV cables. East of Ashes road the required diversions of LV cables, BT plant and water
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mains generally occurs at side roads. Additionally there may be some affected utilities where the proposed A120 ties into the A12.
Option 3
The existing Galleys Corner roundabout has a large number utilities which will be affected by the proposed option including; Water Mains, BT cables, Gas Mains and HV underground cables. There are also some likely diversions required as part of the Millennium Ways Slips scheme. After Galleys Corner the majority of the clashes are at side roads or the proposed junctions. In the online sections of the scheme the plant in the existing A120 verges which includes water mains and BT cables is likely to create some potentially long (c.2.5km) diversions. This option should avoid any impact on the Overhead 132kV system in the study area. The tie in location to the A12 is the same as Option 1B
Option 4b
Option 4B starts at Galleys Corner and therefore has the same significant impact on statutory undertaker’s plant as Option 3 at the beginning of the option. After the Galleys Corner junction the majority of clashes are located at side roads before the possible clashes at the A12 tie in. This option is not expected to impact on any 132kV overhead cables.
Option 8
This option has the same starting point as option 1B and therefore has the same clashes associated with the Loop and the tie into the existing A120, south of Marks Farm. This option also has the same significant impact on overhead HV cables associated with Braintree Sub-Station. After the River Brain Junction the route travels to the east of Silver end before tying into the A12 at a re-modelled J23. The majority of clashes encountered away from the junctions are at diverted side roads. There may be some affected BT, National Grid and Virgin Media plant at the J23 tie in depending on the exact arrangement of the junction and the proposed structures in this location.
Option 9b
Option 9B is a combination of Option 4B and 8, therefore has the significant impact on statutory undertakers plant at Galleys Corner. After Galleys Corner the majority of the clashes are located at side road diversions as well the possible impact on BT, National Grid and Virgin Media plant at the J23 tie in. This option is not expected to impact on any 132kV overhead cables.
Summary
In summary the River Brain options are expected to have a larger impact on statutory undertakers plant than the Galleys Corner options, however all options are likely to require significant diversions or protection measures at the western end of the scheme.
5.12.5 Existing Structures
The existing structures in all options can be cross-referenced with the Plan and Profile drawings found in Appendix B. Further tabulated structure details can also be found in Appendices D and E.
Existing Structures on the A120 which would be affected by the proposed options include:
• Twain Culvert – the 46 m long precast reinforced concrete box which crosses the River Brain is likely to be affected in Options 1B and 8. The structure’s embankments may need to be steepened locally.
• Galleys Corner Subway – A 34 m long cast in situ reinforced concrete box which is likely to require extending for Options 3, 4B and 9. The structure may also require strengthening pending the outcome of an assessment.
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• Tilkey Culvert – The 48 m long precast reinforced concrete box culvert crosses Robin’s Brook under the Coggeshall Bypass. The structure will likely either require extending or have its embankment’s steepened and possibly strengthened locally as part of Option 3.
• Tilkey Subway – A 17 m long precast reinforced concrete box carrying a pedestrian footpath under the Coggeshall Bypass. The structure is likely to require either extending or strengthening as part of Option 3, pending the outcome of an assessment. Information on the Millennium Way Overbridge and the Branch Line Railway Bridge crossing the existing A120 is currently awaited from SMIS and will be reviewed during later project stages.
5.12.6 Proposed Structures
The proposed structures required for all options can be cross-referenced with the Plan and Profile drawings found in Appendix B. Further tabulated structure details can also be found in Appendices D & E.
All options are required to cross the Great Eastern Main Line railway in order to tie into the A12. This will require early liaison with Network Rail to agree track possessions as well as technical approval of the structure. Additionally, Options 1 and 8 also have a rail crossing which is required to pass under the Braintree Branch line. This is likely to be a technically complex structure such as a jacked box which will require substantial liaison and planning with Network Rail.
Options 3, 4B and 1B all cross the River Blackwater, although Option 3 crosses in a difference location to Options 1B and 4B. These crossings require a large viaduct (approximately 200 m long) structure over the river in order to keep any embankments out of the flood zone and minimise the need for any flood compensation. Options 1B and 8 also cross the River Brain requiring a viaduct approximately 100 m long. All river crossings will incorporate environmental constraints as required.
All the options require a large number of NMU and accommodation bridges, the need for which will be refined as further consultation takes place. It is proposed that during later design stages these structures are standardised, requiring less design work and creating more possibilities for pre-fabricated construction and cost savings through economies of scale. At this stage of design, accommodation bridges have been designed to serve the dual purpose of carrying NMU’s.
Integral bridges will be proposed where possible to provide low maintenance and sustainable assets at reduced whole life costs.
All options also cross a number of side roads which will require structures over the proposed A120, again it is proposed that in the later scheme stages, design of these structures can be standardised. Structures have been designed to accommodate NMU’s where required, see section 5.12.7.
All the Options have a number of culverts greater than 0.9 m in diameter, which are therefore classified as structures.
In total Options 1, 3, 4b , 8 and 9 have 26, 32, 25, 23 and 23 structures respectfully.
5.12.7 Non-Motorised Users
Options Impact - NMU
Options have been assessed to identify whether they create severance for NMUs, and whether the severance is mitigatable. The table below shows the number of NMU facilities, by option which are affected. They are categorised into public rights of way (footpaths, bridleways and byways), and other footways and cycle paths.
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The table shows that option 3 intersects significantly more NMU facilities than other options. The remainder have a broadly equal impact.
Option Option Option Option Option 1b 3 4b 8 9a
PROW Footpaths 17 18 13 16 12 affected
PROW Bridleways 1 8 0 1 1 affected
PROW Byways 0 1 1 0 1 affected
Footway/ cycle routes 1 3 3 1 3 affected
TOTAL 19 30 17 18 17
Table 37: Crossings of NMU Facilities by Option Options Assessment – NMU Severance and Public Transport Accessibility
Each option has been assessed against the scheme objectives which are pertinent to NMUs. These are:-
6. Improve connectivity within communities and integration with the wider transport network by reducing severance and increasing accessibility for local residents.
7. Improve the quality and connectivity of transport provision within the A120 corridor for people using non-motorised forms of transport, such as pedestrians, cyclists and equestrians.
Elements considered include potential severance and level of mitigation possible, opportunities to deal with historic severance, opportunities to link communities, and opportunities to facilitate access to public transport. The table below shows the overall assessment by option for both non-motorised users and public transport users based on these objectives.
The assessment presumes that for all options, crossings of new dual carriageway routes would be grade separated with minimal diversion of NMU facility, and that severance created by enlarged grade separated junction improvements would be mitigated to provide improvements, by provision of local facilities to enable users to access facilities on the correct side of the alignment. Side road bridges would be future proofed for NMU use. It is also presumed that NMUs would be prohibited from the new route (Expressway standards), and that suitable alternative facilities would be provided where desire lines would require this. This would include provision of a facility on the proposed local Access road between Bradwell junction and Coggeshall.
Consideration of opportunities to reduce severance on the existing bypassed route would need detailed consideration as part of de-trunking proposals.
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Initial consideration has been given to proposed development adjoining the route, and initial workshops with road user groups and NMU groups, and discussions with the Local Highway Authorities have been initiated to inform the development of the options. At PCF Stage 2, an NMU Context Report would be developed, based on the preferred option.
Opportunities to Reduce Severance
The following opportunities have been identified at stage 1 to improve existing severance, some of which are option specific. Further opportunities may be identified at stage 2 of the project, and particularly as adjoining development proposals, requirements and opportunities become clearer:-
1. Reinstatement of severed links across A120 in the vicinity of the River Brain bridge between south Braintree and the countryside to the south of A120 (all options indirectly affected – options 1b and 8 directly affected) 2. Provision of a west/east link on the north side of the proposed A120 alignment between the east side of the River Brain and the west side of Braintree Road (B1018), avoiding the at-grade crossing of the Braintree to Witham railway line (Options 1b, 4a). 3. Provision of a link across the proposed alignment alongside the railway line (Options 1b, 4a) 4. Improvement of links between Cressing Road, Braintree and Cressing (All options) 5. Provision of link between Bradwell and west Coggeshall along the local access road (Option 3) 6. Improvements of links for NMUs across Coggeshall bypass (Ambridge Road; Colne Road; Tilkey Road subway; Tey Road/Essex Way). 7. Provision of link between Sniveller’s Lane and existing A12 NMU facility using new A120 bridge across the Great Eastern Main Line. (Options 8 and 9a). 8. Provision of link between Lanham Green Road and existing public rights of way to the east. (Options 1b and 8). 9. Improved operability and crossing safety for NMUs at bus stops on existing A120, Marks Farm to Bradwell; Coggeshall to Marks Tey (Option 3). 10. Improved operability and crossing safety for NMUs at bus stops on existing A120, Marks Farm to Marks Tey (Options 1b, 4a, 8 and 9a).
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Core Overall Scheme Option Option Option Option Option Programme Objective 1b 3 4a 8 9a Objective
6) Improve connectivity within communities and integration with the wider transport 1 1 1 1 1 network by reducing severance and increasing accessibility for A More local residents. Accessible and Integrated 7) Improve the Network quality and connectivity of transport provision within the A120 corridor for people 1 1 1 1 1 using non- motorised forms of transport, such as pedestrians, cyclists and equestrians.
Table 38: Options Assessment – NMU Severance / Safety and Public Transport Accessibility Category Description
-3 Significant Impact - Will have likely significant Adverse impact – not possible to Mitigate. -2 Major Impact - Potential Major Adverse Impact – mitigation maybe possible
-1 Minor Impact - Possible Minor Adverse Impact, not significant with mitigation.
0 Neutral - No Impact
1 Minor - Minor Beneficial Impact
2 Major - Major Beneficial Impact
3 Significant - Significant Beneficial Impact
Table 39: Options Assessment Categories
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5.12.8 Construction assessment
Background construction approach
The construction methodology is founded around enabling key construction targets to be met. These are as follows:
• To open the upgraded sections of the A120 to traffic in 2026.
• Minimising disruption to the local and wider community where possible.
• Ensuring safe working throughout the process.
• Limiting import material required by means of onsite material excavation.
The scheme is heavily earthworks driven therefore ensuring an earthworks balance is a key driver in determining the construction methodology. The methodology would look to minimise earthworks movements by establishing clear routes early on and limiting required haulage distance by utilisation of soil storage areas, compounds and borrow pits located across the scheme.
Later development stages will establish whether early construction works are required and where possible when concurrent works (e.g. utilities) can be conducted. Major utility diversions will have to be taken into account and the methodology built around these constraints.
Environmental mitigation requirements will be identified for each section during later project stages and fed into the methodology, although for the purposes of this report it is assumed all environmental mitigation works will be conducted prior to construction.
It is assumed that pavement, drainage, technology, landscaping and other works will run concurrently or sequentially in some instances.
The five options and major construction quantities and activities are listed below.
Option 1b
Option 1b is described in section 5.8. The majority of the route is offline, however the junction tie ins will require some online working.
Key Quantities • Cut ~1,700,000 m3 (not inc. Quarry crossing) • Fill ~2,000,000 m3 (not inc. Quarry crossing) • Disposal of Contaminated material ~40,000 m3 • Import material to make up balance and ~700,000 m3 • Major Structures 5 no major junctions and railway crossings • Minor Structures 16 no single track road/foot bridges
Works specific – Major Activities • Approx. 1.70m cbm of cuttings. Estimated 25% of material is unusable. Requiring import of approx. 0.70m cbm to create earthworks. • A new proposed Galley’s corner bypass will be constructed which will have a dumb-bell junction with overbridge to allow moving online and offline traffic onto A120. • Precast and sliding of new mainline underpass structure of the Network Rail Braintree Branch line. Carried out during possession, potentially at Christmas requiring 2 years advance booking. • Crossing the Bradwell Quarry, the remediation methodology for Bradwell currently proposed is to dig out the materials and replace as detailed in section 5.12.2. The volumes for the quarry excavation for
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option 1B are 4.0m cbm. A Dynamic compaction option for quarry remediation will also be investigated at later project stages. • Bridge over the Great Eastern Railway Line on earth embankments with precast/steel spanning members. Possibly Christmas possession as above. • River Blackwater viaduct structure approx. 200m long. • It is assumed that the A12 J24A fill will be imported from the A12. The fill volume will be approximately 0.3m cbm. Potentially more economical to upgrade the permanent structure to work as haul road during construction phase, rather than build a dedicated temporary crossing. This will need to be carried out early in the project to facilitate earthworks movements east-west for the rest of the scheme. • Bridge over existing A12 alignment and associated slips on raised earth embankments. Depending on bridge design could be carried out under TTM without full closure. Would require a two-span bridge with support in the central reservation of existing A12. • The construction of 16 minor structures consists of various side access roads such as Ashes Rd, Links Rd, Non-motorised users bridges such as Pantling’s Lane, Bradwell Quarry access etc. • Significant TTM phasing required to tie-in western end of route to existing A120.
The route produces a shortfall in the balance of earthworks cut and fill volumes, the expected percentage of unusable material will require an extra 700,000m3 of material to be imported to complete the works. The unusable material will either have to be taken to landfill or remediated for use in other works. Another potential use is for backfill and remediation of the quarry at Bradwell.
It is estimated that this route will take approx. 2.5 – 3 years to construct not including preliminary service / utility diversions and any environmental mitigation which will be defined by the upcoming environmental site surveys. There are various HV cables and LHP mains around the proposed Braintree junction and will require diversion.
Option 3
Option 3 is described in section 5.6. Of the total 14km length, only approx 2km of the route, around the Coggeshall Bypass, is directly constructed online, another 3km is adjacent or close to the existing route.
Key Quantities • Cut ~900,000 m3 • Fill ~1,900,000 m3 • Disposal of Contaminated material ~22,000 m3 • Import material to make up balance and ~1,200,000 m3 • Major Structures 8 no major junctions and/or railway crossings • Minor Structures 12 no single track road/foot bridges
Works Specific – Major Activities • Approx. 0.90m cbm of cuttings. Estimated 25% of material is unusable. Requiring import of approx. 1.20m cbm to create earthworks. • There are several junctions to be constructed in this option such as Galley’s Corner, Doghouse Road, Colne Road, Colchester Road and the proposed A12 junction 24A. • Detailed sequencing of activities and TTM will be required to minimise disruption to motorists and residents alike. The proposed New Galley’s corner junction is grade separated with diversion of adjoining arms. • River Blackwater viaduct structure approx. 200m long. Approx. 1m cbm of fill material needs to be transported over the river at this location. It is assumed to that the A12 J24A fill is imported from the A12. • Online widening of A120 around Coggeshall Bypass will require significant TTM and/or diversion to cope with necessary speed restrictions during construction of this phase. • Large grade separated junction and slips/approaches at Colchester Road as online widened section departs the existing road and continues southwards. • Bridge over the Great Eastern Railway Line on earth embankments with precast/steel spanning members. Possibly Christmas possession as above.
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• Bridge over existing A12 alignment and associated slips on raised earth embankments. Depending on bridge design could be carried out under TTM without full closure. Would require a two-span bridge with support in the central reservation of existing A12. • Construct 12no other dual-single track bridges, Non-Motorised bridges for small local roads crossing the new mainline.
The route produces a shortfall in the balance in terms of earthworks cut and fill volumes, the anticipated volume of unusable material will necessitate the import of approx. 1.20m cbm of fill. The unusable material will either have to be taken to landfill or remediated for use in other works. Another potential use is for backfill and remediation of the quarry at Bradwell.
It is estimated that this route will take approx. 2.5 - 3years to construct not including preliminary service / utility diversions and any environmental mitigation to be developed at later project stages. The Galley’s corner junction is congested with a high density of utilities such as Electricity cables, LHP mains, BT underground and overhead cables and Anglian water are all located in the surrounding area of Galley’s corner junction which will need diversion.
Option 4b
Option 4b is described in section 5.7. The entire route is offline construction, except for the junction tie ins at either end.
Key Quantities • Cut ~900,000 m3 (not inc. Quarry crossing) • Fill ~1,850,000 m3 (not inc. Quarry crossing) • Disposal of Contaminated material ~20,000 m3 • Import material to make up balance and ~1,150,000 m3 • Major Structures 5 no major junctions and railway crossings • Minor Structures 14 no single track road/foot bridges
Works Specific – Major Activities • Approx 0.90m cbm of cuttings. Estimated 25% of material is unusable. Requiring import of approx. 1.150m cbm to create earthworks. • Detailed sequencing of activities and TTM will be required to minimise disruption to motorists and residents alike. • Crossing the Bradwell Quarry, the remediation methodology for Bradwell currently proposed is to dig out the materials and replace as detailed in section 5.12.2. The volumes for the quarry excavation for option 4B are 4.0m cbm. A Dynamic compaction option for quarry remediation will also be investigated at later project stages. • River Blackwater viaduct structure approx. 200m long. Approx. 0.5m cbm of fill material needs to be transported over the river at this location. It is assumed that the A12 J24A fill is imported from the A12. • Bridge over the Great Eastern Railway Line on earth embankments with precast/steel spanning members. Possibly Christmas possession as above. • Bridge over existing A12 alignment and associated slips on raised earth embankments. Depending on bridge design could be carried out under TTM without full closure. Would require a two-span bridge with support in the central reservation of existing A12. • Construct 14no other dual-single track bridges for small local roads crossing the new mainline.
The route produces a shortfall in the balance of cuttings to fill. This is exacerbated by the nominal loss of 25% of the material as unusable for fill. This necessitates the import of approx. 1.15m cbm of fill. The unusable material will either have to be taken to landfill or remediated for use in other works. Another potential use is for backfill and remediation of the quarry at Bradwell.
It is estimated that this route will take approx. 2.5 - 3years to construct not including preliminary service / utility diversions and any environmental mitigation which will be developed at later project stages. This option has significant impact on the statutory undertaker’s plants around the Galley’s Corner junction which has a high
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density of various electricity cables, water and Gas mains. HV cables runs from fowler’s farm to Galley’s corner then along the existing A120 verge.
Option 8
Option 8 is described in section 5.10. The majority of the route is offline, however the junction tie ins will require some online working.
Key Quantities • Cut ~2,200,000 m3 • Fill ~1,950,000 m3 • Disposal of Contaminated material ~40,000m3 • Import material to make up balance and ~175,000 m3 • Major Structures 6 no major junctions and railway crossings • Minor Structures 13 no single track road/foot bridges
Works Specific – Major Activities • Approx. 2.20m cbm of cuttings. Estimated 25% of material is unusable. Requiring import of approx. 0.175m cbm to create earthworks. • Crossing the Bradwell Quarry, the remediation methodology for Bradwell currently proposed is to dig out the materials and replace as detailed in section 5.12.2. The volumes for the quarry excavation for option 8 are 2.5m cbm. A Dynamic compaction option for quarry remediation will also be investigated at later project stages. • Precast and sliding of new mainline underpass structure of the Network Rail Braintree Branch line. Carried out during possession, potentially at Christmas requiring 2 years advance booking. • Bridge over the Great Eastern Railway Line on earth embankments with precast/steel spanning members. Possibly Christmas possession as above. • Bridge over existing A12 alignment and associated slips on raised earth embankments. Depending on bridge design could be carried out under TTM without full closure. Would require a two-span bridge with support in the central reservation of existing A12. • Construct ~13no other dual-single track bridges for small local roads crossing the new mainline. • Significant TTM phasing required to tie-in western end of route to existing A120.
The route produces a small shortfall in term of balance in cut and fill volumes, this coupled with the anticipated volume of unusable materials results in a small volume of approx. 175,000 cbm of import fill required.
There are various HV cables and LHP mains around the proposed Braintree junction and will require diversion. It is estimated that this route will take approx. 2-2.5 years to construct not including preliminary service / utility diversions and any environmental mitigation which will be defined during later project stages. The reduction in time is associated with the shortened overall length of the route as well as not requiring a viaduct across the R. Blackwater.
Option 9a
Option 9a is described in section 5.9. The entire route is offline construction except for the junction tie ins at either end. Key Quantities
• Cut ~1,300,000 m3 • Fill ~1,900,000 m3 • Disposal of Contaminated material ~20,000 m3 • Import material to make up balance and ~800,000 m3 • Major Structures 5no major junctions and railway crossings • Minor Structures 11no single track road/foot bridges
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Works Specific – Major Activities
• Approx. 1.30m cbm of cuttings. Estimated 25% of material is unusable. Requiring import of approx. 0.8m cbm to create earthworks. • Crossing the Bradwell Quarry, the remediation methodology for Bradwell currently proposed is to dig out the materials and replace as detailed in section 5.12.2. The volumes for the quarry excavation for option 9 are 2.5m cbm. A Dynamic compaction option for quarry remediation will also be investigated at later project stages. • Detailed sequencing of activities and TTM will be required to minimise disruption to motorists and residents alike. • Bridge over the Great Eastern Railway Line on earth embankments with precast/steel spanning members. Possibly Christmas possession as above. • Bridge over existing A12 alignment and associated slips on raised earth embankments. Depending on bridge design could be carried out under TTM without full closure. Would require a two-span bridge with support in the central reservation of existing A12. • Construct ~11no other dual-single track bridges for small local roads crossing the new mainline.
The route produces significantly less cuttings than are required; this coupled with the anticipated volume of unusable materials results in a large volume of approx. 0.8m cbm of import fill required.
It is estimated that this route will take approx. 2years to construct not including preliminary service / utility diversions and any environmental mitigation which will be defined during later project stages.
Due to this being the shortest route with the minimum of structures, this should prove to be the cheapest route option currently under consideration.
Route Ranking
The above brief assessments of bulk quantities and structures for the five route options has led to the following ranking of the routes with 9a being most preferred down to 1b being least preferred. All of the routes are considered practicable to build and whilst some routes are more challenging, there are no especially unusual issues. It should be noted that this ranking is based purely on the ease of construction.
Route In order of Primary Reasons preference
9a 1 Shortest Route, minimum of structures, entirely offline. But larges volume of import material.
8 2 Slightly longer than 9b, although requires significantly less import it crosses the railway twice and affects 132kV pylons
3 3 Only option with any online element and large number of junctions
4b 4 Crosses Bradwell Quarry which is a large unknown factor.
1b 5 Crosses Bradwell Quarry and beneath live BBL.
Table 40: Constructability Assessment Option Preference
5.12.9 Other Engineering Considerations
None have been identified.
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6. TRAFFIC ANALYSIS
Full details of the traffic analysis are contained in the Stage 1 Traffic Forecasting Report (Doc Ref: B3553T41- JAC-HGN-00-REP-TR-000), with the underlying data collection described in the Traffic Data Collection Report (Doc Ref: B3553T41-JAC-HGN-00-RP-TR-0001).
6.1 Traffic Data and Model
6.1.1 Background to modelling
ECC commissioned Jacobs to develop a local traffic model to assess the different proposed scheme options to provide inputs for the public consultation on the options and further appraisal and design. The key purpose of the local model is to assist in the appraisal and understanding of the impacts of the proposed A120 Braintree to A12 scheme options for PCF Stage 1 with respect to meeting the objectives outlined in the previous section. The Forecast Model has been prepared for two future year scenarios, the 2026 (opening year) and the 2041 (design year).
6.1.2 Development of the Traffic Model: The development, calibration and validation of the local traffic model is fully described in the A120 Braintree to A12 Stage 1 Local Model Validation Report (Doc Ref: B3553T41-JAC-GEN-00-RP-C-006).
The methodology used to estimate future year traffic flows is described in the A120 Braintree to A12 Stage 1 Traffic Forecasting Report (Doc Ref: B3553T41-JAC-HGN-00-REP-TR-0001).
6.1.3 Traffic Flows
The changes in traffic flows have been assessed to ensure that the changes make sense and are in the expected order of magnitude. The model considers actual traffic flows (AM period, Inter peak period and PM period) for core growth scenario on the strategic road network for all options in the opening year 2026 and design year 2041 respectively.
The comparison shows that the proposed new alignments for the A120 have a significant impact on the existing A120, where traffic flows decrease substantially as one would expect.
The main changes in traffic flow identified for the AM, Inter Peak and PM periods in the opening and design years are as follows:
• Traffic flows decrease significantly along the existing A120 including through the towns of Bradwell and Marks Tey. • Traffic flows decrease on a number of local roads used as rat-runs in the Reference Case due to the lack of capacity on the existing A120. This includes a reduction in traffic through local towns such as Coggeshall, Silver End, Kelvedon and Witham. • Traffic flows increase along the A120 Braintree bypass to the west of the scheme given that this is the access point to the new A120. • Traffic flows increase along the A12 from J22 to J25 in Option 8 and 9b as the new A120 ties in at J22 with the A12. • Traffic flows increase along the A12 from the new interchange proposed between J24 and J25 in Options 1b, 3 and 4b and Marks Tey (J25).
These changes in traffic flows make sense in terms of the sign and the magnitude within the context of the location and operation of the scheme and the capacity of available local rat-runs on the road network.
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There are significant flow reductions on the local roads. In effect, the growth in traffic in the A120 corridor after 2016 is largely being accommodated on local road rat-runs as opposed to the existing A120 due to the high levels of existing delay.
More specifically, there are reductions in traffic flows on the secondary roads connecting the existing A120 and the A12, such as the B1024 Coggeshall Road, B1018 Cressing Road, Church Road, Parkgate Road and Witham Road as vehicles transfer to the new proposed A120 schemes from these local roads.
There are also changes in the traffic flow along the A12. In Option 1b, 3 and 4b, traffic flows along the A12 decrease south of the new interchange between the proposed A120 bypass and the A12 and increase to the north up to Junction 25 with the existing A120. However, in Option 8 and 9b where the proposed A120 bypass joins the A120 further south at Junction 23 (South Kelvedon), traffic flows increase along the whole section of the A12, with a marginally smaller increase south of Junction 23.
6.1.4 Journey times
There are a highly significant time saving for trips on the A120 corridor via the proposed scheme options in the order of 7.3 to 13.7 minutes depending on the time period and direction in 2026. There are also significant time savings for trips on the existing A120 compared to the reference case, albeit lower than via the proposed schemes, in the order of 3.5 to 8.3 minutes depending on the time period and direction in 2026.
There are also reductions in travel time on local roads being used as rat-runs to avoid the existing A120, in particular on routes 1 (Ashes Road/Boars Tye Road/Western Road/Park Road/Church Road) between Braintree town and Rivenhall End, route 2 (B1018) between Braintree town and Witham and the A131 from the north and south into Braintree town.
For option 8 and 9b in particular, there are journey time increases on the A12 in the order of 20 to 40 seconds due to increased traffic between Junction 23 Kelvedon south and Junction 25 at Marks Tey.
Similarly, for options 3, 8 and 9b there are increases in the journey times on Coggeshall Road between Coggeshall and Kelvedon in the order of 10 to 50 seconds depending on the time period and direction of travel. However, for options 8 and 9b two-way traffic is forecast to fall overall along the full length of this route. The reason for increases in journey times appears to be related to changes in the direction split of traffic, for example, there is an increase in traffic entering Kelvedon from the new all movements junction from the south via options 8 and 9b even though there is a reduction in the opposite direction. This appears to be resulting in isolated junction delays due to the changed traffic patterns. This will be addressed in Stage 2 modelling, which will consider some of the more detailed local operational impacts of the proposed schemes.
6.1.5 Conclusion
The robust estimate of the traffic flows likely to occur along the new alignment of the A120 and on the surrounding network are considered sufficiently robust to inform the Stage 1 economic appraisal of the scheme value for money and to inform public consultation.
The Stage 1 traffic model is capable of producing sufficiently accurate estimates of existing traffic conditions within the study area, and in particular around the A120 Braintree to Marks Tey corridor, such that the final validation results meet the criteria outlined by DfT guidance in TAG Unit M3. It is considered that the model can be used with confidence to estimate a robust set of future traffic flows for proposed schemes to upgrade the A120 for Stage 1 appraisal.
The Local Model Validation Report demonstrated that the base year traffic model complied with DfT guidance in TAG Unit M3.1 with respect to model validation and provides of robust basis for developing the Forecast Model. Confidence in these future traffic flows is sufficient to provide input into Stage 1 economic appraisal to inform the public consultation process.
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7. ECONOMIC ASSESSMENT
An economic assessment has been undertaken to understand the costs and benefits of the options. Full details of the methodology and results of this assessment are provided in the A120 Braintree to A12 Stage 1 Economic Assessment Report (Doc Ref: B3553T41-JAC-HGN-00-REP-TR-0002)
7.1 Economic Assessment Methodology
For the methodology employed for economic modelling refer to the Stage 1 Economic Assessment Report .
7.2 Results
7.2.1 Headline results – initial BCR
The headline results from the economic assessment relate to those impacts that can be monetised and aggregated together as per DfT guidance. For this Stage 1 economic assessment, this includes transport user benefits in terms of travel time savings and changes in vehicle operating costs as well as changes in indirect tax revenues, greenhouse gases and accident costs.
The standard measures for economic assessment are the present value of benefits (PVB), present value of costs (PVC), the difference between them in the form of a net present value (NPV) and the ratio of benefits to costs (BCR). These values are reported in 2010 market prices discounted to a 2010 base year as per DfT guidance.
The calculated BCRs are shown in the table below:
Item Option 1b Option 3 Option 4b Option 8 Option 9b
Present Value of Benefits (PVB) 933.6 841.7 856.2 721.4 678.3
Present Value of Costs (PVC) 651.7 478.9 571.9 451.2 373.5
Net Present Value (NPV) 281.9 362.8 284.3 270.2 304.8
Benefit Cost Ratio (BCR) 1.43 1.76 1.50 1.60 1.82
Table 41: Headline Economic Results (£ millions, 2010 market prices discounted to 2010 base year)
The results in the above table highlight that the higher the scheme benefits the higher the scheme costs. The BCR that distinguishes between the relative costs and benefits of a scheme ranges from 1.43 to 1.82 for option 1b and option 9b respectively, which also coincide with the highest and lowest costs respectively.
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7.2.2 Adjusted BCR calculation
The adjusted BCR taking into account the wider impacts of the scheme are shown in the table below:
Item Option 1b Option 3 Option 4b Option 8 Option 9b
Present Value of Benefits (PVB) from AMCB table 933.6 841.7 856.2 721.4 678.3
Wider impacts (WI2) 41.4 36.4 38.2 29.2 27.5
Adjusted PVB 975.0 878.1 894.4 750.6 705.8
Present Value of Costs (PVC) 651.7 478.9 571.9 451.2 373.5
Net Present Value (NPV) 323.3 399.2 322.5 299.4 332.3
Adjusted Benefit Cost Ratio (BCR) 1.50 1.83 1.56 1.66 1.89
Table 42: Adjusted BCR Calculation (all monetary values in £ million, 2010 prices discounted to 2010)
It should be noted that as the scheme, modelling and assessment develops in PCF Stage 2 the adjusted BCR calculation will include monetised assessments for journey time reliability, the wider impacts of agglomeration and tax revenues arising from labour supply market impacts and the impacts of dependent housing. It is anticipated that these are all expected to provide significant positive benefits and increase the BCRs from those shown above
7.3 Comparison of options It can be concluded that the higher the cost of the scheme the higher the overall level of benefits. There is a wide range in the cost of the options, by nearly a factor or two. The central options, 1b and 4b, whilst the most expensive, also provide the most direct route for the principal A120 west to A12 north movement; the southern options, whilst considerably cheaper to construct, rely on a greater length of the A12 and have a longer total journey length.
Option 1b is the highest cost option but also has the highest overall benefits. Accident benefits are similar to the other options and it has the lowest impact on greenhouse gas emissions. Option 4b has a lower cost and overall benefits than option 1b but higher than all other options. It has the lowest accident benefits.
Option 9b is the lowest cost option and has the lowest overall benefits. While having the lowest overall benefits it has very similar accident benefits to option 8, which has the highest accident benefits. This option has the highest negative impact on greenhouse gas emissions. Option 8 is more expensive than option 9b but again accrues higher overall benefits and has the highest accident benefits. Option 3 is a distinct partially online option with an estimated cost between those of options 1b/4b and options 8/9b. Overall benefits, accident benefits and greenhouse gas emissions all also lie between the range of these options. The BCR, which distinguishes between the relative differences between the costs and benefits, indicates that option 9b represents higher value for money than the other options with an initial BCR of 1.82. Option 3 is next with a BCR of 1.76, followed by option 8 with 1.60, option 4b with 1.50 and option 1b with 1.43.
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7.4 Conclusions on BCR
The key conclusions from the economic assessment are as follows: • Based on the initial BCR, all options except option 1b fall into the medium value for money category defined by DfT guidance 6. • The initial BCR calculation however, currently excludes noise benefits, which are expected to be beneficial, and local air quality impacts, which are expected to be slightly negative 7. The cost of delay during construction and maintenance is also not included. Neither are expected to be highly significant in magnitude in terms of the overall scheme benefits but will be monetised as part of Stage 2. • Key benefits that are not to be included in the initial BCR based on DfT guidance include wider economic impacts, journey time reliability benefits and the impact of dependent housing. Some of the wider economic impacts – output change in imperfectly competitive markets (WI2) - have been monetised in this economic assessment resulting in an adjusted BCR of 1.50 for option 1b and 1.89 for option 9b. Option 1b is therefore considered to fall into the medium value for money category when considering all the available evidence on monetised benefits. • It should be noted that about an additional PVB of £40 million would result in option 9b having an adjusted BCR of 2.0. Given the positive qualitative assessment of the remaining wider economic impacts, journey time reliability benefits and dependent housing impacts and the context of highly significant journey time savings, which drive those benefits, it is considered that option 9b provides high value for money. This will be verified in Stage 2 along with the value for money of the other options when these benefits will be monetised. This is outlined in more detail in the A120 Braintree to A12 Stage 1 Business Case . • It should further be borne in mind that the cost of traversing Bradwell Quarry is a large component of the central (1b and 4b) and to a lesser degree the southern (8 and 9a) options. As explained in this report, a conservative approach has been taken with regard to its treatment at this early stage due to lack of information and it is anticipated that further design, testing and discussions with the quarry operator should allow a less expensive solution to be developed. This, thus, further points to retention of all options at this stage.
Considering the above, whilst there are differences in BCR between the options they are not significant enough as to warrant rejection of any options on this basis.
7.5 Business case
The Stage 1 Outline Business Case (Doc Ref: B3553T41-JAC-HGN-00-REP-C-0002) draws together the economic and other analyses.
The overall conclusions of this stage of the appraisal are as follows: • There is a clearly established need for intervention on the A120 corridor. A lack of capacity relative to demand on the corridor results in significant levels of congestion related delay and poor journey time reliability and contributes to a lack of resilience and a poor safety record. This strategic trunk route also passes through a number of local villages causing severance, noise and local air quality issues. • A comprehensive appraisal process following WebTAG guidelines has been undertaken, identifying nine potential options to take forward into Stage 1. Additional work has been undertaken during Stage 1, to further reduce the number of options prior to public consultation to five. • Based on the Stage 1 economic assessment, all five options have been shown to provide medium value for money. There is potential for a higher value for money ratings when further benefits are monetised in Stage 2.
6 DfT December 2013: Value for Money Assessment: Advice Note for Local Transport Decision Makers 7 Jacobs, December 2016: A120 Braintree to A12 Stage 1 Environmental Assessment Report
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• There is broad stakeholder support for a significant intervention on the A120 corridor. • Formalised governance and engagement processes are already in place. • Key risks and dependencies have been identified with mitigation measures being implemented.
Given the above, it is proposed that all five options be taken forward to the next stage of the appraisal process
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8. SAFETY ASSESSMENT
8.1 Impact on Road User - Strategic Safety Action Plan The scheme option proposals have been considered and reviewed in the context of the overall scheme objectives, including safety.
This overall scheme objective is based on the existing Highways England’s Key Performance Indicator, that the level of killed and serious (KSI) injured casualties be decreased by at least 40% by the end of the year 2020, based on the 2005 – 2009 baseline. Additionally, Highways England’s aspiration is for no-one to be hurt whilst using or working on the strategic road network. The Roads Investment Strategy contains an aspiration for zero KSIs by the year 2040. It should be noted that detailed safety objectives would be developed at PCF stage 2, as part of the PCF Safety Plan.
Highways England’s Expressway Technical Note (2016) describes a safety objective for Expressway routes as providing a similar safety performance as a dual 3 lane motorway (D3M) (without MIDAS). Additionally it is expected that no road user group would be adversely disproportionately affected. In order to meet these objectives, a suite of 15 characteristics are required to be adopted. It is accepted that MIDAS contributes a 13% reduction in collisions, so the measure of new route performance for an Expressway standard route has been taken as D3M plus 13%.
A COBA LT assessment will be carried out based on traffic modelling for use in the Business Case. The road user safety assessment of each option for this Technical Appraisal Report has been undertaken based on the following parameters:-
• Likely impact on KSI performance of the route (based on fatal weighted index (FWI). FWI considers collisions in the rough proportions which they occur in national statistics. (1 fatal = 1; 1 serious = 0.1; 1 slight = 0.01). • Compliance with Expressway characteristics, and achievement of Expressway safety objectives. • Initial consideration of potential impact on existing routes in the study area. • Initial assessment of departures from standards • Potential effect on individual road users groups, including non-motorised users (NMU).
The existing safety performance of A120 between south-west of Galleys Corner (A120/B1018/Cressing Road/Long Green) and Marks Tey junction (A120/A12 J25), based on the period 2011 to 2015 (selected elements are based on the 2010 – 2014 baseline) are identified in the ‘Existing Safety Conditions’ section of this Technical Appraisal Report, and locations of collisions involving personal injury are shown on plans in Appendix C. Highlights of the existing safety performance are summarised as follows:-
• The level of both casualties and collisions on A120 in the study area was above the five year average (based on 2011-2015), during 2014 and 2015. • The level of KSI collisions was lower than the five year average (based on 2011-2015) during 2015, but higher in 2011 and 2014. • The level of slight injury collisions was higher than the five year average (based on 2011 – 2015) during 2014 and 2015. • Collision clusters (more than 4 collisions per annum) were identified at A120/B1018 Galley’s Corner and A120/A12 J25, Marks Tey (NB some collisions are on A12 at this location); additional collision clusters were identified at five other locations on A120, and at two locations on A12 in the study area. • A group of non-motorised user collisions was identified on A120 between the village of Little Tey and Marks Tey. • Overall, no road users are disproportionately adversely represented in the statistics. • Some sections of A120 do not provide a safe environment for NMUs – in some lengths, NMU facilities are discontinuous, change from one side of the road to the other and are of varying widths. There are no cycle facilities at Marks Tey junction although there is a footbridge over the A12. There is a shared cycleway/footway underpass at A120/B1018 Galleys Corner junction, and there are pelican crossings in the village of Bradwell and at Marks Tey.
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Impact on Road Workers – Strategic Safety Action Plan
This assessment will cover impact on road workers during the operation and maintenance of the route after its commissioning. Highways England has an overall objective that no-one should be harmed whilst using or working on the strategic road network. This builds on Highways Agency’s Policy of Aiming for Zero for road workers, which has resulted in a number of initiatives such as eliminating crossing of live carriageways by the end of 2016.
There will be no specific numerical safety objective set for road workers. This risk will be managed in accordance with the requirements of the Health and Safety at Work Act to be reduced So Far As Is Reasonably Practicable (SFARP). This is a legal requirement.
The introduction of Expressway roads would reduce risk for road workers in a number of ways. These include the use of concrete barriers, which reduce the level of maintenance and replacement works required, thus reducing exposure to risk, introducing combined emergency and maintenance bays and technology, all of which can improve protection of road workers and facilitate safer maintenance of additional technology assets, and introduction of a five year non-maintenance period after handover of a scheme for operation. Each option has been assessed to consider the impact on road worker safety. Road workers include Highways England employees including traffic officers and supply chain workers working on contracts on behalf of Highways England.
Option Assessment Summary (Road User and Road Worker Safety)
Each of the options is assessed below and a summary of the safety performance of the options is provided in a table at the end of the section.
Option 1b
This option would provide a D2AP Expressway which would commence just west of the existing River Brain bridge and continue to the south of the existing A120 alignment, joining the A12 south-west of the existing junction at Marks Tey on A12. A new junction would be provided to the south-east of the existing Galleys Corner junction, with local road links on the south side of the existing A120 to Long Green and Fowlers Farm roundabout, and across the proposed A120 to a new roundabout on the existing A120 north of Cressing Road. A local link road would be provided from the existing A120 south of Marks Farm to provide a link for A131 traffic to the new grade separated junction. A further grade separated junction would be provided linking the existing A120 with the new route just west of the River Brain.
The route is likely to perform in accordance with Expressway safety objectives (provided all elements are provided), which could result in substantial reductions in SRN KSI and casualty rates compared with the existing single carriageway route. There are no significant departures from standards which would require mitigation to operate safely.
Initial assessment of the residual existing route and other local roads suggests traffic flows would be reduced significantly by this option (informed by traffic modelling). This would also reduce the casualty rates but mitigation may be required to avoid increased traffic speeds through reduced congestion, resulting potentially in affecting the level of KSIs. This option may provide ability to introduce enhanced NMU facilities and deal with severance issues. The section of A12 between the existing A120 junction (J25) and the proposed junction would be subject to an increased traffic flow, with corresponding effect on collisions.
The option is assessed as providing significant safety benefits.
Road worker safety on the proposed route would be improved significantly over the existing route by the provision of a range of measures, including concrete barrier, fixed taper points and combined emergency/maintenance bays, which would reduce maintenance interventions and exposure to risk, or ensure they are designed to maximise safety of road workers and road users. Road worker safety on the existing route would not be improved but reduction in traffic flows (levels informed by traffic modelling) might facilitate greater time periods when works could be carried out. Incidents may also be reduced.
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Option 3
This option would provide a D2AP Expressway off-line improvement starting from Galleys Corner and following an alignment crossing the existing A120 route to the west of Bradwell. It would continue on-line to the east of Coggeshall, and then off-line to a new junction with the A12, south-west of the existing junction on A12 at Marks Tey. The option would include a grade separated junction east of the existing junction at Galleys Corner, with a D2AP link back to A131 to the north of the location and single carriageway local road links to B1018, Fowlers Farm and Galley’s Corner junctions. Grade separated junctions are provided at the intersection with the A12, and additionally at Bradwell (east) and Coggeshall (east). A compact grade separated junction is provided at Colne Road, north of Coggeshall, with left in/left out manoeuvres permitted from each main carriageway of A120. Between Bradwell junction and West Street, Coggeshall, a single carriageway local access road is provided adjacent to the main alignment.
The route is likely to perform generally in accordance with Expressway safety objectives (provided all elements are provided), resulting in substantial reductions in SRN KSI and casualty rates compared with the existing single carriageway route. However the volume of additional junctions compared with other options (two grade separated and one compact grade separated junctions are additional), the additional section of single carriageway local access road, and the presence of significant departures from standards, is considered to reduce the potential safety performance of this option compared with other options. Nevertheless this option is assessed as providing major safety benefits (presuming departures can be mitigated appropriately).
Initial assessment of the residual existing route and other local roads suggests traffic flows would be reduced significantly by this option (informed by traffic modelling). This would also reduce the casualty rates but mitigation may be required to avoid increased traffic speeds through reduced congestion, resulting potentially in affecting the level of KSIs. This option may provide ability to introduce enhanced NMU facilities and deal with severance issues. The section of A12 between the existing A120 junction (J25) and the proposed junction would be subject to an increased traffic flow, and thus collisions.
Incidents may also be reduced, and network availability increased.
Road worker safety on the proposed route could be improved significantly over the existing route by the provision of a range of measures, including concrete barrier, fixed taper points and combined emergency/maintenance bays, which would reduce maintenance interventions and exposure to risk, or ensure they are designed to maximise safety of road workers and road users. The presence of additional junctions and departures from standards in this option may increase the complexity of temporary traffic management required for road works, and may have an impact on road worker safety. Road worker safety on the existing route would not be improved but reduction in traffic flows (levels informed by traffic modelling) might facilitate greater time periods when works could be carried out.
Option 4b
This option would provide a D2AP Expressway off-line improvement which starts from Galleys Corner and like option 1b, would continue to the south of the existing A120 alignment, joining the A12 south-west of the existing junction at Marks Tey on A12. The option would include a grade separated junction east of the existing junction at Galleys Corner, with a D2AP link back to A131 to the north of the location and single carriageway local road links to B1018, Fowlers Farm and Galley’s Corner junctions.
The route is likely to perform in accordance with Expressway safety objectives (provided all elements are provided), which could result in substantial reductions in SRN KSI and casualty rates compared with the existing single carriageway route. There are no significant departures from standards which would require mitigation to operate safely.
Initial assessment of the residual existing route and other local roads suggests traffic flows would be reduced significantly by this option (informed by traffic modelling). This would also reduce the casualty rates but mitigation may be required to avoid increased traffic speeds through reduced congestion, resulting potentially in affecting the level of KSIs. This option may provide ability to introduce enhanced NMU facilities and deal with
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severance issues on the existing route. The section of A12 between the existing A120 junction (J25) and the proposed junction would be subject to an increased traffic flow, with corresponding effect on collisions.
The option is assessed as providing significant safety benefits, and slightly more than option 1b owing to the lower number of junctions near Braintree.
Road worker safety on the proposed route would be improved significantly over the existing route by the provision of a range of measures, including concrete barriers, fixed taper points and combined emergency/maintenance bays, which would reduce maintenance interventions and exposure to risk, or ensure they are designed to maximise safety of road workers and road users. Road worker safety on the existing route would not be improved but reduction in traffic flows (levels informed by traffic modelling) might facilitate greater time periods when works could be carried out. Incidents may also be reduced.
Option 8
This option would provide a D2AP Expressway off-line improvement which would commence just west of the existing River Brain bridge, Braintree and travel east and then south to join the A12 at junction 23 (south-west of Kelvedon). A new junction would be provided to the south-east of the existing Galleys Corner junction, with local road links on the south side of the existing A120 to Long Green and Fowlers Farm roundabout, and across the proposed A120 to a new roundabout on the existing A120 north of Cressing Road. A local link road would be provided from the existing A120 south of Marks Farm to provide a link for A131 traffic to the new grade separated junction. A further grade separated junction would be provided linking the existing A120 with the new route just west of the River Brain.
The route is likely to perform in accordance with Expressway safety objectives (provided all elements are provided), which could result in substantial reductions in SRN KSI and casualty rates compared with the existing single carriageway route. There are no significant departures from standards which would require mitigation to operate safely.
Initial assessment of the residual existing route and other local roads suggests traffic flows would be reduced significantly by this option (informed by traffic modelling). This would also reduce the casualty rates but mitigation may be required to avoid increased traffic speeds through reduced congestion, resulting potentially in affecting the level of KSIs. This option may provide ability to introduce enhanced NMU facilities and deal with severance issues on the existing A120.
The section of A12 between the existing A120 junction (J25) and the proposed junction would be subject to an increased traffic flow, with corresponding effect on collisions. In this option, a longer length of A12 is affected, although the length of the proposed A120 route is shorter than all other options except option 9a.
The option is assessed as providing significant safety benefits.
Road worker safety on the proposed route would be improved significantly over the existing route by the provision of a range of measures, including concrete barrier, fixed taper points and combined emergency/maintenance bays, which would reduce maintenance interventions and exposure to risk, or ensure they are designed to maximise safety of road workers and road users. Road worker safety on the existing route would not be improved but reduction in traffic flows (levels informed by traffic modelling) might facilitate greater time periods when works could be carried out. Incidents may also be reduced.
Option 9a
This option would provide a D2AP Expressway off-line improvement which starts from Galleys Corner and like option 8, travel east and then south to join the A12 at junction 23 (south-west of Kelvedon). A new junction would be provided to the south-east of the existing Galleys Corner junction, with local road links on the south side of the existing A120 to Long Green and Fowlers Farm roundabout, and across the proposed A120 to a new roundabout on the existing A120 north of Cressing Road.
The route is likely to perform in accordance with Expressway safety objectives (provided all elements are provided), which could result in substantial reductions in SRN KSI and casualty rates compared with the existing
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single carriageway route. There are no significant departures from standards which would require mitigation to operate safely.
Initial assessment of the residual existing route and other local roads suggests traffic flows would be reduced significantly by this option (informed by traffic modelling). This would also reduce the casualty rates but mitigation may be required to avoid increased traffic speeds through reduced congestion, resulting potentially in affecting the level of KSIs on the existing A120 route. This option may provide ability to introduce enhanced NMU facilities and deal with severance issues on the existing A120.
This option is the shortest of all routes so would increase casualties by the least amount. However, the section of A12 between the existing A120 junction (J25) and the proposed junction would be subject to an increased traffic flow, with corresponding effect on collisions. In this option, a longer length of A12 is affected, although this is offset by the length of the proposed A120 route being shorter than all other options.
The option is assessed as providing significant safety benefits and slightly more than option 8 owing to the lower number of junctions near Braintree.
Road worker safety on the proposed route would be improved significantly over the existing route by the provision of a range of measures, including concrete barrier, fixed taper points and combined emergency/maintenance bays, which would reduce maintenance interventions and exposure to risk, or ensure they are designed to maximise safety of road workers and road users. Road worker safety on the existing route would not be improved but reduction in traffic flows (levels informed by traffic modelling) might facilitate greater time periods when works could be carried out. Incidents may also be reduced.
Options Assessment – Road User and Road Worker Safety
The overall safety assessment is shown below (note for the option assessment categories refer to Table 39), and is based on existing knowledge of traffic modelling, and a presumption that the improvement scheme would include all Expressway features and operating regime, and that by the time of opening, A12 would be operating with all Expressway features and operating regime.
Core Overall Option Option Option Option Option Programm Scheme 1b 3 4b 8 9a e Objective Objective
a) Improve safety for all road users 3 2 3 3 3 within the A Safe and A120 Serviceable corridor. Network b) Improve safety for all road 3 2 3 3 3 workers within the A120 corridor.
Table 43: Road User and Road Worker Option Assessment
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8.2 Impact during Construction and Operation - Construction (Design and Management) Regulations 2015 This section assesses the health and safety considerations and impacts during construction and use for each option. The observations are based upon Stage 1 Options Identification and safety considerations to be taken through to further project stages during which further design effort will be applied to mitigate hazards. The maintenance considerations are discussed in more detail in section 11, and a number of health and safety risks also relate to the residual maintenance operations depending on the options.
The Scheme falls under the definition of construction work as defined in the Construction (Design and Management) Regulations 2015 (CDM2015). CDM2015 requires a managed approach to the whole life cycle of an asset. This includes management arrangements developed by Essex County Council, resources for the project with the appropriate knowledge, skills and experience and the application of the principles of prevention to the design process to mitigate foreseeable hazards for construction, use and maintenance, so far as is reasonably practicable..
Regulatory Oversight
A short table summarises a basic Regulatory Oversight of the project with respect to Construction (Design and Management) Regulations 2015. The detailed regulatory requirements are outlined in the Regulation and accompanying guidance.
Topic Key designations and features
Definition of The Scheme falls under the definition of construction work as defined in the Construction (Design and Management) Construction Regulations 2015 (CDM2015). Work CDM2015 is the law that applies to the whole construction process on all construction projects, from concept to Application of completion; and describes what each duty holder must or should do to comply with the law to ensure projects are CDM2015 to the carried out in a way that secures health and safety so far as is reasonably practicable. project
Identification and CDM2015 requires for projects involving more than one contractor, the appointment of a Principal Designer and at the appointment of appropriate time before construction commences, a Principal Contractor. For the current stage of the project: main CDM2015 Client Essex County Council dutyholders as project Designers Jacobs UK Ltd progresses Principal Designer Jacobs UK Ltd
Principal Contractor TBC by procurement
Contractors TBC by procurement
Notification of the The estimated scheme scope and programme duration will trigger the requirement for a F10 Notification to HSE project to Health & Safety Executive (HSE)
Table 44: A120 CDM 2015 Summary
General All the options represent a significant undertaking with regards to the scale of the construction effort required to deliver the scheme. The options are more fully described in this report in section 5.
Further safety-related aspects are described in this report in the following sections:
Section 8.1 – Impact on the Road User – Strategic Safety Action Plan
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Section 11 – Maintenance Assessment
Section 5.12.8 – Constructability
Although the high level risks identified for each option are described below, as the scheme progresses to a preferred option the project team will continue to work in accordance with the hierarchy of risk control, seeking to eliminate risks where possible before looking for design mitigation measures. At a future stage, compiling information for the construction team and identifying any design-led site control measures will form a key hazard control task as the project moves from pre-construction to construction.
Option Specific Items (CDM 2015)
Option 3 Option is the partial online option and is therefore the option which has the highest risk created by required traffic management for both road workers and road users during construction. Constraints will be created during construction by the requirement to keep existing routes open to traffic during construction. This could result in restricted space in working areas increasing the risk of road worker / plant conflicts. The phasing for traffic management to create space for construction will be more complex with greater compromises on productivity and the ongoing need to maintain the traffic management to keep the public and workforce from being harmed, although this risk can be mitigated through a combination of TM phasing design and site safety procedures;
Option 3 starts at Galleys Corner and a significant challenge that will be faced for the Galleys corner options will be the phasing / traffic management for the works. Galleys Corner already experiences significant congestion and the client and public are unlikely to tolerate large delays. This could create complex works phases and restricted working space, increasing the risk to road workers and road users due to complex traffic management layouts. At future design stages further work on the works phasing and TM design will be undertaken in conjunction with the permanent works design to simplify construction. The solution envisaged at this time, keeping the A120 at-grade, will help with this.
From the C2 responses a number of clashes with statutory undertakers have been identified at Galleys Corner including medium pressure gas mains and underground HV cables which will require careful management during construction. The degree to which the construction envelope conflicts with utility services will be at a maximum on the online sections as the majority of services will lie close to the route.,
Option 3 crosses the River Blackwater and floodplain to the north of Bradwell. This is a significant river viaduct crossing of around 190m which will create risks associated with working at height as well as over water. There is also an existing subway at Galleys Corner which have to be extended and two crossings of the existing A120, one to the west of Dolphin Pub on the western edge of Bradwell likely to require a temporary diversion of the A120 and one to the east of Coggeshall to the east of the B1024. On the Coggeshall Bypass there is a Robins Brook reinforced concrete box culvert and a pedestrian underpass which are to be extended to suit the widened carriageway. These structures are likely to require some form of demolition which will create risks not present in the other options which are predominately being constructed on green field sites. These existing A120 crossings will require traffic management and will result in a concentration of plant.
Although presenting more detail on hazards than the level of design permits, it could be identified that the additional structures elements including the need for demolition increases the necessary concentration of plant and personnel required for the construction of highway structures in this location, increasing the potential hazards arising during construction. This could create an increased risk to both road workers and road users in particular potential exposure to asbestos and silica dust, work at height, failure of temporary works, manual handling, plant-person conflict and accidental incursions into the works by the road users.
As well as the high level construction risks detailed above, option 3 is also the option with the greatest number of mainline geometrical departures which could have an impact on operational safety and may increase the risk to road users. The opportunities to maximise design-led hazard mitigation are reduced by the constraints of the existing alignments. Adding further restriction to this aspect will be existing boundary restrictions, thereby creating construction phase working space constraints and the potential for permanent works to retain some of the departures from standard that currently affect the route. These features are likely to be reduced in overall
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impact on the scheme by the future design effort and construction phase safe systems of work but, may not be removed entirely for example where a departure from standard cannot be designed out because of the existing alignment.
Option 3 is the only option which has intermediate junctions; Doghouse Road, Colne Road and Colchester Road. The majority of road accidents occur in the vicinity of junctions and therefore Option 3 may have a greater level of collisions during operation due to the spacing of the junctions, than the other options.
Notwithstanding all of the above whilst the risks associated with Option 3 are considered qualitatively to be slightly greater than other options, due to the comparison made between online and offline construction, the risks are not considered especially complex or unusual and so this is not by itself considered a conclusive discriminator between options in the overall project context at this stage. The overall approach to the project must be seen in the context that all the options involve significant construction activity that will be carried out by a carefully selected and competent supply chain using largely tried and tested techniques and materials.
Option 4B
Option 4B starts at Galleys corner and therefore will have the same risks associated with the Galleys Corner junction as detailed for Option 3.
Option 4B crosses through Bradwell Quarry in the middle of study area. As detailed in section 5.12.2 the restoration methodology implemented by the Quarry will result in poor ground conditions that will require remediation. The current restoration methodology prior to the availability of ground investigation data is based on excavating the restored overburden down to London Clay and then replacing the overburden with standard MCHW compaction.
This will involve an extensive earthworks activity requiring a large quantity of heavy plant and equipment, generating a hazardous environment. . There would also be risks associated with slope stability (associated both with excavation and the temporary material stockpile) which would create risks for workers, this risk should be mitigated by undertaking ground investigation at later project stages. It is hoped that at later project stages a combined ground improvement solution of partial excavation and dynamic compaction could remove the need for a large proportion of the required earthworks at Bradwell quarry.
Option 4B crosses the River Blackwater to the east of Bradwell Quarry requiring a viaduct of around 200m which will require a large concentration of plant as well as creating risks associated with working at height and adjacent to / over water. In addition either side of the river there is likely to be soft alluvium which could cause adverse settlement, however ground investigation carried out at later stages should help to eliminate / mitigate this risk.
Option 1B Option 1b commences on the A120 Braintree Southern Bypass, leaving the existing A120 alignment to the east of Notley Road bridge heading to a new grade separated junction to the north of Tye green.
Option 1B requires a large structure across the River Brain (100m) which will involve work at height over water. In addition this structure will require a concentration of plant in this location.
Option 1B is required to cross under the Braintree – Whitham Branch railway line which is likely to require a more complex structure than is required for other options such as a jacked box which is likely to create higher construction risks than the other structures on the scheme.
Option 1B also passes very close to the Braintree sub-station and as a result requires the diversion of some 132kV overhead cables including the relocation of pylons. This work will need to be carefully managed due the risk of working adjacent to electricity as well as dismantling the pylon structures. There is also a localised high pressure gas main affected by Option 1B.
Option 1B then passes through the Quarry and over the River Blackwater attracting similar risks to those described in Option 4B.
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Option 8
Option 8 is similar in nature to option 1B with the River Brain junction (River Brain Viaduct, Braintree Branch Line structure, HV cables and localised high pressure gas main). Option 8 also passes through Bradwell Quarry, although for a shorter distance than for options 1B & 4B.
Option 9B
Option 9B commences at Galleys Corner attracting the traffic management hazards and concentration of utility service diversions as described for option 3. Option 9B encroaches on Bradwell Quarry as attracting hazards as described in option 4B though similar to option 8, this encroachment is not as extensive as options 1B & 4B.
A12 Tie in – All options
All A120 options under consideration tie into the A12 either at J23 or J24A. The A12 RIS 1 project is being developed ahead of the A120 and therefore by the time A120 opens the A12 in these locations will have been widened from 2 to 3 lanes (whether online or offline). The junctions at the A12 will require significant volumes of imported fill transported on the A12 requiring a large number of vehicle movements. Further design effort has the potential to help reduce this burden on the network but the issues associated with extensive earthworks and heavy vehicles remains. The junctions will also require bridges that will cross the Great Eastern Mainline Railway, the existing A12 and the new A12 (if offline) which require significant planning and traffic management to construct safely. Notwithstanding the post-construction operation of the route, the extensive offline sections do offer the advantage previously stated of allowing the contractor greater control of the construction site operations, lower interaction with the travelling public with reduced potential for conflicts and reduced traffic management burden on the project. As stated previously, this by itself is not conclusive as there are wider benefits locally and nationally from considering how each option meets the overall objectives defined for the scheme.
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9. OPERATIONAL ASSESSMENT
9.1 Introduction
This section reviews at a high level the results of the traffic modelling against the capacities of links and junctions to make an assessment of the operation of the scheme.
9.2 New A120 and junctions
9.2.1 Opening year (2026) daily flows on the new A120 DMRB TA46/97 “Traffic Flow Ranges for Use in the Assessment of New Rural Roads” table 2.1 gives a range of opening year economic flow ranges.
The flow range for a new D2AP road is given is 11,000 to 39,000.
The opening year (2026) AADT flows on the new A120 for each option, taken from Appendix D of the Traffic Forecasting Report, are shown in the table below.
AADT for each option Junction to Junction section Direction 1b 3 4b 8 9b
Eastbound 19924 0 20073 22086 22325 A120 New Alignment from Galleys Corner Westbound 20898 0 21014 21910 22247 to A12 Total 40822 41 08 7 43996 44572 Eastbound 21882 A120 New Alignment from Galleys Corner Westbound 21866 to Bradwell Total 43748 Eastbound 23033 A120 New Alignment from Bradwell to Westbound 24594 North Coggeshall Total 47627 Eastbound 22478 A12 New Alignment North Coggeshall to Westbound 24674 East Coggeshall Total 47152 Eastbound 24533 A120 New Alignment from East Westbound 24608 Coggeshall to A12 Total 49141
Table 45: Opening year (2026) AADT flows
It can be seen therefore that the anticipated opening year flows are either just above the above the upper bound for D2AP for most options, whilst Option 3 is some distance above.
As TA46/97 notes (para 1.5 therein refers), however, these are only flows for initial economic purposes and not an actual measure of capacity. They do, however, confirm that the flows justify at least provision of a D2AP section. Hence for operational assessment an alternative method of calculation is considered more appropriate.
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9.2.2 Design year (2041) peak hour flows on the new A120
Tables 6-6 to 6-8 in the Stage 1 Traffic Forecasting Report give hourly flows in the design year (2041) for the route options for the AM, Inter-peak and PM peak hours respectively.
A120 AM Peak Hour Flows Junction to Junction section Direction 1b 3 4b 8 9b 2161 2099 2038 2067 1931 A120 Braintree Bypass, Great Notley to Eastbound Galleys Corner/New Interchang Westbound 3271 3176 3176 3125 2988 A120 New Alignment from Galleys Corner Eastbound 1336 1328 1677 1687 to A12 Westbound 1674 1670 1758 1744 A120 New Alignment from Galleys Corner Eastbound 1502 to Bradwell Westbound 1946 A120 New Alignment from Bradwell to Eastbound 1577 North Coggeshall Westbound 2140 A12 New Alignment North Coggeshall to Eastbound 1610 East Coggeshall Westbound 2133 A120 New Alignment from East Eastbound 1761 Coggeshall to A12 Westbound 1781
Table 46: Design year (2041) A120 AM Peak hour flows
A120 PM Peak Hour Flows Junction to Junction section Direction 1b 3 4b 8 9b 3393 3394 3307 3192 3064 A120 Braintree Bypass, Great Notley to Eastbound Galleys Corner/New Interchange Westbound 2551 2417 2382 2240 2054 A120 New Alignment from Galleys Corner Eastbound 1872 0 1872 1953 1955 to A12 Westbound 1686 0 1685 1859 1889 A120 New Alignment from Galleys Corner Eastbound 2069 to Bradwell Westbound 1716 A120 New Alignment from Bradwell to Eastbound 2124 North Coggeshall Westbound 1843 A12 New Alignment North Coggeshall to Eastbound 2003 East Coggeshall Westbound 1879 A120 New Alignment from East Eastbound 2079 Coggeshall to A12 Westbound 1989
Table 47: Design year (2041) A120 PM Peak hour flows
TA46/97 Appendix D gives a method for calculating the free-flow capacity of a traffic lane, this being:
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Capacity = A-B*PkHr HGV, where for an all-purpose road A = 2100, B=20
Taking 10.1% as the typical value for the A120 based on data in the Traffic Forecasting Report , gives a lane capacity of 1898 vehicles per lane per hour, hence for a dual two lane section a total capacity of 3796 vehicles per hour. This is the free-flow capacity without considering the influence of junctions.
In contrast, the standard for grade separated junctions TD22/06 “Layout of Grade Separated Junctions” uses a flow of 1600 vehicles per lane per hour for an all-purpose road. (The equivalent capacity for a motorway is 1800 vehicles per lane.)
Comparing the forecast flows against these capacities it can be seen that:
• Across all the options, the mainline of the new A120 between Braintree and the A12 is well within capacity – flow ranging from 1328 vehicles to 2140 vehicles max and hence (using the TA46/97 capacity) a flow capacity ratio between 35% and 56%
• The section of the A120 immediately west of the scheme is approaching or marginally over-capacity in the design year - the maximum option peak hour flow of 3394 vehicles per hour representing flow/capacity ratio of 85% (using the TA40/97 capacity) to 106% (using TD22 values). Above ratios of flow/capacity of above 85% degradation in service and congestion is likely to start to occur.
• The adoption of expressway standards in particular technology such as monitoring and variable message signs may help increase capacity above the 1600 vehicles per lane per hour value. It is clear, however, that this section will be under some operating stress and this aspect will be considered further as the scheme is developed.
9.2.3 Weaving between junctions on the new A120 All the route options, except 3, do not have any intermediate junctions.
For options 1b and 8, whilst there are two junctions at the west end of the scheme, the River Brain junction and the Tye Green junction as the River Brain junction is a limited movement junction with no east-facing sliproads there is no weaving section here and the successive diverges / merges are over 1km apart so there is not anticipated to be any operational issues here. Similar applies to Options 4b and 9a with the new sliproads at B1018 Millennium Way, with west facing sliproads only, and the new Galleys Corner junction.
For options 1b and 8 , as noted in the options description text, the River Brain junction is around 1km from the preceding junction west on the A120, the London Road junction. This weaving section may just be below the 1km minimum as per TD22/06 “Layout of Grade Separated Junctions”, requiring a departure. As discussed in section 5.8 the initial layout for the River Brain junction has been arranged to maximise the weaving length provided.
When combined with the high traffic volumes in this section some operational difficulties could occur – this will be further assessed in future stages.
For option 3, in general the intermediate junctions are over 2km apart and hence in accordance with TD22/06, the exception being the B1024 Colne Road junction and the Colchester Road junction, which are just under 1km apart, however the weaving flows are anticipated to be very light. Should this route option be chosen, the design of this section would be given particular consideration, noting as well the difficulties with the Colne Road junction mentioned in the options description section.
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9.2.4 Junctions on the new A120 At this stage, the nature of the development of design and the traffic model is such that detailed analysis of the capacity of the junctions on the scheme is neither possible nor appropriate. Based on some initial indications of traffic flows from the modelling some general observations can be made, however.
River Brain junction (Options 1b and 8) – flows leaving/joining the A120 here are dependent on how much flow from the A131 north direction transfers from the existing route via Galleys Corner roundabout to the new link from the A131 to the Tye Green junction (the “Galleys Corner Bypass”). In the design year it is anticipated that congestion at the existing Galleys Corner roundabout will discourage traffic from using the original route hence traffic using the River Brain junction is anticipated to be limited to the order of 250-350 vehicles in the peak hour in each direction. The initial envisaged layout, particularly the 270 degree loop on the westbound merge sliproad is then anticipated to be suitable for such flows. (Were traffic such as to require a two lane sliproad then the loop arrangement could be less suitable with operational difficulties.)
Tye Green Junction (Options 1b and 8) – assuming transfer of traffic as above the junction is anticipated to see flows in the order of around 1400 vehicles joining/leaving the A120 to the west, much lower flows to the east 200-400 vehicles. It anticipated that with suitable development of the design the initial layout of a dumbbell grade-separated junction should suffice.
Millennium Way Slips (Options 3, 4b and 9a) – between 550 and 800 vehicles are anticipated to use this junction in the peak hour in each direction. At this stage no issues with its operation are anticipated.
Galleys Corner Junction (Options 3, 4b and 9a) – the principal flow here is from the A131 to the A120 westbound and vice-versa with up to around 1000 vehicles hour making this movement. Subject to design development the capacity and operation of the envisaged dumb-bell layout is anticipated to be satisfactory. The proposed bridge over the A120 west of the junction between Cressing Road and Ashes Road provides a separate route for local traffic and thus diverts a smaller, but significant, 400-600 vehicles from the main Galleys Corner junction, keeping that for strategic traffic.
Doghouse Road, Colne Road, Colchester Road junctions (Option 3) – these are the intermediate junctions on option 3. They are anticipated to have low traffic flows in the range 100-350 vehicles joining or leaving A120 in each direction. There are thus not anticipated to be any capacity issues with these junctions. The layout of the Colne Road junction is anticipated to be governed by spatial constraints, which may result in a lower than ideal standard of provision – a compact grade separated junction is currently envisaged. Notwithstanding the low traffic flows, the operation of such a junction and its proximity to the Colchester Road junction will need careful consideration should this route option be progressed.
New A120 Junction – A12 Junction 24a (Options 1b, 3 and 4b) – indications are that flows of up to 1800 vehicles per hour will use the north facing slips, the principal traffic movement, and very small flows 100 vehicles or so an hour for the south facing sliproads. Potentially, depending on analysis of the dumb-bell roundabout capacity, a free-flow “trumpet” arrangement may be more appropriate, to reduce queues on the sliproads.. The detail of the junction here, in any case, is heavily dependant on the chosen solution for the A12 widening which is not known at this time.
Re-built A12 junction 23 (Options 8 and 9a) - indications are that flows of up to 1300 vehicles per hour will use the north facing slips, the principal traffic movement, and smaller flows 400 vehicles or so an hour for the south facing sliproads. This should be within the capacity of the currently envisaged dumb-bell arrangement but this will be reviewed as the design progresses.
9.3 Adjacent sections of A12
9.3.1 Design year (2041 peak hour flows on the new A120
Given that the scheme ties-in to the A12 consideration has been given to the operational effect of new A120 in the immediate vicinity of the tie-in.
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As noted in section 5.5, Highways England are planning to widen the A12 to three lanes in each direction in the sections that the A120 options tie-in to.
The peak hourly flows on the A12 taken from tables 6-6 and 6-8 in the Stage 1 Traffic Forecasting Report.
A12 AM Peak Hour Flows Junction to Junction section Direction 1b 3 4b 8 9b 4619 4836 4620 4308 4280 A12 Between New Interchange, North Eastbound Keveldon and Mark Tey Jct 25 Westbound 5083 5106 5083 5009 4988 3429 3507 3420 4308 4280 A12 Between North Kelvedon Jct 24 and Eastbound New Interchange Westbound 3553 3683 3501 5009 4988 Eastbound 2880 3028 2884 3848 3818 A12 from Jct 24 to 23 Westbound 3296 3522 3294 4850 4829
Table 48: Design year (2041) A12 AM Peak hour flows
A12 PM Peak Hour Flows Junction to Junction section Direction 1b 3 4b 8 9b 5815 5884 5820 5297 5273 A12 Between New Interchange, North Eastbound Keveldon and Mark Tey Jct 25 Westbound 4282 4516 4295 3937 3938 4133 4254 4130 5297 5273 A12 Between North Kelvedon Jct 24 and Eastbound New Interchange Westbound 2791 2916 2792 3937 3938 Eastbound 3683 3926 3689 4983 4948 A12 from Jct 24 to 23 Westbound 2350 2555 2354 3586 3586
Table 49: Design year (2041) A12 PM Peak hour flows
For the three lane widened A12, the capacity will range between 4800 vehicles and 5694 vehicles per hour, depending on how this is derived as discussed above in section 9.2.2.
It can be seen that:
• The options with the tie-in north of Kelvedon (1b, 3 and 4b) generate the largest flows on the A12, with Option 3 by a small margin the critical one.
• For these three options using the largest calculated capacity this is marginally exceeded in the design year with a flow/capacity ratio of 103% and this ignores the effect of weaving traffic (see below) between these junctions. Thus, without further lane capacity there is very likely to be congestion, operational and safety issues in this section.
• For the options that tie-in south of Kelvedon (8 and 9b) the flows on the A12 are not as high with flow/capacity ratio of 87.5% in the area immediately north of the new A12 (junctions 23 to 24), only slightly above the 85% threshold.
The A12 flows will need to be re-assed in conjunction with the traffic modelling to be undertaken for the A12 scheme.
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9.3.2 Weaving between junctions on the A12 For the route options that join the A12 between Kelvedon North (J24) and Marks Tey J25), options 1b, 3 and 4b, weaving between the new junction for the A120 and the adjacent junctions on the A12 is an issue.
The proposals for the junctions on the A12 are being developed as part of that widening scheme and the locations are not fixed. At the time of writing, based on the developing proposals for the A12:
• The proposed location for the new A120 junction will give a weaving length of around 1.1km to the preceding junction (J24) on the A120
• The proposals for the A12 widening scheme show a new junction 25 being provided, south of its existing location. This then gives a weaving length between the junctions of 1.1km.
Both weaving lengths are just above the minimum 1km minimum given in TD22/06. As proposals for both schemes develop maintaining the minimum distance will need to be kept in mind.
With the options that tie in south of Kelvedon, options 8 and 9a, the junctions are 4km apart and so more than 2km maximum length as per TD22/06 where weaving effects apply.
A calculation of the lanes required to provide sufficient capacity for weaving using the methodology given in TD22/06 has been undertaken, the results of which are shown below:
A12 Direction A120 A120 A120
Junction Option 1b, 4b Option 3 Option 8b, 9b AM PM AM PM AM PM
J23-24 NB Not applicable as > 2km between SB junctions
J24-24a NB 2.2 2.8 2.4 2.9
SB 2.3 1.8 2.7 2.0
J24/J24a- NB 3.3 4.2 3.4 4.4 Not applicable as > J25 2km between junctions SB 4.2 3.1 4.4 3.2
Table 50: Number of lanes required for weaving on the A12
Weaving between the Kelvedon North (J24) and the new A120 (J24a) junction is therefore not an issue, the proposed three lane A12 providing sufficient capacity. Between the new A120 junction (J24a) and the Marks Tey junction (J25) , however, the weaving calculation indicates that three lanes on the A12 will not be sufficient and a fourth lane in both directions would be needed in this section.
The provision of such a lane would ultimately be part of the A12 project and the matter has been brought to the attention of that scheme for consideration in the future as that scheme develops. In the meantime, the works cost of providing an extra lane in each direction on the A12 between the junctions has been allowed for in the A120 costings.
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This area would be given particular consideration as the design of both the A120 and A12 schemes progress, including the respective traffic modelling.
9.4 Local roads
The local road diversions, away from the junctions, are generally simple replacements for existing rural roads, many being single track, with only a couple of minor junctions affected by the proposals. There is not anticipated to be any capacity or operational issues with these realignments.
9.5 Conclusions The following conclusions can be made:
• The new A120 itself between Braintree and the A12 will operate well within capacity and should have no operational capacity issues
• The existing A120 west of the scheme will be at or close to capacity and there is the potential for some congestion and reduced performance. Whilst not part of the improvement scheme, the implications of this constraint will be considered further as the design and traffic modelling progresses.
• For options tie-ing in between Kelvedon North and Marks Tey it is probable that a fourth lane to provide capacity for weaving traffic will be needed between the new A120 junction and Marks Tey and allow safe and efficient operation. (This works cost of this fourth lane has already been allowed for in the A120 scheme costings.)
• The indications at this time there are not anticipated to be any capacity or operational issues with the location/general design of junctions. The Colne Road junction will need particular consideration given its constrained location, however.
Overall the scheme is anticipated to provide sufficient capacity, operate satisfactorily and fulfil the relevant scheme specific objectives.
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10. TECHNOLOGY ASSESSMENT
All options of the proposed A120 are proposed to be designed as an expressway. The design standards for Expressways are currently under development as detailed in the Implementation of New Standards PCF product (Document Reference: B3553T41-JAC-HGN-00-REP-C-0007).
The current available design guidance for expressways is included in the Expressway Technical Note (Document Reference HE_DES_V1.0_20160309). This technical note indicates that A120 between the A131 and M11 J8 is designated as a current, planned and potential expressway. In addition the A12 between M25 J28 and A14 J55 is also designated as a current, planned and potential expressway. The section of the A120 between the B1417 to Marks Tey is designated as an option for further expressway.
As the A12 in the location that all A120 options will tie into will be designed to expressway standards there is therefore the possibility to create a high quality route from the A12 to the M11 and Stansted airport.
10.1 Options Design Implications for the Utilisation of Technology in terms of:
10.1.1 ITS systems - Traffic loops, VMC, CCTV etc.
The proposed provision of technology on the A120 is based on the expressway core requirements which are expected to include:
• Motorway Incident Detection and Automatic Signalling (MIDAS) – It is expected that this would be radar based to avoid the need for loops in the carriageway. The system would detect speed, headway, and occupancy of traffic within a zone and provides the prompt for the system to them automatically set the speed limits on safety grounds.
• Comprehensive CCTV Coverage – It is expected that Pan-tilt-zoom (PTZ) cameras will be provided linked to the Regional Control Centre (RCC)
• Variable Message Signs (VMS) – These message signs would display incident and traffic management details. It is anticipated that these signs would be located on MS4s and co-located at Emergency Refuge Areas (ERAs)
• Variable Mandatory Speed Limits (VMSL) – The ability to display variable speed limits will be used when there is an abnormal situation such as incidents, or if advice is being given to drive slower in bad weather, and may also be used during maintenance.
10.1.2 Communications Network
• It is a core Expressway Requirement that all technology assets shall be integrated into Highway England’s traffic management system (CHARM) which is currently under development. The objective of the CHARM project is to specify, install and migrate to a new, integrated traffic management system capable of managing current and planned capacity of the network and with provision to interface with emerging technologies.
• It is expected that a longitudinal ducted network will be required linking to the National Roadside Telecommunication Service (NRTS) in order for them to provide a communication network which will service the technology proposed.
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11. MAINTENANCE ASSESSMENT
11.1 Impact of Operational Regime The proposed scheme would be to an Expressway standard, currently defined in Highways England’s Technical Note issued in 2015. An Interim Advice Note containing further details is planned for issue. The operational regime would include a number of elements designed to facilitate future maintenance. There would also be a five year maintenance free period after completion.
Civils Infrastructure
Key elements include:
• Concrete barrier – this would virtually eliminate repair resulting from collisions, reducing exposure to risk for workers and road users, and increasing network availability. • Geometric Standards – the use of high standard geometry would facilitate safer operation of routine maintenance and temporary traffic management *** • Structures – New structures would be provided at Galleys Corner and the intersection with the A12 (New grade separated junctions * and ***), the River Brain*, the River Blackwater ** (viaduct), the Great Eastern Main Line, the Braintree Branch Line *, side road bridges, minor structures for Non-motorised User crossings, and various culverts. Safe access will be designed to facilitate maintenance of this infrastructure. • Pavement – pavement would be maintained using standard methods, and would require lane closures. • Drainage – Safe access would be provided to enable required maintenance of drainage facilities including channels, gulleys, attenuation and pollution control measures. • Soft estate and fencing - Safe access would be provided to enable required maintenance of aspects these elements.
* Additional grade separated junction west of River Brain, River Brian Bridge and Braintree Branch Line Bridge required, Options 1b and 8 only ** The River Blackwater Bridge not required, options 8 and 9a *** Additional grade separated junctions required at Bradwell, Colne Road and Coggeshall (East) and single carriageway local access road between Bradwell and Coggeshall – Option 3 only.
Technology
Key elements include:
• Maintenance Access – provision of emergency bays combined with maintenance access bays and technology cabinets, and variable message signs would facilitate safer maintenance of assets. • MIDAS Detectors – Above ground detection would reduce maintenance requirements on the carriageway, minimising loop detector repair, traffic management interventions and exposure to risk. • Temporary Traffic Management – Rotating Temporary Traffic Management Signs (ROTTMS) would be provided based on designed fixed taper points to facilitate placing of TM signing without the need for road workers to work from or within the carriageway to place the signs. The signs could be turned on and would provide further protection to road workers engaged in placing cones and lamps from vehicles. • Variable Message Signs – these can be used to further enhance advance warning of road works and implementation of temporary speed limits.
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11.2 Maintenance Strategies Initial design hazard elimination and risk reduction has been commenced, which includes elements related to operational and maintenance safety. The development of the maintenance strategy would have the Principles of Prevention at its core using the hierarchy of control – Eliminate, Reduce, Investigate, Control (ERIC) for risk reduction or elimination (). This may be achieved through various means, and particularly through avoiding the hazard altogether through design wherever possible by considering occupational and system safety throughout the lifecycle of the asset and minimising exposure to risk. Elements may include:-
• Combining cyclic activities (such as routine street lighting repair, drainage, litter picking) in shared traffic management, subject to appropriate risk assessment of adjoining activities, to minimise network occupation, maximise network availability and minimise periods of exposure to risk for road workers and road users. • Use of materials and products which minimise required maintenance interventions. • Scheme design which minimises maintenance interventions required (for example, drainage). • Off highway maintenance access, where appropriate, from the local road network. • Safe access routes along the highway and to assets such as structures and roadside equipment. • Facilitation of design areas of hardened verge for maintenance vehicle access and to facilitate mobile lane closures where appropriate. • Use of technology to improve our safety in design approach to improve monitoring, durability and ease of access. • Strategic diversion routes would be developed in collaboration with the Police and Operations Directorate.
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12. ENVIRONMENTAL ASSESSMENT
12.1 Introduction
This chapter presents a summary of the potential environment effects that may arise from the A120 Scheme. This has been based on the results of the PCF Stage 1 Environmental Assessment Report. Environmental assessment will continue to be carried out in later stages of PCF Stage 2. Baseline environmental conditions are described in Section 5 of this report.
A summary of the key points arising from the evaluations is provided below for each topic. This includes a commentary on any likely notable difference in the effects of the options.
12.2 Air Quality and Carbon Emissions
For carbon emissions, the A120 scheme is likely to lead to a marginal deterioration in emissions (i.e. greater amount of emissions) based on the increases in distance travelled with the A120 scheme. In addition, the A120 scheme is likely to generate more vehicles traveling on the network and/or vehicles rerouted onto the new route alignment. The options will also lead to great NOx/NO 2 levels to receptors along the options. Therefore, all of the options were considered to overall have a slight adverse effect on air quality; however, these effects are not considered significant.
The scheme will also lead to a slight beneficial effect on receptors along the A120 and in the south east of Braintree by relieving congestion and reducing the amount of traffic which would use this road.
In terms of differences between the options, options 4B and 9A were found to have the lowest number of human exposure receptors within 200 metres compared to other options.
12.3 Cultural Heritage
All of the route options are considered to have potential significant adverse effect – mitigation may be possible . All of the routes are likely to affect the setting of a number of Grade II listed buildings and may affect unknown buried archaeological remains. Key differences between the routes are:
• Options 3, 8 and 9A may have potential significant adverse effects – mitigation may be possible on the setting of Grade II* listed buildings.
• Options 4B and 9A may have potential significant adverse effects – mitigation may be possible on the setting of Glazenwood House and Garden (non-designated historic garden).
• Options 8 and 9A may have potential significant adverse effects – mitigation may be possible on the setting of scheduled monuments.
• Options 4B, 8 and 9a may disturb known archaeological remains considered to be of moderate significance. This is considered a significant adverse effect – mitigation may be possible , depending on the exact location and nature of the buried remains.
12.4 Landscape
All of the route options are considered to have potential significant adverse effects – mitigation may be possible . Realigned side roads, overbridges and NMU routes have the potential to give rise to adverse landscape and visual effects. However these effects are similar for all options. All of the routes will have the following potential effects:
• Effects on the setting and views of listed buildings.
• Views from where the route rises on embankments to cross the A12 and railway line.
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• Views from residential receptors.
• Are likely to sever medium sized arable fields and hedgerows.
The following are differences between the routes:
• Option 1B crosses both the River Brain and River Blackwater valleys on embankment and both railways lines. It also severs common land but avoids substantial areas of woodlands.
• Option 3 crosses the River Blackwater south of Sisted and Robins Brook north of Chelmsford, which are considered particularly sensitive. The option would affect the setting of the Sisted Conservation Area. This option would lead to the loss of existing established highway vegetation, potentially opening up views for local residents.
• Option 4B may have effects on the setting of Glazenwood Park and Garden.
• Option 8 crosses both the River Brain on embankment and both railways lines.
• Option 9A follows the shortest route and is considered least at odds with field pattern, landform, existing woodland and settlements.
12.5 Nature Conservation
All of the routes are likely to have the following potential significant effects – mitigation may be possible :
• All of the options may have effects on European sites through the hydrological connectivity of rivers and channels and through potential effects on migratory birds.
• All of the routes may lead to the loss and degradation of habitat and fragmentation of species of high/national importance, medium/county importance. These effects are considered potentially significant adverse - mitigation may be possible. The routes will lead to the fragmentation of some linear habitats. Notable species include Barbastelle bats and birds of national importance. A number of medium importance species may have potentially significantly adverse effect – mitigation may be possible. These include great crested newts, dormouse and water vole.
• All routes may have potential significantly adverse effect – mitigation may be possible effects on riparian environments, rivers and ponds.
The following differences have been noted between the routes:
• Options 1B, 3 and 4B will potentially have potential significant adverse effects – mitigation may be possible , on non-statutory sites, such as local wildlife sites, adjacent to the route.
• Option 8 and 9a will only have slight adverse effects on non-statutory sites, such as local wildlife sites, adjacent to the route.
• Route 3 will affect the least amount of habitats of high/national importance.
• Route 4b will affect the least amount of pond habitats (medium importance).
• Route 8 will have slight adverse effects on habitats of low/local value, while the other options will have potentially significant adverse effects – mitigation may be possible.
It should be noted that the current impact assessment is based on an ecological phase 1 survey. Presence surveys would be required to establish the presence of species and determine measures that would best minimise adverse impacts and provide residual beneficial effects
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12.6 Geology and Soils
All of the route options are considered to have a potential significant effects – mitigation may be possible . All of the options will lead to impacts on secondary A aquifers and secondary (undifferentiated) aquifers. Impacts may occur from potential mobilisation of contaminated land and from construction activities. All of the routes will lead to dewatering activities for cuttings, which may have effects on domestic abstractions with varying distances from the option. In addition, all of the routes will cross land with soils considered of grades 2 and 3 agricultural land (best and most versatile soils).
The following differences have been noted between the routes:
• Route option 1B and 8 crosses both the River Brain and the River Blackwater.
• The main lines of options 3, 8 and 9A only cross the major watercourse of River Blackwater (considered of high sensitivity for geology and soils). However, the junctions associated with these routes may also cross the River Brain. The options also cross numerous smaller watercourses of varying sensitivity. This may potentially increase the risk of degradation of water quality.
• The main lines of options 1B and 4B cross the major watercourses of River Blackwater and River Brain (considered of high sensitivity for geology and soils). The options also cross numerous smaller watercourses of varying sensitivity. This may potentially increase the risk of degradation of water quality.
• Options 1B, 3 and 4B will lead to the removal of a licenced abstraction well.
• Options 1B, 4B, 8 and 9A will cross areas of potential high risk of contamination.
• There is a high risk of instability where options 1B, 4B, 8 and 9A cross Bradwell Quarry.
12.7 Materials
The scheme will lead to overall potential significant adverse effects – mitigation may be possible for all of the route options. For materials usage, all of the options would result in potential significant adverse effects – mitigation may be possible . The majority of waste generated from the A120 Scheme would be from demolition and construction waste. Potential impacts are primarily associated with the production, movement, transport and processing of wastes on and off-site. It is considered that there is adequate waste management capacity in the area; therefore the significance for waste effects for all options has been assessed as slight adverse .
12.8 Noise and Vibration
The A120 scheme will lead to an overall significant beneficial effect with regards to noise for all routes. This is due to a reduction on traffic flow along the A120 and includes approximately 100 residential properties in NIA’s. Significant noise benefits are also likely on properties in NIA’s along the Braintree bypass. Significant beneficial noise effects are also expected for properties in the areas not within NIA’s along the existing A120. A relatively small number of sensitive receptors have the potential to experience significant adverse noise effects. However, the significance of these effects may be reduced through mitigation. These receptors are located in the rural areas between Braintree and the A12. Significant vibration effects are not expected from the operation of the proposed routes. The key differences between the options are:
• For two of the options, Option 3 and 8, potential significant effects were noted which may not be possible to mitigate for two properties. For Option 1B, potential significant effects which may not be possible to mitigate are expected for one property. Further assessment will be required on the potential effect on these two properties when traffic modelling data is available.
• Routes 1B and 3 will provide significant beneficial effects to a great number of properties within NIA’s adjacent to the existing A120.
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• Option 1B will have potential significant adverse effects – mitigation may be possible on a greater number of groups of properties.
It should be noted that the noise assessment was undertaken on a qualitative basis and a quantitative assessment utilising traffic modelling should be undertaken to confirm the outcomes.
12.9 People and Communities
All of the route options will lead to an overall potential significant adverse effect – mitigation may be possible . However, there would be some beneficial effects associated with the A120 scheme including the creation of construction jobs, use of local services and suppliers, improvements in access and relieving congestion and economic benefits from reduced journey times.
All of the options will have potentially significant adverse effects – mitigation may be possible from temporary disruption during construction to NMUs, permanent loss of best and most versatile agricultural land, disruption to local business and cumulative effects with other planned schemes.
The following differences have been noted between the routes:
• Route 3 may lead to slight beneficial effects from improvements in connectivity for NMU’s across the existing A120.
• Route 3 will create temporary disturbance for access for the highest amount of schools out of the options.
• Routes 1b, 3 and 4b will lead to the permanent land take of the western edge of the Marks Tey Point-to- Point course and a potential motor cross track.
• Option 3 and 9a would require the demolition of Cressing Lodge Farmhouse.
• Option 1b and 8 will lead to permanent land take of two areas of registered common land (it should be noted that the common land status for Lanham Green has not been confirmed).
12.10 Road Drainage and Water Environment
All of the route options will lead to overall potential significant adverse effects - mitigation may be possible . These were noted where the routes passed over significant watercourse, such as the Rivers Brain and Blackwater, Domsey Brook and Robin’s Brook, with regards to increasing flood risk and on geomorphology and degradation of water quality. In addition, a number of minor water courses, lakes and ponds are located along the routes which may have potential significant adverse effects – mitigation may be possible .
The following differences have been noted between the options:
• Options 1B and 8 cross both the River Brain and River Blackwater which would engross on flood zone 3 and have potential impacts associated with sediment input and/or changes to drainage. The other options only cross the River Blackwater.
• Options 1B, 3 and 4B affect Domsey Brook. Options 3 effects both Domsey Brook and Robins Brook with regards to potential degradation of geomorphology and water quality from sediment input. These are considered high value receptors.
• Routes 1B and 4B will affect Bradwell Quarry Lake, with regards to degradation to geomorphology and water quality.
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12.11 Overall Conclusions
For noise and vibration, significant adverse effects – not possible to mitigate , have been noted for two properties on options 3 and 8 and for one property on option 1B. However, this is based on qualitative results which will be refined once traffic modelling is available. Further opportunities for mitigation for these properties will be explored when considering further route design. Given that the A120 scheme will remove traffic from the existing A120, there is likely to be an overall beneficial effect from the scheme for noise and vibration. Air quality along the A120 will benefit from the same effects of reduced traffic. However, some slight adverse effects are expected for air quality along the offline options.
For cultural heritage all of the route options are considered to have potential significant adverse effect - mitigation may be possible . All of the routes are likely to affect the setting of a number of Grade II listed buildings and may affect unknown buried archaeological remains. Several of the routes also affect the setting of scheduled monuments and Grade II* Listed Buildings, but again mitigation may be possible.
The most notably effects on landscape are expected to be where the options could conflict with the existing landform, in particular where they cross river valleys, such as the River Brain and River Blackwater, or where the options cross the A12 and railway. It should be noted that all of the route options cross at least one river, and all cross the A12 and railway to tie into the A12. In addition, routes 1b and 8 cross areas of Common Land.
A number of effects ranging from slight adverse to potential significant adverse effect – mitigation may be possible have been noted for junctions and road crossovers. Further opportunities will be sought during the design process, such as moving junctions and cross overs and different design options to reduce these effects.
All of the options would lead to the loss of habitats and isolation for species of high/national importance, including bats and birds and for species of medium and low importance, such as great crested newts, dormouse, badgers and otters. Further surveys would be required to confirm the presence or absence of species. There may be adverse effects on European Sites from pollution via hydrological connectivity and disturbance to migratory birds. However, all of these effects have the potential to be mitigated.
In summary, all of the options result in broadly similar level of effects, with no overall potential significant adverse effects identified at this stage of the assessment, which can’t be mitigated. Benefits include improvement in air quality and noise along the existing A120 and likely economic benefits from economic uplift.
However, further investigation through data collection traffic modelling assessments, desk studies and site surveys (particularly with regards to ecology) is required to fully ascertain the effects and mitigation, if required.
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13. ASSESSMENT SUMMARY This section contains the scheme appraisal summary tables which aims to provide a concise, across-the-board overview of the impacts of a scheme option which takes account of all the economic, social, environmental and financial impacts of an intervention as set out in the Treasury Green Book.
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Table 51: Option 1B Appraisal Summary Table
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Table 52: Option 3 Appraisal Summary Table
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Table 53: Option 4B Appraisal Summary Table
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Table 54: Option 8 Appraisal Summary Table
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Table 55: Option 9A Appraisal Summary Table
It should be noted that the Appraisal Summary Table (AST) environmental scoring shows the post mitigation effects, whilst the EAR describes the effects prior to mitigation. The table below shows the link between the two scoring methods.
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Score 6 point effect scale Post mitigation effects
Significant adverse effect - not possible to Significant adverse 1 mitigate Potential significant adverse effect – Moderate adverse 2 mitigation may be possible Slight adverse effect - Effect not significant Slight adverse 3 with typical mitigation. 4 Slight beneficial - Effect not significant Slight beneficial 5 Significant beneficial effect Significant beneficial 0 No effect No effect
Table 56: Link between pre and post environmental mitigation scoring in EAR and AST
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14. PROGRAMME
The A120 Braintree to A12 public consultation is planned to launch in January 2017 and will be complete by March 2017. A report will then be prepared on the public consultation summarising the responses received. This public consultation report will be reviewed and summarised in the Scheme Assessment Report (SAR) which is expected to be prepared by July 2017.
The purpose of the scheme assessment report is to provide a summary of the Technical Appraisal Report and the Report on Public Consultation and to recommend a preferred option. The A120 Braintree to A12 scheme is not currently in the RIS 2 programme and the SAR will be submitted to HE as part of the RIS 2 application document. Following the submission of the SAR the project is expected to progress to SGAR 2 in December 2017 (date to be confirmed).
Following completion of SGAR 2 it is expected that there will be a 6 – 9 month gap whilst a decision is made on whether or not A120 will join the RIS 2 programme. Assuming that the scheme enters the RIS 2 programme then Stage 3 is likely to commence around September 2018 lasting until December 2019. Stage 4 featuring the statutory process (Development Consent Order) is likely to run from December 2019 to July 2021 with stage 5 (detailed design) commencing in July 2021 running until April 2022. Assuming a 6 month period from issue of tender to award then construction could commence at the end of 2022, which will depend on the procurement method. The length of construction is dependent on which option is chosen, however assuming a 3 year construction period the scheme is expected to open by 2026.
The programme detailed above is highly indicative and is based on the A120 entering the RIS 2 programme, as well as the assumption that the A12 scheme is delivered prior to the A120, as the A120 relies upon the A12 being widened from 2 to 3 lanes.
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15. CONCLUSION OF RECOMMENDATIONS
15.1 Option(s) for Public Consultation
Based on the assessments in this report, all five route options are valid solutions and based on the assessment conducted will fulfil the scheme objectives, these options being:
• Option 1b – central off-line route commencing at River Brain finishing between J24 and J25
• Option 3 – part on line, northern route finishing between J24 and J25
• Option 4b – central off-line route commencing at Galleys Corner and finishing between J24 and J25
• Option 8 – southern off-line route commencing at River Brain and finishing at A12 J23
• Option 9a – southern off-line route commencing at Galleys Corner and finishing at A12 J23
Whilst there are differences identified between the routes in the assessments none represents key discriminators such as to reject a route. As noted in section 7 indications from the ongoing economic analysis are that the BCRs of all options are relatively close and the adjusted BCRs will all fall into at least the medium value for money category. Hence on economic grounds all five options represent valid solutions.
15.2 Preferred Solution
Noting the issues above, the relative close comparison between options, it is not possible to identify a preferred solution at this time. The five viable options for the scheme should be taken forward to Public Consultation in the PCF Stage 2 and the preferred route will be determined at the end of Stage 2.
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16. DETAILED COST ESTIMATE
The cost estimates for all options are detailed within the Options Estimate PCF product (Document Ref: B3553T41-JAC-HGN-00-RP-C-0001) which should be referred to for further details.
To build up the works costs a material take off for all options was conducted and then priced using rates from historical projects as well as from SPONS estimating handbook, using rates from Q1 2016. Also included in the works costs are the Statutory Undertakers costs, accommodation works costs and landscaping costs which have all be calculated as a percentage of the works costs. As well as the percentage factor for STATs an extra allowance of £10M for options 1B and 8 was provided due to the clash with the O/H HV pylons associated with the Braintree substation.
Also included in the works costs is the remediation of Bradwell Quarry which as detailed is section 5.12.2 is priced on the assumption of excavating the restoration overburden down to London clay and then compacting this overburden in layers to provide a suitable foundation for the A120.
Preparation costs have also been included in the scheme costs estimates which include design costs, DCO legal support, employer’s costs and third party costs including network rail. Environmental mitigation costs have been included at this stage although mitigation has not yet been designed so it is based on similar values from historical schemes. A significant cost which will be incurred by the scheme is Lands costs which will include land purchase and part 1 claims, at this stage the lands costs have been estimated using a percentage of scheme value based on similar historical schemes. Supervision costs have been included as a percentage of the works costs using historical scheme values.
VAT is only recoverable for highways works within the existing highway boundary. The large majority of works on A120 are outside the highways boundary and therefore the scheme will not be able to recover VAT, this adds another 20% to the scheme cost.
A risk allowance and optimism bias factor of 44% has been used at this stage. TAG Unit A1.2 table 8 recommends 44% optimism bias to be applied to roads projects at this stage of development. Clause 3.5.9 states that with sufficient evidence it is possible to deviate from these factors. The A120 is further advanced than most schemes at stage 1 and so the project team feel it is justified to reduce the optimism bias level down so that the combined risk and optimism bias is a value of 44%. At later stages of project development a quantified risk assessment will be conducted to obtain risk values. Inflation was also applied to all options from Q1 2016 to Q3 2024 which is the expected mid-point of construction. The level of inflation has been assumed at 3.5% per annum up to 2020 and 4.0% per annum after 2020 for the basis of this estimate, which is based on current available information from RICS.
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