A4 Bristol to East Keynsham Corridor Study - Option Assessment Report

Prepared for West of England Combined Authority

May 2018

1 The Square Temple Quay Bristol BS1 6DG

Document history

A4 Bristol to East Keynsham Corridor Study Option Assessment Report

This document has been issued and amended as follows:

Version Date Description Created by Verified by Approved by 1.0 Jan 2018 Draft for client review VE DJL DJL (chapters 1 – 7) 2.0 March Draft for client review VE DJL DJL 2018 (inc EAST assessment) 3.0 May 2018 FINAL DL DL

Contents

Section Page Acronyms and Abbreviations ...... i 1 Introduction ...... 1 1.1 Purpose of this report ...... 1 1.1.1 Description of the Study ...... 1 1.2 Strategic Context ...... 3 There are several important strategic policies that have informed the development of the proposals described in this report. These are identified below...... 3 1.2.1 National Planning Policy Framework ...... 3 1.2.2 Joint Spatial Plan and Local Plans ...... 3 1.2.3 Joint Local Transport Plan ...... 4 1.2.4 Relationship with Transport Topic Paper ...... 5 1.2.5 Approach to Options Assessment Reports ...... 5 1.2.6 Structure of this report ...... 5 2 Understanding the Current Situation ...... 7 2.1 Description of the Study Area ...... 7 2.1.1 General...... 7 2.1.3 Constraints - General ...... 8 2.1.4 Physical constraints ...... 8 2.1.5 Environmental constraints ...... 9 2.1.6 Non-car modes...... 10 2.2 Current Vehicle Demands ...... 11 2.3 Existing Transport Problems ...... 13 2.3.1 Wider connectivity challenges in Keynsham ...... 14 3 Understanding the Future Transport Situation ...... 16 3.1 Future Land Uses and Policies ...... 16 3.1.1 Committed developments ...... 16 3.1.2 JSP proposals...... 17 3.2 Future Changes to the Transport System ...... 19 3.2.1 Keynsham Transport Strategy...... 19 3.2.2 West of England Joint Transport Study ...... 21 3.3 Future Traffic Demand ...... 22 3.4 Future Transport Related Problems ...... 24 3.4.1 Base-line Modelling (2029) ...... 24 3.4.2 Connectivity from the North Keynsham SDL ...... 24 3.4.3 Requirement for improved connectivity from Broadmead to A4 ...... 25 4 Need for Intervention, Objectives and Geographical Scope ...... 26 4.1 Summary of Current and Future Problems, Impacts and Outcomes ...... 26 4.2 Scheme Objectives and Outcomes ...... 26 4.3 Measures for Success ...... 26 5 Generating and Initial Sifting of Options ...... 28 5.1 Approach to Option Generation ...... 28

SECTION PAGE 5.2 Results of Option Generation ...... 28 5.3 Approach to Initial Option Sifting ...... 30 5.4 Results of Initial Sifting ...... 31 6 Option Development and Assessment ...... 35 6.2 Option Development ...... 36 6.2.1 Option 2A - ‘Pixash to Avon Mill Lane’ ...... 36 6.2.2 Option 2C - ‘Pixash to new junction on A4175’ ...... 38 6.2.3 Option 3A - ‘A4 new junction to Avon Mill Lane’ ...... 40 6.2.4 Option 3C - ‘A4 new junction to new junction on A4175’ ...... 41 6.3 Construction Access ...... 42 6.4 Traffic Modelling ...... 43 6.5 Cost Estimating and Economic Assessment ...... 46 6.5.1 Cost Estimating ...... 46 6.5.2 Economic Assessment ...... 47 7 TAG Appraisal Stage 1- Early Assessment and Sifting Tool Tables ...... 48 7.1 Introduction ...... 48 8 Early Assessment and Sifting Tool - Supporting Information ...... 53 8.1 Strategic Case ...... 53 8.1.1 Scale of Impact ...... 53 8.1.2 Fit with wider transport and government objectives ...... 54 8.1.3 Fit with scheme objectives ...... 55 8.1.4 Key uncertainties ...... 56 8.1.5 Degree of consensus over outcomes ...... 57 8.1.6 Summary of strategic case ...... 57 8.2 Economic Case ...... 57 8.2.1 Economic growth ...... 57 8.2.2 Carbon emissions ...... 60 8.2.3 Local environment ...... 60 8.2.4 Socio-distributional and regionals impacts ...... 63 8.2.5 Well being ...... 64 8.2.6 Value for Money ...... 64 8.2.7 Summary of economic case ...... 65 8.3 Managerial Case ...... 65 8.3.1 Implementation Timetable ...... 65 8.3.2 Public acceptability ...... 65 8.3.3 Practical feasibility ...... 65 8.3.4 Quality of Supporting Evidence ...... 66 8.3.5 Key risks ...... 67 8.3.6 Summary of management case ...... 67 8.4 Financial Case ...... 67 8.4.1 Affordability ...... 67 8.4.2 Capital Cost (£m) ...... 67 8.4.3 Revenue costs ...... 68 8.4.4 Cost Profile ...... 68 8.4.5 Overall cost risk and other costs ...... 68 8.4.6 Summary of financial case ...... 68 8.5 Commercial Case ...... 68

IV CONTENTS Section Page 8.5.1 Procurement ...... 68 8.5.2 Flexibility of option ...... 69 8.5.3 Funding sources ...... 69 8.5.4 Income generation ...... 69 8.5.5 Summary of commercial case ...... 69 8.6 Summary ...... 69 9 Recommendation ...... 70

Appendices Appendix A - Constraints Plans Appendix B - ‘Long List’ Highway Option Alignment Drawings Appendix C - Geology and Ground Conditions: Desk Study Appendix D - Environmental Report Appendix E - FRA/Drainage Report: Stage 1 Appendix F - Services Drawings Appendix G - Structures Assessment Appendix H – Long List Option Sifting Tables Appendix I - Option Design and Engineering Appendix J - Traffic Modelling Appendix K - Cost Estimates and Economic Assessment

Tables Table 1.1: JLTP4 Objectives Table 1.2: Structure of this report Table 2.1: 18-hour flow data 0400-2200 (MCC Figures) Table 2.2: Matched LV Movements 0400-2200 Table 4.1: Measures for Success Table 5.1: Long list of options Table 5.2: Long list of schemes considered Table 5.3: Sifting outcome Table 6.1: Network performance outputs, morning peak period (07:00 – 10:00) Table 6.2: Network performance outputs, evening peak period (15:00 – 19:00) Table 6.3: Modelled traffic volumes (two-way), morning peak period (07:00-10:00) Table 6.4: Modelled traffic volumes (two-way), evening peak period (15:00-19:00) Table 8.1: Scale of Impact Table 8.2: Fit against transport and government objectives Table 8.3: Fit with Scheme Objectives Table 8.4: Degree of consensus over outcomes Table 8.5: Economic growth Table 8.6: Carbon Emissions Table 8.7: Local environmental impacts Table 8.8: Natural and Urban Environment

SECTION PAGE Table 8.9: Social distributional impacts Table 8.10: Regional impacts Table 8.11: Impacts on well being Table 8.12: Value for Money Categorisation Table 8.13: Public acceptability Table 8.14: Practical feasibility Table 8.15: Affordability Table 8.16: Capital cost (£m) Table 8.17: Revenue cost (£m) Table 8.18: Cost Risk Table 8.19: Summary of how the scheme options meet the five cases

Figures Figure 2.1: Left: Broadmead Lane railway bridge (source: Google Maps) Figure 2.2: Right: Pixash Lane railway bridge crossing Figure 2.3: Public Rights of Way in Keynsham (source: OutdoorsWest) Figure 2.4: Keynsham ANPR survey locations Figure 3.1: Keynsham Spatial Strategy (Core Strategy 2011-2029) Figure 3.2: JSP Key Diagram, showing SDL locations Figure 3.3: Potential transport infrastructure improvements (source: Volume 3 of the Place Making Plan for BANES) Figure 3.4: Current and proposed bus, pedestrian and cycle routes (source: Volume 3 of the Place Making Plan for BANES) Figure 3.5: South East Area (Bath to Bristol) Figure 3.6: Complementary JTS proposed schemes

Acronyms and Abbreviations

BANES Bath and North East Somerset DfT Department for Transport DMRB Design Manual for Roads and Bridges GBATS Greater Bristol Area Transport Model GWML Great Western Main-Line HE Highways England JLTP3 Joint Local Transport Plan 3 for West of England JSS Joint Spatial Strategy JTB Joint Transport Board JTS Joint Transport Study LEP Local Enterprise Partnership LTB Local Transport Body NPPF National Planning Policy Framework OAR Option Assessment Report PRoW Public Rights of Way SAC Special Area of Conservation SDI Social and Distributional Impacts SDL Strategic Development Location SEP Strategic Economic Plan SGC South Gloucestershire Council SOBC Strategic Outline Business Case SSSI Sites of Special Scientific Interest WebTAG DfT online Transport Analysis Guidance WECA West of England Combined Authority WoE West of England

1 Introduction 1.1 Purpose of this report This is the Options Assessment Report for the A4 Bristol to East Keynsham Corridor Study, which is referenced as ‘Road 13’ in the West of England Joint Transport Study (WoE JTS), dated July 2017 (Appendix A). It describes the process of analysing the transport challenges, defining corridor- specific objectives and identifying and assessing potential interventions to tackle these challenges. This report builds upon the findings of the previous Joint Transport Study1, a high-level strategic study that responded to the current and future connectivity challenges in the West of England and identified strategic mitigation in support of the Strategic Development Locations proposed in the Joint Spatial Plan. Additional work is required to support the progression of the schemes through the Local Plan making process and Department for Transport funding pipeline. The West of England authorities have therefore commissioned further technical studies to examine in more detail the transport impacts of the Strategic Development Locations, and to develop the strategic transport schemes to allow consultation to take place through the Local Plan process on potential site selection, route alignment, costs and deliverability. This technical work is documented in a series of Options Assessment Reports (OARs). These OARs have been structured to comply with best practice for transport studies, as documented in the Department for Transport’s Transport Analysis Guidance (WebTAG)2. Specific guidance for transport studies is documented in the unit titled ‘The Transport Appraisal Process’3, which sets out a stepped process to analysis of the issues and identification and assessment of potential options. Whilst the OARs represent a significant step forward in the development of the strategic transport proposals, they still represent an early stage of option development and assessment. Further scheme development and public consultation will be undertaken during 2018 following the publication of the OARs, as part of the Local Plan process. This document sets out the OAR for the A4 Bristol to East Keynsham Corridor. It is designed to follow the best practice in WebTAG and therefore provides an objective assessment of the transport challenges and identifies appropriate solutions to the challenges in the corridor. 1.1.1 Description of the Study Figure 1.1 shows the extent of the study area to the north of Keynsham, much of which is north of the Great Western Main-Line (GWML) as indicated. Most of the land is low-lying agricultural land. However, there is some existing industrial land-use to the west of the main sewage treatment works. Between the GWML and the A4 Bath Road is the Ashmead Trading Estate, with existing access across the railway line to the north provided by an underbridge at Broadmead Lane and a Grade 2 Listed over-bridge at Pixash Lane.

1 https://www.jointplanningwofe.org.uk/consult.ti/JTSTransportVision

2 https://www.gov.uk/guidance/transport-analysis-guidance-webtag

3 https://www.gov.uk/government/publications/webtag-transport-appraisal-process

The link road forms part of the assessment of options for the ‘A4 Bristol to East Keynsham Arterial Corridor’. This comprises the following scheme components:  Avon Mill Lane to A4 Link: A new road alignment through the ‘Broadmead Pennisula’ to the north of the Great Western Main-Line (GWML) connecting Avon Mill Lane at its western end with the A4 Bath Road at its eastern end; and  Keynsham Railway Station Improvements.

Figure 1.1: Study Area Location Plan

The link road scheme will include an improved crossing over/under the GWML railway, with the route enabling traffic to divert around Keynsham town centre, whilst providing access to the proposed strategic development at North Keynsham. The improvements to Keynsham Railway Station are expected to consist of localised improvements to cycle parking and other NMU facilities. Indeed, the JTS (Appendix A) under ‘Rail 2’ makes no specific mention to Keynsham, but refers instead to ‘Service Improvements and Station Upgrades’ at a WoE level. In view of this, separate consideration of options for improving accessibility to Keynsham Station does not form part of this OAR. However, as options for the link road include consideration of the A4175/Avon Mill Lane junction close to the station, the opportunities for improving pedestrian access from the Picnic Area car park and the shared use footway along the A4175 to the north have been considered as part of the Link Road work. The currently proposed pedestrian/cycle linkage improvements between Somerdale and the station are also duly considered in achieving a ‘fit’ with these.

SECTION 1 – INTRODUCTION 1.2 Strategic Context There are several important strategic policies that have informed the development of the proposals described in this report. These are identified below. 1.2.1 National Planning Policy Framework The National Planning Policy Framework (NPPF)4 sets out the Government’s planning policies and how these are expected to be applied. The Framework must be taken into account in local plans and is a material consideration in planning decisions. It must therefore be reflected in developing the transport proposals in this study. In particular:

 Paragraph 162 states that local planning authorities should work with other authorities and providers to assess the quality and capacity of infrastructure for transport and its ability to meet future needs.  Paragraph 165 highlights the importance of the economic, social and environmental dimensions of sustainable development and that significant adverse impacts on any of these dimensions should be avoided.  Paragraph 182 refers to the examination of Local Plans and states that the local authority should submit a plan for examination which it considers is sound, namely that it is positively prepared, justified, effective and consistent with national policy. This OAR demonstrates how the proposed A4 Bristol to East Keynsham Corridor will meet the requirements of the NPPF. Section 1.4 below explains how the tests of soundness (from NPPF Paragraph 182) are demonstrated through this report. 1.2.2 Joint Spatial Plan and Local Plans The West of England Joint Spatial Plan (JSP)5 is a prospectus for sustainable growth to help the region meet its housing and transport needs for the period to 2036. The JSP is the first such joint planning approach in the UK, which takes into account cross-boundary effects within the West of England. The JSP sets out the policies and principles that have been applied in identifying future housing and employment needs and the most sustainable locations for future development. The JSP is a strategic statutory Development Plan Document (DPD) for the West of England. It is being prepared jointly by, and will cover, the four Unitary Authorities of Bristol, Bath and North East Somerset, North Somerset and South Gloucestershire. On adoption as a DPD it will carry full weight in the planning system and provide the higher level strategic planning policy framework for each authority’s new Local Plan for the period 2016 to 2036. The JSP supports the delivery of 82,500 new jobs and 105,600 new homes by 2036, of which 61,400 homes are existing commitments and the JSP makes provision for 44,200 new homes. Of this, 17,300 homes will be in Strategic Development Locations (SDLs), 16,600 through Urban Living, 6,900 through small windfall sites and 3,400 in non-strategic growth. The SDLs will be brought forward as allocations through each authority’s new Local Plan. New site- specific allocations and policy designations in Local Plans will need to be in conformity with the JSP. Work has commenced on preparing the four Local Plans based on the current JSP proposals, although these will not be finalised until after examination and adoption of the JSP. Local Plan

4 https://www.gov.uk/government/publications/national-planning-policy-framework--2

5 https://www.jointplanningwofe.org.uk/consult.ti/JSPPublication/consultationHome

consultations will be undertaken throughout 2018 and will include the proposed transport schemes required to support delivery of the Local Plan allocations, including the SDLs. This OAR demonstrates how the proposed transport interventions in the A4 Bristol to East Keynsham Corridor will support the proposed Local Plan allocations and meet the principles of sustainable travel described in the JSP. 1.2.3 Joint Local Transport Plan The current Joint Local Transport Plan (JLTP3) covering the period 2011 to 2026 sets out the following five key transport goals for the region (see Table 1.1 below for more detail):  Reduce carbon emissions;  Support economic growth;  Promote accessibility;  Contribute to better safety, security and health; and  Improve quality of life and a healthy natural environment. The West of England local authorities are currently in the process of developing a new Joint Local Transport Plan (JLTP4) for the area. This will cover the period to 2036 and will therefore align with the Joint Spatial Plan. The JLTP4 is currently being prepared, with consultation scheduled to take place during summer 2018. The JLTP4 will consider the recommendations of the Joint Transport Study and develop a long-term transport policy framework that is consistent with the Joint Spatial Plan. It will develop a long-term investment programme shaped by a set of objectives that build on the JLTP3 goals. Goals Sub-goals Reduce greenhouse gas emissions Reduce carbon Provide a resilient and adaptable transport network emissions Promote walking, cycling, and public transport Implement the programme of major transport schemes Tackle congestion

Support economic Promote use of alternatives to the car – walking, cycling, public transport and smarter choices growth Support delivery of and access to houses and jobs Increase capacity and reliability of transport networks Maintain, manage and make best use of transport assets Reduce the number of road casualties Contribute to better Encourage more physically active travel – walking, cycling and public transport safety, security and health Implement Air Quality Management Areas Improve personal security on the transport network Improve access to health and employment

Promote Assist regeneration of deprived areas in Bristol and Weston-super-Mare accessibility Implement the Rights of Way Improvement Plans Improve access for rural residents and people with mobility difficulties Enhance the public realm Minimise the impact on the natural and historic environment Improve quality of life and a healthy Enhance the journey experience natural environment Promote better access to leisure activities and the countryside Support Bath World Heritage site and Areas of Outstanding Natural Beauty

SECTION 1 – INTRODUCTION

Table 1.1: JLTP3 Goals

This OAR will provide an overall assessment of how the schemes proposed for the A4 Bristol to East Keynsham Corridor will address the JLTP3 goals set out above. 1.2.4 Relationship with Transport Topic Paper A Transport Topic Paper has also been produced, which provides supporting transport evidence for the JSP. The Transport Topic Paper addresses the overall strategic transport issues in the West of England, considers the impacts of proposed development in the JSP, and presents the overarching transport infrastructure programme to meet future needs. The Transport Topic Paper integrates infrastructure identified from this OAR for the A4 Bristol to East Keynsham Corridor into the overall JSP infrastructure programme, and demonstrates that this programme will mitigate the impacts of the Strategic Development Locations, Urban Living and wider growth in the JSP. 1.2.5 Approach to Options Assessment Reports The Options Assessment Reports (OARs) demonstrate that sufficient consideration has been given to the case for intervention, assessment of options, technical feasibility, costs, benefits, impacts, potential strength of business case and affordability of the proposed transport schemes. The OARs have been structured and prepared in accordance with the good practice set out in WebTAG6. These documents are not formal business cases: these will be prepared at a later date following consultation on the scheme options. In following the WebTAG approach, the OARs do not specifically consider the mitigation impacts of the transport interventions in respect of the JSP and Local Plan proposals, although the case for intervention is partially built around this. The mitigation impacts are assessed separately in the Transport Topic Paper, whilst the focus in the OARs is on development of business cases based as much as possible on committed levels of development, as required by WebTAG. This is in order to demonstrate that the transport interventions are fundable and could be progressed in advance of the developments proposed in the JSP and Local Plans. Further sensitivity testing including the JSP and Local Plan proposals will be carried out in preparation for the Local Plan consultations . 1.2.6 Structure of this report Table 1.2 sets out the structure of this report. The table also shows which of the four NPPF tests of soundness (refer to Section 1.2) are addressed in the evidence in each chapter. NPPF Tests of Soundness Consistent Chapter Contents of chapter Positively Justified Effective with nat. prepared policy Description of study area Understanding the Yes 2 Current travel demand (evidence - - - current situation Existing transport problems on needs) Future land uses and policies Understanding the Changes to the transport system Yes 3 (evidence - - - future situation Future travel demand on needs) Future transport problems Yes Summary of problems and issues Yes (objectives Need for Scheme objectives and outcomes (objectives 4 - - consistent for future intervention Measures for success with network) Geographical scope policies) 5 Generating and Approach to option generation Yes Yes - Yes

6 https://www.gov.uk/government/publications/webtag-transport-appraisal-process

sifting options Approach to option sifting (options to (assess (sifting to Results of option sifting address and sift take Approach to next steps objectives) options) account of policies) Yes Yes Approach to option development Yes Option Yes (appraisal (appraisal Options development (assess 6 Development and (analysis of of costs, to take technical Options assessment each mode) benefits, account of Assessment feasibility) Conclusions impacts) policies) Yes Yes Yes Yes (DfT (appraisal TAG Appraisal Early Assessment and Sifting Tool (appraisal (assess EAST tool 7 of costs, against technical considers Stage 1 Tables benefits, objectives) feasibility) policy) impacts) Yes Yes Yes Yes (DfT (appraisal Early Assessment (appraisal (assess EAST too 8 Supporting Information of costs, against technical considers and Sifting Tool benefits, objectives) feasibility) policyl) impacts) Table 1.2: Structure of this report

2 Understanding the Current Situation 2.1 Description of the Study Area 2.1.1 General Keynsham is a town located between Bath and Bristol which had a population of 15,533 in the 2011 census. The town is served by Keynsham railway station on the London to Bristol and Bristol to Southampton lines. The A4 Bath Road runs through the town centre but much of the traffic is now carried by the Keynsham Bypass, which was constructed in 1964 and runs north of Keynsham, from Saltford to Brislington in Bristol. Consultation on the Core Strategy Spatial Options document (November 2009) highlighted a number of key issues facing Keynsham, including:  Recent and future job losses;  Desire for town centre regeneration;  Affordable housing shortage;  Ageing population;  Traffic congestion;  Limited public transport;  Insufficient emphasis given to protecting Keynsham’s heritage; and  Ongoing threat of development in the Green Belt. 2.1.2 Land use, socio-economic and demographic context Keynsham is predominantly residential, with some employment and supporting retail and education land uses. The adopted Core Strategy for BANES states that “Keynsham currently has a balance between numbers of resident workers and jobs but experiences significant in and out-commuting in light of the mismatch of resident workforce and types of available jobs.” The town is surrounded by the Bath and North East Somerset Council Green Belt, which limits the extent of development within the town. The Area Profile for Keynsham7 indicates that the town has:  Higher proportions of people aged 65 years and over than the BANES and England and Wales averages.  Lower proportions of unemployed people than the England and Wales average.  Lower proportions of people using public transport to get to work than the England & Wales average. In 2006 BANES Council published ‘The future for Bath and North East Somerset’ which described Keynsham as having been ‘coasting’ since the 1970’s. In the meantime, improvements in nearby competing centres, especially in Bristol, have resulted in Keynsham losing ground economically.

7 http://www.bathnes.gov.uk/services/your-council-and-democracy/local-research-and-statistics/wiki/keynsham-forum-area 7

2.1.3 Constraints - General Constraints plans of the North Keynsham area through which the link road alignment would need to pass are included in Appendix A. These include the following:  General Constraints: including landfill areas, greenbelt, planned development (B&NES Core Strategy/Place Making Plan); sites of Nature Conservation Interest and other locally important designations;  Flood Zones;  Listed Buildings and Scheduled Monuments; and  International Biodiversity Designations. The constraints plans show that a significant part of the area falls into Flood Zone 3, including a localised area around the Broadmead Lane under-bridge to the south of the railway line. This is linked to the watercourse to the south, which is culverted under the railway line just east of the Broadmead Lane arch bridge. There are also areas of former and existing landfill, the most significant of which lies immediately north of the main sewage treatment works and denoted as ‘Open Mosaic Habitat’. This is a former landfill site which was subject to a Geotechnical Investigation in February 2009. The results of this and implications for any road alignment traversing it to connect with Avon Mill Lane is considered and discussed in the Geological Desk Study undertaken for this OAR. The constraints plans also identify existing ‘committed’ areas for development in the B&NES Core Strategy, namely the strategic employment site allocation on land to the east of Pixash Lane around Worlds End Lane and the residential development land at East Keynsham to the south of the A4 Bath Road (Policy KE3A). The former will be a key constraint on acceptable link alignment and bridge over points to the GWML to the east of Pixash Lane. 2.1.4 Physical constraints As shown in the constraints plans, the physical geography of the town is influenced by the rivers Avon and Chew which converge to the north of the town at Somerdale. With respect to the Broadmead area, accessibility is constrained by the River Avon, but particularly by the GWML. There are currently only three existing crossings of the railway between Broadmead and the A4 Bath Road, and all are poor. The first is a road bridge under the railway at Broadmead Lane, the second a narrow road bridge over the railway at Pixash Lane and the third another narrow underbridge accessed via Unity Road and serving the main sewage works and a small industrial estate. The former two are shown in Figure 3.1 and Figure 3.2 below. The underbridge off Unity Road is of the same form as that at Broadmead Lane.

Figure 2-1: Left: Broadmead Lane railway bridge (source: Google Maps) Figure 2-2: Right: Pixash Lane railway bridge crossing The existing masonry arch bridge at Broadmead Lane has a span of 3.65m and a headroom of 3.35m (11’ 0”) between the chord lines which are unusually close together at a distance of 1.8m apart.

Several replacement options were investigated by Tony Gee & Partners in 2004 as part of a feasibility study into improved access to the north side of the railway line to serve a possible waste terminal. With deference to this previous feasibility study, the options for Broadmead Lane bridge enhancement have been re-evaluated as part of the options work described later in this OAR. At present, this ‘single track’ arch structure provides access to a small trading estate on the north side of the bridge adjacent to the River Avon, and is thus relatively lightly trafficked. It would be unsuitable in its current form (without widening) to form any main part of a future ‘through’ link between the A4 Bath Road and the A4175 Keynsham Road. Notwithstanding the limitation on link capacity due to ‘shuttle’ one-way working, there is no footway provision through the arch requiring pedestrians to walk along the carriageway edge. Pixash Lane Bridge shown in Figure 2.2 is a masonry arch of 9.144m (30’) span and is Grade 2 listed, entry number: 1409197, dated 18 July 2012. This serves Avon Valley Adventure and Wildlife Park, and is of single lane width with a crest vertical alignment unsuitable for long vehicles. As will be seen from the photograph, the forward visibility across the crest is also substandard (DMRB). As with the Broadmead Lane under-bridge, this bridge would be unusable as part of the link road, whilst in this case it’s Grade 2 listed status would prevent any consideration of in-situ widening/re-construction. In developing options for the link road, it is clear that both existing structures will impose limitations on the size of the construction plant which is able to access the north side of the railway. This is discussed in the ‘Structures’ technical paper appended to and referenced later in this OAR. The other physical constraints are essentially linked to the capacity of the surrounding highway network, and the ability to deliver new or modified terminal junctions to the link road which cater for existing ‘committed’ growth and that arising from the proposed SDL at North Keynsham. Particular issues are likely to be as follows:  A4175/Avon Mill Lane junction: This existing major-minor ‘priority’ junction already suffers from queuing problems in the weekday peak hours. As part of the Somerdale development, a s278 scheme for proposed widening and introduction of traffic signal control is secured. However, previous assessment work suggested this would only just cope with existing ‘committed’ development. In developing options in the OAR, this junction has been specifically examined to identify the scope for a ‘step-change’ improvement in capacity; and  A4/Pixash Lane junction: Notwithstanding the issues with the bridge over the railway, the capacity of this major-minor ‘priority’ junction with the A4 could also be a constraint on the future use of a new ‘through’ route if using Pixash Lane at its eastern end. Examination of existing conditions along the part of Pixash Lane to the south of the railway also shows that there is currently a significant level of on-street parking associated with employees/users of the Ashmead Trading Estate. As part of the options work, the layout changes needed to the A4/Pixash Lane are considered. Suffice to say, using this part of Pixash Lane as part of a ’through’ link would require restrictions on current on-street parking. It is noted from the Place Making Plan that vehicular access to the strategic employment land to the east of Pixash Lane is to be taken off Pixash Lane, which will add to traffic pressures at the junction with the A4 Bath Road. 2.1.5 Environmental constraints 2.1.5.1 Water Environment To the west of Broadmead Lane most of the study area is within Flood Zone 2. Both sides of Broadmead Lane south of the railway and the north of the lane around Broadmead Lane Industrial Estate are designated as Flood Zone 3. 2.1.5.2 Landscape and Ecology Each of the potential route alignment options fall within the Bath and North East Somerset Green Belt. The National Planning Policy Framework allows for local transport infrastructure to be located within Green Belt where it can demonstrate a requirement for a Green Belt location and does not

conflict with the purposes of including land in the Green Belt. The study area is outside the Cotswolds Area of Outstanding Natural Beauty but is visible from it. The area contains a number of character areas with woodland at the western end, around the SD Smith site and open fields in the centre and east. The main (northern) area of the site has a relatively open and tranquil character due to its physical and visual separation from the built settlement of Keynsham and the mid to long distance views of the Cotswolds. At the east, the railway lies in a cutting and provides less visual severance. Due to the flat topography, views within the site are relatively short, constrained by trees and hedgerows, but are set against a backdrop of the hills of the Cotswolds and Kelston Roundhill. Land slopes are more pronounced at the North Eastern corner close to the railway river crossing making the land here more visible and exposed. At present, there is a notable landscape ‘gap’ between the settlements of Keynsham and Saltford with only a small cluster of housing on the A4. This gap is considered to be an important factor in the setting of the two settlements and is highly desirable to retain. The site is visible from the Cotswolds and is considered to be part of a continuous swathe of open countryside from the Avon Valley towards the hills. The eastern and riverside areas of the site are considered to be the most visible. North of the railway and south of Avon Valley Farm at the approximate location of the Option 3 railway crossing there is 0.6ha of conifer woodland which is listed in the National Forest Inventory. North of Avon Valley Farm Business Park (at the east of this site) and either side of Avon Mill Lane at its junction with Keynsham Road (west of the site), there is 1.3 ha and 0.6 ha respectively of deciduous woodland as listed in the Priority Habitat Inventory. The land either side of the north end of Broadmead Lane is Coastal and floodplain grazing marsh as listed in the Priority Habitat Inventory. There is also Priority Habitat Inventory 0.15ha traditional orchard south of World’s End Lane. The site falls within Site of Special Scientific Interest (SSSI) Impact risk zones for Stidham Farm SSSI (east of the study area) and Cleeve Wood Hanham (north west of the study area). There are Public Rights of Way (PRoWs) to the east of the site linking Saltford to Avon Valley Farm and Pixash Lane. A Strategic Planning Framework for North Keynsham has been produced by Arup on behalf of Bath and North East Somerset Council. This provides further details on the site characteristics of the SDL. 2.1.5.3 Culture and Heritage Several Grade II listed structures are found in the study area, including the railway crossings at Pixash Lane Bridge, Avon Mill Lane Bridge and the River Chew Bridge as well as Avon House, the Old Brassmill and Brassmill cottage to the west of the study area around Avon Mill Lane. There are a number of heritage sites with Historic Environment Records (HER), notably some Roman finds at Avon Valley Park. There are a small number of buildings with notable character at Broadmead Lane Industrial Estate and Avon Valley Farm. 2.1.6 Non-car modes There are numerous Public Rights of Way (PRoW) in Keynsham, as shown in Figure 2.3 below. There are no National or Regional Cycle Routes within the study area.

Figure 2-3: Public Rights of Way in Keynsham (source: bathnes.gov.uk)

There are a number of existing bus routes which serve North Keynsham. The closest bus stops to the study area are located on the A4 Bath Road, with a number of services calling including Service X39 connecting the area to Bristol City Centre, and the A4 connecting the area to Bristol Airport. A number of bus services call at Keynsham railway station, including service 19A to Cribbs Causeway and service 17 to Southmead Hospital. Keynsham Railway Station has at least an hourly service in each direction Monday and Saturday, with roughly a two-hourly service on Sunday. The majority of services are a combination of two hourly Weymouth trains and two hourly Southampton trains eastbound and an hourly service to Bristol and Gloucester in the other direction. In addition, there is one direct service from London Paddington on Monday to Friday. 2.2 Current Vehicle Demands Traffic counts and ‘Automatic Number Plate Recognition’ (ANPR) surveys were undertaken around Keynsham on Thursday 14th July 2016 as part of a CH2M study into ‘Managing Keynsham’s Future Growth’ on behalf of B&NES. This provided a comprehensive picture of ‘through’ and other movements across a cordon designed to capture all vehicles entering/leaving the town. The five cordon points were as follows:  Sites 1 and 2: A4175 Bristol Road - just east of Durley Hill mini-roundabout junction  Sites 3 and 4: A4175 Keynsham Road - at the bridge over the River Avon  Sites 5 and 6: B3116 Bath Road - just west of Broadmead Roundabout  Sites 7 and 8: B3116 Wellsway - south of Courtenay Road; and  Sites 9 and 10: Charlton Road - south of new roundabout to Bilbie Green. Figure 2.4 below shows the location of the five ANPR/MCC sites: 11

Figure 2-4: Keynsham ANPR survey locations

The surveys captured all vehicle movements into/out of Keynsham between 0400 and 2200 (18-hour period). Note that ‘through’ traffic using the A4 along the Bypass was not captured by the surveys. This was intended, in that the aim of the surveys was to capture light and heavy vehicle ‘through’ routing affecting the Town Centre. This is of direct interest to the JTS link road proposal, which would seek to remove the ‘through’ traffic component between the A4 Bath Road and A4175 (North) in both directions. Table 2.1 shows the total volume of two-way traffic at each location (18 hour) and the number of HGVs (ABS/%)

Sites Location 18-hour two- HGVs % way flow 0400- HGVs 2200)

1 &2 A4175 Bristol Road – just east of Durley Hill mini-roundabout 17373 1009 6% junction

3 & 4 A4175 Keynsham Road – at the bridge over the River Avon 19009 554 3%

5 & 6 B3116 Bath Road – just west of Broadmead Roundabout 18486 870 5%

7&8 B3116 Wellsway – south of Courtenay Road 11221 475 4%

Sites Location 18-hour two- HGVs % way flow 0400- HGVs 2200)

9&10 Charlton Road – south of new roundabout to Bilbie Green. 9789 367 4%

Total 75878 3275 - Table 2.1: 18-hour flow data 0400-2200 (MCC Figures)

Table 2.2 shows the light vehicle traffic ‘through’ flows over the same period:

A4175 A4175 B3116 B3116 Charlton Bristol Keynsha Bath LV Wellsway Road – Road - m Road – Road – – OUT OUT OUT OUT OUT

Location 2 4 6 8 10 Total

A4175 Bristol Road –IN 1 1476 309 159 135 177 2256

A4175 Keynsham Road – IN 3 305 2352 1324 1149 1008 6138

B3116 Bath Road – IN 5 147 1044 1465 1679 400 4735

B3116 Wellsway – IN 7 169 1116 1599 842 125 3851

Charlton Road – IN 9 189 985 421 115 979 2689

Total 2286 5806 4968 3920 2689 19669

Table 3.2: Matched LV Movements 0400-2200 Table 2.2: Matched LV Movements 0400-2200

The data shows that light vehicle ‘through’ trips or those only making a ‘short’ stop within Keynsham equate to only 19,669 IN movements of 75,878 two-way trips at the ‘cordon’ (so about 38,000 in one-direction with negligible imbalance in the IN/OUT flows over the 18-hour period). This suggests that around 40% of all light vehicle trips have an origin or destination outside Keynsham, with a high proportion of these likely to be outward commuting trips. This is consistent with 2011 Census ‘Journey to Work’ data showing that car remains the predominant mode of travel to work for residents within the Keynsham Wards, and that most work destinations lie outside of the town. Of critical interest to the link road assessment are the identified LV ‘through’ movements between the B3116 Bath Road and the A4175 Keynsham Road, which was some 2,670 two-way trips over the 18-hour weekday period, or around 12% of all ‘through’ traffic. There is thus significant potential for the link road to remove a significant volume of traffic from current routes via the Town Centre, whilst there is potential to attract other ‘through’ trips to/from the Wellsway as well as other local traffic in East Keynsham. 2.3 Existing Transport Problems Keynsham is prone to weekday peak hour congestion problems both within the town, and along the A4. The key points of congestion are as follows:  A4/A4174 Hicks Gate Roundabout: The partially signalled roundabout suffers from congestion on the A4 Bypass, A4174 Ring Road and A4175 Durley Hill approaches in the weekday AM peak period. Much of this is due to ‘exit blocking’ caused by excess queuing on the westbound A4 Bath Road approach to the junction with Emery Road in Brislington. It is noted that the JTS proposals include proposed improvement to this junction in conjunction with a A4-A37 Link Road and a relocated Brislington Park and Ride site. It should be noted, however, that the highway modelling undertaken to consider the operational benefits of the A4-A4175 Link Road

in this OAR does not take account of any proposed infrastructure changes here as part of the wider JTS package;  A4 Bath Road - Eastbound: The eastbound section of the A4 Bath Road between Saltford and Broadmead Roundabout on the outskirts of Keynsham can experience regular occurrence of slowing moving/queuing traffic in the weekday AM peak period in particular. This is partly due to the frequent operation of the two controlled crossings in the centre of Saltford, but stopping buses just east of the Norman Road junction and drivers ‘forcing’ a right turn out of this junction can all contribute to impedance to the high flow of ‘peak’ eastbound traffic on this part of the A4. The ‘shock-wave’ queuing/slow moving conditions created can, on occasion, lead to eastbound queuing on the Bypass approaching Broadmead Roundabout;  B3116 Bath Road/Bath Hill: Operating conditions at the Chandag Road and B3116 Wellsway junctions, both of which are mini-roundabouts, can result in slow moving, queuing traffic in both peak periods. In the AM peak hour, the zebra crossing just west of the Chandag Road mini- roundabout is frequently used by school children walking to Wellsway School. This factor and the operation of the mini-roundabout itself can lead to westbound queuing on the B3116 Bath Road beyond Broadmead Roundabout. Impedance caused by waiting right-turners at this mini- roundabout can also result in queuing affecting the upstream B3116 Wellsway mini-roundabout. Queuing/slow moving traffic on the Bath Hill approach to the B3116 Wellsway mini-roundabout can extend to affect the left turn from Avon Mill Lane, leading in turn to southbound queuing on this route in the AM peak hour;  A4175 Keynsham Road: Regular slow-moving conditions exist on the approach to the Avon Mill Lane junction in the AM peak hour in particular, whilst traffic on Avon Mill Lane attempting to access the A4175 results in queuing which can often extend beyond the ‘pinch-point’ under the low railway bridge; and  Following the introduction of the ‘Town Centre Re-development’ scheme at the southern end of the High Street, there were initial problems with increased queuing on the Bath Hill approach to the ‘reduced’ mini-roundabout junction with High Street/Temple Street. The Council has recently introduced an experimental one-way southbound scheme in the section of the High Street between Charlton Road and Bath Hill. Northbound traffic which formerly used this part of the High Street must now route via Temple Street, Rock Road and Ashton Way. Whilst this scheme is still being monitored with a view to making it permanent, observations suggest that capacity constraint imposed by the two closely situated signal controlled crossing in Temple Street and Rock Road can still result in ‘excess’ queuing affecting Bath Hill on occasion. The overall picture is thus one of regular localised congestion ‘hot-spots’ within Keynsham in the weekday peak hours, in addition to problem locations on the main A4 arterial route. The issues around Hicks Gate are primarily due to ‘exit blocking’ congestion problems on the westbound Bath Road approach to Brislington. On the east side of the town, the variable conditions in the eastbound direction towards Saltford (AM) is generally caused by link flows close-to or exceeding the achievable link capacity, which is itself governed by a number of key factors generating impedance. Whilst the delivery of a A4 Bath Road-A4175 link road cannot be expected to address all these operating problems, it is likely to relieve flows on the B3116 Bath Road, Bath Hill and Avon Mill Lane. Specific outcomes are described later in this OAR when discussing the traffic modelling outputs associated with different alignment and layout options taken forward from initial ‘sifting’ 2.3.1 Wider connectivity challenges in Keynsham There are currently only two crossings of the railway between the main part of Keynsham (including the Town centre) and the area to the north, including the large area of new development at Somerdale. These two crossings are the A4175 Keynsham Road (passing over the railway between the Town centre and the station) and Avon Mill Lane (a very low headroom bridge under the railway to the east).

In order to travel between the A4 from the east and A4175 to the north, drivers must use the B3116 Bath Road, Bath Hill and Avon Mill Lane, or route through the Town Centre via Ashton Way, the High Street and Station Road. The bridge under the railway at Avon Mill Lane has a very low headroom: this means that lorries are required to travel through Keynsham town centre (via High Street and Station Road) to cross the railway to the A4175. This means that high volumes of traffic, particularly goods vehicles, are effectively forced through Keynsham town centre due to the lack of viable alternatives for crossing the railway. This creates problems of congestion, pollution and severance, and constrains opportunities to improve public transport and public realm through the town centre.

3 Understanding the Future Transport Situation 3.1 Future Land Uses and Policies 3.1.1 Committed developments The Local Plan for BANES (2011-2029) comprises two separate Development Plan Documents: the Core Strategy (adopted July 2014) and the Placemaking Plan (adopted July 2017). Volume 3 of the adopted Placemaking Plan focuses on Keynsham. BANES Council is currently preparing a new Local Plan for the District. The new Local Plan 2016-2036 Issues and Options document was published for comment in November 2017. The document will undergo further rounds of consultation before formal adoption. The adopted Core Strategy for BANES outlines a requirement for 12,956 houses which includes both the local plan delivery shortfall (1996-2011) and demographic need (2011-2029). 2,150 of these houses are to be provided in Keynsham, of which 1,600 will be provided through Strategic Sites. 1,600 new jobs will also be created between 2011 and 2029 primarily by increasing the stock of office floorspace in Keynsham, complemented by an extension to the Broadmead/ Ashmead/Pixash industrial Estate. Strategic Sites in Keynsham are located to the south west and east of the town (Figure 3.1 and also the constraints plan in Appendix A), and the Core Strategy states that “land is removed from the Green Belt to the south west and east of the town and allocated for development in order to provide additional employment floor space and housing”. Within the Core Strategy, land has also been removed from the Green Belt at East Keynsham and safeguarded for possible development in the future. Development of this land will be permitted only when allocated for development following a review of the plan.

Figure 3-1: Keynsham Spatial Strategy (Core Strategy 2011-2029) In submitting evidence for the EiP into the DRAFT Place Making Plan (PMP) In September 2016, the committed and agreed land use development assumed in the forecast year S-Paramics model testing for Keynsham included the following:  Somerdale (Policy KE2A): 700 dwellings and 10,000 square metres of B1;  Riverside and Fire Station Site (Policy KE2B): Mixed use retail/residential;  Land Adjoining East Keynsham (Policy KE3A): 250 dwellings;  Land Adjoining East Keynsham (Policy KE3A): Business Uses (B1/B2/B8);  Safeguarded Land at East Keynsham (Policy KE3B): EXCLUDED;  Land Adjoining South West Keynsham (Policy KE34): 200 dwellings;  Bilbie Green (Site K2A): 266 dwellings (planning permission granted February 2015 (12/00049/FUL); and  The Meadows (Site K2B): 285 dwellings (planning permission granted July 2011 (09/04351/FUL). This level of ‘committed’ development at an assumed forecast year of 2029 has been used in the operational testing of the options taken forward from initial sifting, with overall growth from the 2011 ‘base model’ capped to the latest predicted 2011-2029 growth for Keynsham in TemPRO (as required by WebTAG). 3.1.2 JSP proposals In order to deliver the housing requirement for the West of England of 102,200 homes between 2016 and 2036, the JSP makes provision for the supply of at least 105,500 new homes, to enable flexibility. 14,500 of these dwellings are to be provided in Bath and North East Somerset. The Spatial Strategy also supports the delivery of 82,500 jobs across the West of England.

In order to achieve the JSP housing and job requirements, Strategic Development Locations have been identified across the region (Figure 3.2). Two are located within BANES as follows:  North Keynsham; and  Whitchurch.

Figure 3-2: JSP Key Diagram, showing SDL locations 3.1.2.1 North Keynsham SDL This SDL lies to the North East of Keynsham, between the town and the River Avon. The majority of the area lies between the river and the Great Western Main Line (GWML) with a smaller section between the railway and the A4. It also includes the land south of the A4 which is safeguarded for development through BANES Core Strategy (Policy KE3A). Development at the North Keynsham SDL is expected to include:  The delivery of around 1,500 new homes, with 1,400 homes built in the plan period, optimising densities and including affordable housing.  Around 50,000 m2 of employment floorspace.  Creation of a new local centre to provide a focal point for the new community with an appropriate range of small-scale retail, services and facilities.  A new primary school on site and financial contribution to the provision of a secondary education provision off site.  New mixed tenure marina providing residential and leisure moorings.  Provision of key transport infrastructure including: – North Keynsham multi modal link from Avon Mill Lane to A4. This new link will be designed as a street through the development, considering the needs of pedestrians, cyclists, public

transport and vehicles, and capable of performing a wider strategic function for traffic relief in Keynsham. Development will have a positive relationship with the link road; – pedestrian and cycle connections in all directions which link the site with key services and facilities. These include Keynsham rail station, the town centre, the A4 public transport corridor, the A4175 Keynsham Road and the Bristol to Bath cycle path with the potential for new bridge connections across the River Avon; – where existing vehicle routes across the railway line are no longer required for continued use by motor traffic, seek to downgrade them to pedestrian and cycle only links; – Metrobus (high quality public transport) route from Bristol to Keynsham on the A4 corridor; – high frequency local bus service following an orbital route connecting the site to the town centre, Metrobus, rail and other local bus services; – improved passenger facilities at Keynsham rail station; – off-site junction improvements including at Hicks Gate; and – expanded or relocated A4 Bristol Park & Ride. As the SDL site is constrained by both the railway line and river, new access is required in order for the site to be developable. The JSP states that: “No housing will be completed at the North Keynsham SDL ahead of the Avon Mill Lane to A4 link, Keynsham rail station improvements and Metrobus (high quality public transport) route from Bristol to Keynsham on the A4 corridor being completed. This should not prejudice a full Transportation Assessment which will be required for each location.” 3.1.2.2 Whitchurch SDL The development of land at Whitchurch SDL will include:  Around 2,500 new homes, optimising densities with 1,600 homes built in the plan period, including affordable housing.  Employment, retail, education, provision of key transport infrastructure No dwellings will be completed at the Whitchurch SDL ahead of:  Park & Ride; and  the multi-modal link A4-A37-south Bristol link including as a pre-requisite, the Callington Road scheme being completed. 3.2 Future Changes to the Transport System 3.2.1 Keynsham Transport Strategy A new Keynsham Transport Strategy was approved in July 2016. The strategy looks to reduce the existing problems caused by congestion and support delivery of the Core Strategy, enabling growth. It also builds on the policies and measures included in successive Joint Local Transport Plans. The strategy includes the following measures as high priorities in the short term to meet the vision and objectives:  Improved cycle routes to the main schools.  Improved pedestrian facilities in the town centre and to/from the centre and rail station.  Continue to work with the bus operators on improved ticketing and simplified fare structure. The Council is to actively progress and monitor their Corporate Travel Plan at the Civic Centre.  An improvement at the Wellsway, Bath Hill and Bath Road junction to increase its capacity.

Figure 3-3: Potential transport infrastructure improvements (source: Volume 3 of the Place Making Plan for BANES)

Figure 3-4: Current and proposed bus, pedestrian and cycle routes (source: Volume 3 of the Place Making Plan for BANES)

3.2.2 West of England Joint Transport Study To aid ‘joint working’ The West of England Combined Authority (WECA) was established in May 2017 with the election of the new Metro Mayor. Comprising BANES, Bristol and South Gloucestershire, it is working with partners including the West of England Local Enterprise Partnership, North Somerset Council and other local service providers. Critically, this new Mayoral body provides devolution of transport budgets, enabling the sub-region to potentially deliver more ambitious transport projects with greater certainty. In addition to accommodating committed growth, the JSP recognises that the transport network will need to cater for the increased demand for travel resulting from employment and population growth in the wider catchment area. As such, the JSP is complemented by the Joint Transport Study (JTS), which sets out the transport vision required to deliver the spatial strategy in a sustainable manner. The JTS was endorsed by the West of England Joint Committee on 30th October 2017. Building on the current West of England Joint Local Transport Plan (LTP) 2011-2026, it has been undertaken in parallel to develop strategic transport proposals for delivery up to 2036 that address current challenges on the network and to inform future development proposals. The South East (Bath to Bristol) section of the JTS includes Keynsham, and priorities for this are to include:  Improved orbital connectivity in South Bristol;  Improved connectivity in the Bristol-Bath corridor;  Reduced impacts to through traffic in Bath; and  Improved regional connectivity to the south coast. The proposals are shown on Figure 3.5.

Figure 3-5: South East Area (Bath to Bristol)

The JTS includes a vision for the following local complimentary schemes:

Figure 3-6: Complementary JTS proposed schemes

With regard to the A4 corridor via Keynsham and Saltford, the JTS includes a proposal for “mass transit between Bristol and Bath… to complement an improved rail corridor and better accommodate a wider range of trip patterns”. In addition, the focus of this study, a new highway connection from the A4 to the A4175 at Avon Mill Lane is included. The JTS states that “this will provide access to the North Keynsham Strategic Development Location and will also provide traffic relief in Keynsham town centre”. Appendix A of the JTS sets out the detailed assessment of the 34 major schemes included in the Transport Vision, including the A4 to Avon Mill Lane Link, Keynsham. Appendix A states that: “Significant growth is planned at Keynsham in the existing Bath & North East Somerset Core Strategy. The Placemaking Plan for Keynsham includes provision for a new highway link between the A4 and A4175 via Avon Mill Lane, to ease congestion in the town and to provide access to development. The JSP also proposes strategic development at North Keynsham, which would require access via this route.” 3.3 Future Traffic Demand As noted in Sub-Section 3.1.1, the traffic generation impact of the non-JSP ‘committed’ development growth was previously quantified in undertaking work for the PMP EiP in September 2016, and in earlier work examining land use development options for the Core Strategy. The highway modelling tool used then, as in the OAR work reported now, is the detailed S-Paramics micro-simulation model of Keynsham. This has a calibration/validation ‘base year’ of 2011, with the model being developed in the first instance to examine the impact of the Somerdale development. The S-Paramics model covers the weekday periods 7:00-10:00 am and 3:00-7:00 pm. Whilst its extent does not allow for consideration of wider potential re-routing impacts associated with new infrastructure provision or development proposals in Keynsham, it does facilitate and allow for detailed ‘real time’ modelling of the key parts of Keynsham which would be affected by the delivery of a new link road connecting the A4175 (North) with the A4 Bath Road. The 2011 model matrices for the 7:00-10:00 am and 3:00-7:00 pm periods includes total calibrated demands of 22,447 and 34,488 vehicle trips respectively. TRICS analyses of the various ‘committed’ developments outlined earlier resulted in predicted demands of 24,392 vehicle trips in the AM 22

period and 37,571 vehicle trips in the PM period. This equates to development growth changes of +8.66% and +8.94% respectively. The latest version of TemPRO was then examined to ascertain predicted car driver trip growth over the period 2011-2029 within Keynsham. The mean growth forecasts obtained for the AM and PM periods were +7.40% and +7.24%. In view of this there was no requirement to apply additional background growth to that expected by the ‘committed’ developments. Instead, and in line with WebTAG guidance, the overall growth was ‘capped’ to the TemPRO forecast for each period by applying a global reduction factor to each 2029 demand matrix. It should be noted and emphasised that the future ‘vehicle’ demand used in the S-Paramics models for testing ‘short listed’ link road options does not allow for the development impact of the JSP proposed SDL at North Keynsham, or indeed the potential impact of the SDL at Whitchurch. This is in line with WebTAG, which advises that bespoke consideration of development in future year forecasting should only include those which are ‘committed’ or ‘reasonably certain’. The wording in TAG Unit M4 ‘Forecasting and Uncertainty’ states in paragraph 3.2.4 that “Local sources of uncertainty categorised as near certain should be included in the core scenario, whilst all sources categorised as hypothetical should be excluded. Between these two categories, an element of judgement may be required, but usually it would be expected that those inputs categorised as more than likely will be included in the core scenario, whilst those categorised as reasonably foreseeable will be excluded”. The SDLs could at best be described as only ‘reasonably foreseeable’. The situation is somewhat complicated in the case of the North Keynsham SDL, as clearly a link road delivering improved access across the GWML would be a prerequisite to delivery of development here. This brings it into the category of ‘dependent’ development, about which TAG unit A2.3 ‘Transport Appraisal in the Context of Dependent Development’ provides guidance. This identifies a four-step process as follows:  Step 1: Determine whether new housing is dependent on a transport scheme;  Step 2: Identify an appropriate transport scheme;  Step 3: Assess the benefits of the transport scheme in isolation; and  Step 4: Assess the benefits of the dependent development. In the case of the North Keynsham SDL the ‘Step 1’ outcome is clearly yes, whilst the purpose of this OAR is to consider link road options providing improved access to the north side of the GWML to deliver the key objective of adequately servicing the SDL land (Step 2). Assessing the schemes under a ‘core’ scenario with ‘committed’ development only fulfils the requirements of Step 3. With respect to Step 4 the recommended method is to “estimate the 'planning gain' arising from the dependent new homes; then subtract the net external costs caused by the dependent new homes”. The latter external costs include the additional ‘transport costs’, in other words the degree to which operating benefits arising from the scheme in isolation could be expected to reduce with the development. In the case of the North Keynsham SDL this creates the following potential issues:  Satisfactory delivery of both this SDL and the Whitchurch SDL is likely to be dependent on the whole ‘package’ of JTS infrastructure improvements around Keynsham, not just this link road. So, the delivery of improvements to Hick Gate roundabout, the construction of a A4-A37 road link and planned public transport enhancements along the A4 corridor; so  It would not be appropriate to assess ‘dependency’ of the North Keynsham SDL against the sole delivery of a A4-A4175 link road option as a ‘sensitivity’ test. However, to meet the requirements of TAG A2.5, a separate exercise has been undertaken in other work using the strategic GBATS model, which considers all the SDL locations and the entire JTS infrastructure ‘package’ of transport proposals. This is reported separately and ‘Step 4’ analyses form no part of the model testing with S-Paramics in this OAR.

3.4 Future Transport Related Problems 3.4.1 Base-line Modelling (2029) The majority of the North Keynsham Strategic Development Location (SDL) is north of the Great Western Main Line. A new transport link will be required to provide access to the SDL, together with improved public transport provision including a MetroBus link to Bristol and enhanced Park & Ride facilities on the A4 corridor. The provision of new or improved crossings over the railway will be critical to ensuring adequate connectivity to support new development. The scheme would also help facilitate improved connections around the north of the town, connecting the A4 Bath Road near the Broadmead roundabout to the A4175. Revised Reference Case modelling done for the purposes of this OAR reinforces past base-line work undertaken to support the PMP EiP. This base-line assessment work has shown that the Keynsham network with recent and identified highway works implemented is capable of accommodating future ‘committed’ growth during the weekday morning peak period (7:00-10:00 am), albeit with a high degree of delay. However, during the afternoon/evening period from 3:00-7:00 pm, the assessment suggests that the network would struggle to cope with the predicted demand during the 5:00-6:00 pm peak hour, unless a significant improvement scheme to the A4/A4174 Hicks Gate Roundabout is implemented. Even so, a significant degree of congestion would remain, although the network results suggest that the network would just cope in accommodating the passage of nearly all the forecast traffic. Delivery of an improvement scheme for the A4/A4174 Hicks Gate Roundabout is a proposed JTS intervention linked with the delivery of a A4-A37 link road. In the earlier evidence work presented to the PMP EiP it was further stated that “Consideration of other further highway improvements, such as a possible Avon Mill Lane-A4 Bath Road Link Road, are clearly desirable to maintain the reliability and resilience of the Keynsham highway network in the face of significant development growth within the town. This is because a future network operating close to or at capacity could be subject to considerable variability in journey time reliability in the ‘peak’ periods, as the S-Paramics model runs have demonstrated. This is recognised in the PMP, where policy provision is made for further investigation of strategic improvements”. Further consideration of the best options for this link are clearly set out in this OAR. 3.4.2 Connectivity from the North Keynsham SDL The SDL is located in the Broadmead area between the A4 Bath Road and the River Avon, with the majority of the site to the north of the railway near to the Avon Valley Wildlife Park. Access to this area from the rest of Keynsham is currently poor, with similar challenges of severance caused by the railway. Access is potentially available from the A4175 to the north of the railway, via Avon Mill Lane, but this would require acquisition of third party land and the provision of an east-west access road to connect from Avon Mill Lane to the Broadmead area. The SDL will also require access to the A4 Bath Road to connect with Keynsham and the wider transport networks, but these connections are currently highly constrained. Neither of the existing railway crossings at Broadmead Lane and Pixash Lane provide satisfactory walking and cycling connections to Keynsham, whilst they are unsuitable for accommodating the traffic that would be generated by the SDL. The Broadmead bridge is narrow with no footways and has a low headroom under the railway. Pixash Lane is a narrow bridge over the railway (and is Grade II listed), with narrow and steep approaches from each side. There is a third crossing at Unity Road that connects to a small Industrial Estate to the north of the railway with similar characteristics to the Broadmead Lane crossing, but this does not directly link to the A4 bath Road; rather it connects back to Broadmead Lane.

3.4.3 Requirement for improved connectivity from Broadmead to A4 It will therefore be necessary to improve access to the A4 Bath Road from the Broadmead area, with at least one new or improved crossing of the railway. This will then connect, via a new east-west link on the north side of the railway to the A4175. This will be required to provide effective connectivity from the SDL and will also provide an alternative traffic route between the east and north of Keynsham, providing wider connectivity and resilience benefits for the town. Options for crossing the railway include creating a wider structure under the railway at Broadmead Lane, a new wider structure immediately to the east of Pixash Lane, or a completely new bridge over the railway on a new road alignment to the east of Pixash Lane. Failure to provide adequate infrastructure to address the challenges described above will pose a delivery risk to development at this location. The function of the new transport infrastructure in this area will be to:  Provide access to the Keynsham SDL;  Reduce traffic flows and relieve traffic pressures on routes through Keynsham; and  Deliver improved facilities for pedestrians, cycling provision and effective public transport services. These are key factors that need to be considered in the assessment of potential options for the corridor.

4 Need for Intervention, Objectives and Geographical Scope 4.1 Summary of Current and Future Problems, Impacts and Outcomes In summary, intervention is needed due to:  The limited number of crossings of the railway line between north Keynsham (A4175) and the rest of the town. Traffic is therefore concentrated through a limited number of crossings, many of which have limited headroom.  This results in heavy traffic flows, including goods vehicles, through Keynsham town centre, causing congestion and poor air quality.  New committed housing development and economic growth in Keynsham will exacerbate these problems.  Poor access to the Broadmead area, via substandard bridges, constraining potential for development in this area.  Proposals for a Strategic Development in North Keynsham, requiring access across the railway (car, cycle, and walking). 4.2 Scheme Objectives and Outcomes The JTS sets out the following objectives for the A4 to Avon Mill Lane Link, Keynsham (Road 13). Previous work assumes the Avon Mill Lane connection is ‘fixed’ in providing through access to the A4175. In our view, this cannot be taken as a given in seeking to deliver SDL growth above that already ‘committed’ in Keynsham:  Provide effective access to the new development area in North Keynsham (SDL).  Reduce traffic flows and relieve traffic pressures on routes through Keynsham.  Deliver improved facilities for pedestrians, cyclists and effective public transport in North Keynsham These objectives have been reviewed and tailored into general and corridor/site specific objectives: General Objectives  Improve transport network resilience and journey time reliability. Specific Objectives  Provide effective access to the new development area in North Keynsham (SDL).  Reduce traffic flows and relieve traffic pressures on routes through Keynsham.  Deliver improved facilities for pedestrians, cyclists and effective public transport in North Keynsham.  Not prejudice the improvement and retention of traffic reduction measures in the Town Centre (an experimental one-way southbound scheme is presently in place on the High Street between Charlton Road and Temple Street). 4.3 Measures for Success The table below presents measures for success for each objective. Objective What do we need to do to achieve this How will we measure our success

Objective What do we need to do to achieve this How will we measure our success Improve transport network  Provide suitable capacity junctions. Results of traffic resilience and journey time  Provide a convenient connection as an alternative modelling – flows reliability. to the Bath Road and Bypass. and delay  Provide a choice of routes thus disbursing Traffic volume and congestion effects. speed data Provide effective access to the  Provide suitable capacity junctions. Monitoring of new development area in  Location of link appropriate to serve SDL. development access North Keynsham (SDL). Reduce traffic flows and  Provide a convenient connection as an alternative Results of traffic relieve traffic pressures on to the Bath Road. modelling – flows routes through Keynsham.  Provide a choice of routes thus disbursing through Keynsham congestion effects. Traffic volume and speed data Deliver improved facilities for  Protect public transport routes, including proposed Consideration during pedestrians, cyclists and MetroBus routes. design process effective public transport in  Provide improved quality cycle routes and Details of changes to North Keynsham. connections. the built  Provide improved pedestrian opportunities. environment Mode share data Enable the improvement and  Provide a choice of routes thus disbursing Results of traffic retention of traffic reduction congestion effects, particularly in the Town Centre. modelling – flows measures in the Town Centre. through Keynsham

Town Centre traffic surveys Table 4.1: Measures for Success

5 Generating and Initial Sifting of Options 5.1 Approach to Option Generation The JTS has identified the need for a new highway link from the A4, crossing the railway to connect to Avon Mill Lane and A4175 north of Keynsham. The scope of this study is therefore to consider potential highway alignments for a new link road connecting the A4 Bath Road with the A4175 Keynsham Road on the north side of Keynsham. Options have been proposed based on previous studies, including the 2017 Atkins paper which set out three options for the provision of a new highway link. In addition to these options, a number of other options have been developed based on:  General and corridor/site specific objectives;  Local capacity on the highway network;  Land use planning aspects;  High level environmental constraints; and  Fit with existing local, regional and national programmes and strategies. 5.2 Results of Option Generation In generating a ‘long list’ of potential options the assessment work in this OAR has drawn on previous studies, which include the following:  A detailed feasibility report prepared by Tony Gee and Partners in 2004 which considered potential construction options for widening of the Broadmead Lane underbridge to create a 7.3m wide carriageway plus footway / cycleway provision, and standard headroom of 5.3m. It identified that the preferred option would be to use the existing arch bridge opening to construct one abutment and thrust bore the other abutment to provide an off-line two-lane carriageway with footways on both sides. This was not associated with the potential creation of a link road, but rather to look at improving access associated with a former proposal to install a new waste terminal on a 4-5-hectare site owned by B&NES to the north of the railway next to Broadmead Lane;  Option alignments (Options 1 and 2) developed by CH2M in 2013, showing possible alternative link road routes via Broadmead Lane and Pixash Lane. The Pixash Lane option (Option 2) proposed a new over-bridge structure just east of the existing Grade 2 listed bridge, with the latter retained for pedestrians and cyclists. The Broadmead Lane option (Option 1) proposed removal of the existing brick low arch bridge and replacement with a structure with a 5.3m minimum headroom. Both options assumed connection to Avon Mill Lane via a linkage north of the sewage treatment works and through the DH Smith (former papermill) land;  Transport modelling undertaken by CH2M in 2015 using S-PARAMICS to assess the impacts of the routes via Broadmead Lane and Pixash Lane (Options 1 and 2 above) on the performance of the transport network. The analyses demonstrated that the route via Broadmead Lane would be slightly more beneficial in improving overall network performance, because this would offer a more direct route around the north of Keynsham and there would be slightly less delay for traffic using the Broadmead Roundabout than a signalised A4/Pixash Lane junction. The results, not unexpectedly, showed that the highest degree of traffic relief would be to the B3116 Bath Road, Bath Hill and the section of Avon Mill Lane between the railway bridge and Bath Hill. This work also highlighted the criticality of the A4175/Avon Mill Lane junction as a potential bottleneck constraint to the attractiveness of either link road route without works to improve capacity; and

 Options 1, 2 and 3: Strategic Planning Framework 2017 study produced by Atkins in May 2017, setting out the key constraints at the North Keynsham site, including consideration of access via Avon Mill Lane, Broadmead Lane and Pixash Lane. Subsequent to the above, in the supplied Atkins Background Paper TN ‘East of Keynsham: Review of rail crossing options for road links north of Keynsham (Avon Mill Lane) (Revised Draft)’, dated 6th July 2017 only three alignment options were presented for this link. This and the JTS (Appendix A) considered three different options for achieving improved access over the Great Western Main Line (GWML) from the A4 Bath Road at the eastern end of the link, but assumes a fixed connection to the A4175 Keynsham Road via Avon Mill Lane at the western end. This critically assumes that an improved form of the A4175/Avon Mill Lane junction will be deliverable to service not only ‘committed’ development identified in the B&NES Core Strategy and Place Making Plan to 2029, but also the Strategic Development Location (SDL) identified north of Keynsham for housing (up to 1,500 dwellings). At present, there is a s106 requirement on the Somerdale development to deliver a traffic signal improvement scheme for this junction. Previous modelling work (S-Paramics) undertaken for both the Somerdale Transport Assessment, the Core Strategy and the PMP EiP has shown that this improvement will cater for ‘committed’ development growth to 2029. However, what is currently planned here in terms of improvement will not provide for SDL growth. In view of this the options work has been extended to consider possible alternative connection points with the A4175, as well as the potential for ‘step-change’ capacity improvements to the A4175/Avon Mill Lane junction. As noted above, without the latter, the link road would fail in one of its primary objectives in facilitating the SDL. All the alignments considered are shown in Figure 5.1 (and in further detail in Appendix B) and are described in Table 5.1.

Figure 5-1: Scheme Options

Option Ref Description

1A Uses Broadmead Lane with a widened opening under the GWML embankment to facilitate two-way traffic and footway provision. Connection to Avon Mill Lane via a linkage adjacent to the north side of the sewage treatment works and through the former paper mill site. A significant up-grade of the A4175/Avon Mill Lane junction would be necessary as part of this scheme. 1B Uses Broadmead Lane with a widened opening under the GWML embankment to facilitate two-way traffic and footway provision. Alternative connection to the A4175 (not via Avon Mill Lane) just north of Keynsham Marina requiring a new bridge structure over the River Avon. 1C Uses Broadmead Lane with a widened opening under the GWML embankment to facilitate two-way traffic and footway provision. Alternative connection to the A4175 (not via Avon Mill Lane) with a river crossing and new junction further north, avoiding a direct impact of existing properties just north of the Marina (1B.). 2A Uses Pixash Lane with a new over-bridge to the GWML just east of the existing Grade 2 listed structure. The latter would be retained as a dedicated pedestrian/cyclist link and closed to traffic. Connection to Avon Mill Lane via a linkage adjacent to the north side of the sewage treatment works and through the former paper mill site. A significant upgrade of the A4175/Avon Mill Lane junction would be necessary as part of this scheme. 2B Uses Pixash Lane with a new over-bridge to the GWML just east of the existing Grade 2 listed structure. The latter would be retained as a dedicated pedestrian/cyclist link and closed to traffic. Alternative connection to the A4175 (not via Avon Mill Lane) just north of Keynsham Marina requiring a new bridge structure over the River Avon. 2C Uses Pixash Lane with a new over-bridge to the GWML just east of the existing Grade 2 listed structure. The latter would be retained as a dedicated pedestrian/cyclist link and closed to traffic. Alternative connection to the A4175 (not via Avon Mill Lane) with a river crossing and new junction further north, avoiding a direct impact of existing properties just north of the Marina (2B). 3A New link road connection between the A4 Bath Road and the GWML through land to the east of the Ashmead Industrial Estate. This forms part of the SDL. A new over-bridge to the GWML would be required and a link to Broadmead Lane. The existing Pixash Lane bridge would be closed to traffic and used as a dedicated pedestrian/cyclist linkage. Access through the Broadmead Lane under-bridge would be retained as a one-way traffic linkage to the new road (NB). Connection to Avon Mill Lane via a linkage adjacent to the north side of the sewage treatment works and through the former paper mill site. A significant upgrade of the A4175/Avon Mill Lane junction would be necessary as part of this scheme. 3B New link road connection between the A4 Bath Road and the GWML through land to the east of the Ashmead Industrial Estate. This forms part of the SDL. A new over-bridge to the GWML would be required and a link to Broadmead Lane. The existing Pixash Lane bridge would be closed to traffic and used as a dedicated pedestrian/cyclist linkage. Access through the Broadmead Lane under-bridge would be retained as a one-way traffic linkage to the new road (NB). Alternative connection to the A4175 (not via Avon Mill Lane) just north of Keynsham Marina requiring a new bridge structure over the River Avon. 3C New link road connection between the A4 Bath Road and the GWML through land to the east of the Ashmead Industrial Estate. This forms part of the SDL. A new over-bridge to the GWML would be required and a link to Broadmead Lane. The existing Pixash Lane bridge would be closed to traffic and used as a dedicated pedestrian/cyclist linkage. Access through the Broadmead Lane under-bridge would be retained as a one-way traffic linkage to the new road (NB). Alternative connection to the A4175 (not via Avon Mill Lane) with a river crossing and new junction further north, avoiding a direct impact of existing properties just north of the Marina (3B). Table 5.1: Long list of options 5.3 Approach to Initial Option Sifting All scheme options have undergone a robust but proportionate sifting process to identify a short-list of the better performing schemes that justify more detailed development and consideration. The DfT ‘Transport Analysis Guidance: The Transport Appraisal Process’8 outlines the approach to be taken for the initial sifting of options.

8 https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/431185/webtag-tag-transport-appraisal-process.pdf 30

It states that ‘an initial sift should… be undertaken to identify any ‘showstoppers’ which are likely to prevent an option progressing at a subsequent stage in the process’. The process involves discarding options that:  ‘would clearly fail to meet the key objectives identified for intervention;  do not fit with existing local, regional and national programmes and strategies, and do not fit with wider government priorities; and  would be unlikely to pass key viability and acceptability criteria (or represent significant risk) in that they are unlikely to be: - deliverable in a particular economic, environmental, geographical or social context e.g. options which would result in severe adverse environmental impacts which cannot be mitigated against or where the cost of doing so is too high; - technically sound; - financially affordable; and, - acceptable to stakeholders and the public.’ The initial long list of options has therefore been assessed against the defined scheme objectives, and against the five cases reported in a Transport Business Case. These five cases show whether schemes:  are supported by a robust case for change that fits with wider public policy objectives – the ‘strategic case’;  demonstrate value for money – the ‘economic case’;  are commercially viable – the ‘commercial case’;  are financially affordable – the ‘financial case’; and  are achievable – the ‘management case’. In order to assess options against the five cases, the following supporting studies have been undertaken. These are included in the listed appendices:  Geology and Ground Conditions (Appendix C);  Environmental Baseline (Appendix D);  Flooding (Appendix E);  Services (Appendix F); and  Structures (Appendix G). The detailed (desk based) assessment within these studies has assisted with the identification of ‘showstoppers’, as referenced in the Transport Analysis Guidance. In particular, whether scheme options are deliverable or would result in severe adverse environmental impacts. 5.4 Results of Initial Sifting All of the options presented in Table 5.1 have been considered against scheme objectives and the five cases. Option Sifting Tables showing the analyses are included as Appendix H, with decision making/comments based on the constraints and technical work undertake to date (presented in Appendices C to G), The results of the initial sifting are summarised in Table 5.2, with information on any ‘showstoppers’ presented in Table 5.3.

Option Strategic Case Economic Case Management Details

Case

Support Support Objectives to SDL Access Economic Growth Environment Being Well Timescales Deliverability 1A Pass Partial Pass Fail Pass Pass Fail Discard based on deliverability. Structural assessment of the underbridge works necessary indicates that a lowering of the existing carriageway level will be needed (0.9m). This could have significant drainage and services implications on the south side, which is locally affected by flooding events now (Flood Zone 3). The Broadmead Lane route also provides the least effective ‘direct’ access to the identified SDL land at North Keynsham, which is a ‘key’ objective. 1B Pass Partial Pass Fail Pass Pass Fail Discard based on deliverability and environmental impact. Notwithstanding the deliverability issues with the GWML underbridge widening, initial highway alignment design (vertical) has shown that attaining bridge clearance over the River Avon whilst achieving satisfactory connection in level terms with the A4175 is unlikely to be achievable without a realignment of Keynsham Road westwards. This is in addition to necessary property demolition and impact on land in Flood Zone 3. The Broadmead Lane route also provides the least effective ‘direct’ access to the identified SDL land at North Keynsham, which is a ‘key’ objective. 1C Pass Partial Pass Fail Pass Pass Fail Discard based on deliverability. As 1A. The Broadmead Lane route also provides the least effective ‘direct’ access to the identified SDL land at North Keynsham, which is a ‘key’ objective. Note: As this alignment impacts on land in Flood Zone 3 the Environment Agency are likely to object to any supporting highway structure on the south side of the new river bridge that blocks the ‘flood path’. However, this may be possible to address by appropriate design. 2A Pass Pass Pass Pass Pass Pass Pass Retain 2B Pass Pass Pass Fail Pass Pass Fail Discard based on deliverability and environmental impact. As 1B. 2C Pass Pass Pass Pass Pass Pass Pass Retain 3A Pass Pass Pass Pass Pass Pass Pass Retain 3B Pass Pass Pass Fail Pass Pass Fail Discard based on deliverability and environmental impact. As 1B and 2B. 3C Pass Pass Pass Pass Pass Pass Pass Retain Table 5.2: Long list of schemes considered

The key element dismissed at this stage is an Option 1 linkage via a widened Broadmead Lane under- bridge to Broadmead Roundabout. Both the Structures assessment (Appendix G) and the FRA (Appendix E) highlight the significant delivery issues with this widening. These issues include:  If a widened on-line opening of 12.8m (comprising a 7.3m carriageway, 3.0m wide footway and 3.5m combined footway/cycle path) were to be adopted, the deck depth requirement would increase to 0.85m and the road would have to be lowered by 0.9m below its existing level. Any dip in the road profile would have implications for drainage and vulnerability to flooding, noting that the area immediately south of the portal is already high risk and within Flood Zone 3;  The FRA concern is the lowering of the road under the railway. This would form a low spot in the road that would be potentially lower than the watercourse that any drainage would discharge into. Pumping would thus likely be required to manage surface water flows;  The FRA also advised that Option 1 was most at risk from sewer flooding given there is a private sewer along the road under the railway bridge, as well as highway drains in close proximity to this underpass). As Route Option 1 involves lowering the road, this would lead to increased depths of flooding in a sewer-flooding event; and  The services drawings (Appendix F) also show that there is a significant concentration of utilities apparatus running under this portal or through the Broadmead Lane/Unity Road junction on the south side. This include gas and water mains and British Telecommunications/Virgin Media cables. There are likely to be substantive costs with either diverting or lowering these, and a greater risk of water ingress to vulnerable apparatus due to risk of more frequent surface water inundation. As such, the sifting assessment process has identified four ‘short list’ options for providing a link between the A4 Bath Road with the north of Keynsham which satisfy the defined objectives, and have the greatest potential for deliverability. The shortlisted schemes identified to connect the A4 Bath Road with North Keynsham, are:  Option 2A - Uses Pixash Lane with a new over-bridge to the GWML just east of the existing Grade 2 listed structure. The latter would be retained as a dedicated pedestrian/cyclist link and closed to traffic. Connection to Avon Mill Lane via a linkage adjacent to the north side of the sewage treatment works and through the former paper mill site. A significant upgrade of the A4175/Avon Mill Lane junction would be necessary as part of this scheme;  Option 2C - Uses Pixash Lane with a new over-bridge to the GWML just east of the existing Grade 2 listed structure. The latter would be retained as a dedicated pedestrian/cyclist link and closed to traffic. Alternative connection to the A4175 (not via Avon Mill Lane) with a river crossing and new junction further north, avoiding a direct impact of existing properties just north of the Marina (2B);  Option 3A - New link road connection between the A4 Bath Road and the GWML through land to the east of the Ashmead Industrial Estate. This forms part of the SDL. A new over-bridge to the GWML would be required and a link to Broadmead Lane. The existing Pixash Lane bridge would be closed to traffic and used as a dedicated pedestrian/cyclist linkage. Access through the Broadmead Lane under-bridge would be retained as a one-way traffic linkage to the new road in the northbound direction. Connection to Avon Mill Lane via a linkage adjacent to the north side of the sewage treatment works and through the former paper mill site. A significant up-grade of the A4175/Avon Mill Lane junction would be necessary as part of this scheme.  Option 3C - New link road connection between the A4 Bath Road and the GWML through land to the east of the Ashmead Industrial Estate. This forms part of the SDL. A new over-bridge to the GWML would be required and a link to Broadmead Lane. The existing Pixash Lane bridge would be closed to traffic and used as a dedicated pedestrian/cyclist linkage. Access through the Broadmead Lane under-bridge would be retained as a one-way traffic linkage to the new road in

the northbound direction. Alternative connection to the A4175 (not via Avon Mill Lane) with a river crossing and new junction further north, avoiding a direct impact of existing properties just north of the Marina (3B). The selected scheme options will be developed and assessed further using the DfT Early Assessment and Sifting Tool. The assessment is presented in the following sections.

6 Option Development and Assessment 6.1 Approach to Option Development and Assessment Preliminary highway design has been undertaken for the short-list link options using OS Land-Line base mapping and LIDAR contour information to examine horizontal and vertical alignment issues. This has been done to examine and, where possible, design out potential ‘Departures from Standard’ with respect to the Design Manual for Roads and Bridges (DMRB), whilst identifying the extent of earthworks necessary and thus impact on land for accommodation works. The latter is a key issue with both Options 2 and 3, insofar as identifying the earthworks needed to form the abutments for the bridges over the GMWL, whilst achieving ‘tie-in’ with existing highway accesses on the north side of the railway. It is also a key factor with the Variant C alignment connecting with the A4175 further north, as any elevation of the road here through Flood Zone 3 would need to ensure that the existing flood path is not blocked or unduly impeded. As noted earlier in the ‘long list’ assessments, the form and layout of the terminal junctions with the A4175 and the A4 Bath Road will be critical to determining the overall capacity of this new link road and its attractiveness to drivers, notwithstanding its ability to accommodate planned JSP growth at North Keynsham. In view of this, the design, layout and operation of these terminal junctions has been considered in detail using LinSIG and ARCADY as appropriate, prior to wider area network testing and evaluation with the Keynsham S-Paramics model. The set of preliminary design drawings developed for the short-list schemes are included in Appendix I. The included drawings are as follows:  Drawing No 674726.BP.41.004: Variant A and C connections with the A4175 - General Arrangement;  Drawing No 674726.BP.41.006: Option 2 - General Arrangement;  Drawing No 674726.BP.41.007a: Option 3 - General Arrangement (Sheet 1 pf 2);  Drawing No 674726.BP.41.007b: Option 3 - General Arrangement (Sheet 2 of 2);  Drawing No 674726.BP.41.008: A4175/Avon Mill Lane junction - s106 signal layout (Reference Only);  Drawing No 674726.BP.41.009: A4175/Avon Mill Lane junction - Roundabout Option 1 (as modelled in S-Paramics);  Drawing No 674726.BP.41.010: A4175/Avon Mill Lane junction - Roundabout Option 2;  Drawing No 674726.BP.41.011: A4175 - Proposed Roundabout (Variant C);  Drawing No 674726.BP.41.012: A4 Bath Road - Proposed Pixash Lane Junction Improvements (Option 2) - Layout 1 (as modelled in S-Paramics);  Drawing No 674726.BP.41.013: A4 Bath Road - Proposed Pixash Lane Junction Improvements (Option 2) - Layout 2; and  Drawing No 674726.BP.41.014: A4 Bath Road - Proposed Roundabout (Option 3). The short-list Options (2A, 2C, 3A and 3C) have duly been assessed with respect to the following:  Engineering feasibility;  Cost of construction including ‘Quantitative Risk Assessment’ (QRA) to make a qualified allowance for risk factors;  Deliverability and critically how access for construction to the north side of the railway would need to be accommodated given existing highway access constraints;

 Key environmental impacts, which centre largely on the incursion into land liable to flooding or, in seeking to minimise this, traversal over land formerly used for tipping;  Operational assessment to understand the level of potential traffic usage and relief offered to roads within Keynsham; and  Value for money through estimation of the Benefit Cost Ratio (BCR) for the four short-list options. This uses the overall time saving outputs from S-Paramics to generate a Present Value Benefit (PVB) over 60 years, which is then compared with scheme costs. 6.2 Option Development 6.2.1 Option 2A - ‘Pixash to Avon Mill Lane’ Drawing 674726.BP.41.006 shows the eastern end of the Option 2A scheme, namely the new bridge over the GWML which is located just east of the existing arch bridge (Grade 2 listed) and the use of Pixash Lane as a connection to the A4 Bath Road. A critical factor will be achieving the necessary vertical alignment between Ashmead Road and the height needed for the new bridge over the railway line. Potential issues associated with the construction of this bridge are set out in detail in the structures assessment in Appendix G. Key points are as follows:  Realignment of the road will necessarily use part of the site of the Civic Amenity Site (CAS) to the south of the railway. In order to give a satisfactory vertical alignment for forward sighting distance, the approach ramps will need to be longer and higher than those for the existing bridge; and  For new construction, the soffit height above the railway has to be 5.1m (ref. NR/L3/TRK/2049 figure G.1.1a issue September 2017) to allow for maximum flexibility in the design and installation of overhead line equipment (OLE). The listed status for Pixash Lane Bridge will probably prevent any modification to the bridge in pursuit of increased OLE clearance if any are needed, resulting in track slew or track lowering. Generally listed bridges of this type impose a constraint on the OLE, which has to dip down to a sub-optimal height under the bridge, before rising again on the other side. The bridge construction will therefore affect the CAS entrance. Overall land take within this site will depend on whether an embankment is used on the eastern side of the approach ramp, or a retaining wall. As noted on the drawing, the distance needed to ramp down on the north side of the railway will affect the existing access to Avon Valley Country Park (AVCP), so requiring a new junction position. The existing Grade 2 listed bridge would be retained, and could form a separate pedestrian/cycle link with an informal crossing over the link to AVCP provided on the western side of the roundabout. The latter is needed to facilitate the sharp change in direction needed in the link road, whilst facilitating access connection with the existing lane to Stidham Farm. Drawing No 674726.BP.41.012 shows the proposed changes to the existing major-minor junction between Pixash Lane and the A4 Bath Road. A change in the junction type will be needed to accommodate the higher flows on Pixash Lane resulting from its incorporation in the ‘through’ route, as well as the additional traffic expected with the SDL. A signalled junction is proposed, with the Pixash Lane approach widened to two lanes to ensure sufficient side road capacity can be made available without unduly impacting on the green time available to the A4 Bath Road. This will require some land from the adjacent property. A Departure from Standard would be required in respect of the substandard stop-line inter-visibility in the NW corner of the junction. This could only be overcome by acquiring the property on this corner. Retention of only a single lane approach on the Pixash Lane approach could be considered as shown on Drawing No 674726.BP.41.013, but this would need to be balanced against the likely need for a much longer green time for this side road to the detriment of the A4. In all likelihood, the presence of queuing traffic extending as far as Ashmead Road will encourage drivers turning back into Keynsham to use this estate road as a cut through to Broadmead Lane and so Broadmead Roundabout. However, this may not be considered

desirable. On-street parking which currently occurs on both sides of Pixash Lane would have to be prohibited or severely restricted to ensure the ‘through’ traffic function required under Option 2 is not compromised. The existing vehicular access through the Broadmead Lane under-bridge is to be maintained, albeit in the northbound direction only. This will offer a shorter and more convenient route onto the link for potential car drivers with an origin in East Keynsham requiring access to the A4175 North. Whilst the existing underbridge has two-way traffic permitted, this part of Broadmead Lane is currently very lightly trafficked. The opening of a ‘through’ route would result in a greater risk of conflict and highway safety issues arising through this ‘shuttle working’ section if two-way vehicle movement was retained, with potential for queuing traffic extending onto the small roundabout just north of the portal. The visibility to the left available to drivers on Unity Road at the junction with Broadmead Lane on the south side of the underbridge is also restricted, so increased southbound traffic could make right turn egress hazardous and turning left into the arch particularly so. Drawing No 674726.BP.41.004 shows the ‘Variant A’ connection to Avon Mill Lane which forms part of the Option 2A route. This passes through land formerly used for tipping to the north of the sewage treatment works which is now described as an ‘Open Mosaic Habitat’. Potential issues with cutting into or disturbing what is contaminated ground are set out in the ‘Geology and Ground Conditions’ assessment included in Appendix C. Thereafter the road would pass through the DH Smith site to tie-in to the existing length of private road connecting this land to the mini-roundabout junction with Avon Mill Lane just north of the low railway bridge. A critical aspect of this option is the A4175/Avon Mill lane junction and its future operation. Whilst there is a Section 106 scheme linked to the Somerdale Development to introduce a signal controlled layout (Drawing No 674726.BP.41.008), previous assessment work showed that this would only just accommodate the impact from Somerdale, and may struggle to deliver ‘committed’ growth without further enhancement. In view of this a roundabout replacement option has been developed as shown in Drawing No 674726.BP.41.009. The layout shown has single lane approaches on all arms, the northern of these forming a modified access to the Picnic Site car park which would have to be repositioned in the NE quadrant. On the western A4175 approach from the Town Centre, the wall between the old railway spur (to/from Somerdale) and the roundabout would have to be demolished and repositioned as indicated to achieve the Desirable Minimum Sight Stopping Distance (DMSSD) to the give-way line in compliance with DMRB (70m for a 30mph Design Speed -TD9/93). Drawing No 674726.BP.41.010 shows an alternative layout for a roundabout with two entry lanes on the most heavily trafficked A4175(N) approach. However, modelling described later assumes the former layout with single lane entries. Both layouts include a 3.0m wide shared use footway between the bridge over the River Avon and the Toucan crossing proposed under the Somerdale works by Keynsham Station. This will improve pedestrian access between the Picnic Site car park and the station, whilst it will also extend the existing shared use footway along the A4175 to the north (which terminates at the bridge) to Keynsham Station. The key impacts and risks associated with Option 2A are thus as follows:  Achieving satisfactory operation at the terminal A4 Bath Road/Pixash Lane junction. Domestic land acquisition would be required for improvement, whilst it may be necessary to confine pedestrian facilities here to uncontrolled crossings. This is because upgrading the crossings shown to ‘controlled’ would demand a full pedestrian stage in the Method of Control;  Land impact on the CAS, which is also identified as part of a wider Strategic Employment Site in the Core Strategy/Place Making Plan (Policy KE3A);  Achieving satisfactory vertical alignment between the Ashmead Road junction and the bridge, given potential uncertainty concerning what headroom above track level Network Rail may ultimately seek to require/impose;  Directly affects an existing Site of Nature Conservation Interest just east of Broadmead Lane to the north of the railway (refer to Appendix A - Constraints Plan);

 Necessary encroachment into land formerly used for tipping and with known contamination to the north of the sewage treatment works. This is now designated as ‘Open Mosaic Habitat’ so there could be ecology issues;  Necessary improvements to the A4175/Avon Mill Lane junction to achieve a ‘step change’ increase in capacity over that assessed as achievable with the Somerdale s106 scheme. This will require significant remodelling of the A4175 approach from the Town Centre, and a high risk of substantive services diversion costs. The services drawings (Appendix F) reveal a concentration of gas, water and Virgin Media apparatus on the north side of the existing junction, all of which is likely to need diversion. Traffic modelling and the operational impact of Option 2A is covered in a subsequent sub-section of this chapter. 6.2.2 Option 2C - ‘Pixash to new junction on A4175’ The description of the scheme and design issues between the part of the Option 2C scheme between the A4 Bath Road and Broadmead Lane is the same as Option 2A. As such, it is not repeated here for brevity. The difference is the western connection to the A4175, which in this case is not proposed to be achieved via Avon Mill Lane. Instead, a Variant C connection is proposed with the A4175 at a point further north as shown on Drawing No 674726.BP.41.004. This will require traversal of an extensive area of land within Flood Zone 3 (refer to Appendix A-Constraints and the Flood Risk Assessment in Appendix E). A new bridge over the River Avon would be required to the west of the small industrial estate at the end of Broadmead Lane. To the north of the river, the route would cross agricultural land to the rear of built development along the A4175, with a proposed roundabout junction connection with Keynsham Road (Drawing No 674726.BP.41.011) made between Tudor House and Roseneath. A small roundabout design with single lane approaches is considered adequate, as the right turn from the A4175 (South) and the left turn from the link road are both likely to be low in volume. Consideration could be given to widening the A4175 (North) approach to provide two lanes at entry, although the curtilage of Roseneath will constrain what lane ‘flaring’ at entry can be achieved, whilst the controlling circulating flow across this approach can be expected to be low. As noted above, whilst this option avoids any need to upgrade the A4175/Avon Mill Lane, and other traffic conflicts here, it does not remove the impact on the former tip land now designated as Open Mosaic Habitat. With respect to the impact on flooding in the area, the FRA states in summary for Variant C that: “This option has the greatest impact on fluvial flows - it passes through an area that has experienced recent fluvial flooding. It involves crossing Flood Zone 3 and the river Avon raised above the flood level (assumed to be raised to 14m for this study). Compensatory storage will be required, though this can be reduced if the road is raised on piers rather than an embankment. Detailed modelling will be required to assess the impact of the road (and the river crossing) on fluvial flood flows. If an embankment is proposed, culverts would be required to convey flows under the road. Sizing of these culverts should be informed by fluvial modelling”. On the 9th February 2018, a Preliminary Opinion was received from the EA on a transport scheme in the general study area. The key points from this correspondence were:

“A Flood Risk Assessment would be needed to support any future planning application. This should consider the following specific points:

 Flood risk from all sources  Flood modelling to demonstrate no increase in flood risk elsewhere  Essential infrastructure should remain operational during times of flood  Floodplain compensation (this is an important floodplain) 38

 Any bridges would need to be above the 1% AEP flood level plus climate change. (need to look at a range of allowances)”. It also stated that “under the Environmental Permitting (England and Wales) Regulations 2010, permission from the Environment Agency may be required should any site/site infrastructure works take place in, under, over or within 8 metres of the bank top of the River Avon and Broadmead Brook, designated main rivers”. Furthermore, B&NES supplied a copy of EA comments on the Joint Spatial Plan (dated 10th January 2018 on the 15th February 2018. Key comments on the WECA Joint Spatial Plan related to flood risk management in North Keynsham and were as follows:

 “The Agency would advise that any development will be required to avoid the Keynsham Hams and Broadmead floodplains. Any development within other designated fluvial floodplain will be required to provide floodplain compensation. Any new bridges should be clear span in construction with soffit levels set above the 1 in 100yr climate change flood level”; and  “Any new roads or associated transport improvements would be required to avoid fluvial floodplain and ensure floodplain connectivity”. This indicates that Route Entry Option C ‘The new access to the A4175’ may not be permitted by the Environment Agency. As such, further engagement with the Environment Agency’s Planning team will be required if this option is to be considered further.

It is clear from this that careful design will be needed here. Depending on what the Environment Agency is minded to-require (or accept), this could impact substantively on final out-turn costs whilst there is a potentially high and uncertain level of project risk with this part of the alignment until such time as discussions and formal consultation with the EA have been undertaken. In summary, the key impacts of Option 2C are as follows:  Achieving satisfactory operation at the terminal A4 Bath Road/Pixash Lane junction (As Option 2A);  Land impact on the CAS, which is also identified as part of a wider Strategic Employment Site in the Core Strategy/Place Making Plan (As Option 2A);  Achieving satisfactory vertical alignment between the Ashmead Road junction and the bridge, given potential uncertainty concerning what headroom above track level Network Rail may ultimately seek to require/impose (As Option 2A);  Directly affects an existing Site of Nature Conservation Interest just east of Broadmead Lane to the north of the railway (As Option 2A);  Necessary encroachment into land formerly used for tipping and with known contamination to the north of the sewage treatment works (Albeit a different part to Option 2A). This is now designated as ‘Open Mosaic Habitat’ so there could be ecology issues. The Environmental Appraisal (Appendix D) states that – “Travels through an area of UK Biodiversity Action Plan (BAP) habitat (‘Open mosaic habitats on previously developed land’), which can support rich assemblages of invertebrates; and – Badger setts have been reported near to this route entry option, NW of the sewage works (Mott MacDonald, 2009). However, there have been no more-recent surveys than 2009, so it is possible that badgers may use the site differently or are no longer present”;  Critically, there is a significant incursion into land with Flood Zone 3, which is likely to require careful design of the highway alignment and supporting structure to address concerns from the EA and also occupiers of the adjacent industrial estate affected in part by past flooding events; and

 Townscape impact on residents to the north of the river, notably views for residents at Meadowdrive, Avondale House and Roseneath, whilst users of the River Avon Trail footpath are likely to be impacted also. As with Option 2A, the operational impact of this option is considered separately in the sub-section on traffic modelling. 6.2.3 Option 3A - ‘A4 new junction to Avon Mill Lane’ The Option 3 alignment to the east of Broadmead Lane is shown in Drawing Nos 674726.BP.41.007a and 674726.BP.41.007b. The westward connection to the A4175 via Avon Mill Lane (Variant A) is covered in past commentary on Option 2A. In short there is the impact on the former tip land to the north of the sewage treatment work and the need for a step-change improvement to the capacity of the A4175 Avon Mill Lane junction. As with Option 2A, the roundabout layout shown in Drawing No 674726.BP.41.009 has been the one tested in the network modelling of Option 3A. Option 3 provides the best solution for improved accessibility to the land identified for the North Keynsham SDL. This is because the road alignment shown would pass through land forming the proposed allocation on both sides of the GWML, so improving connectively within the site as well as achieving a direct access to the A4 Bath Road. The junction location with the A4 Bath Road is also less constrained by built development when compared with Pixash Lane and the sensitive issues in seeking to improve this layout (Option 2). A roundabout solution has been developed as shown on Drawing No 674726.BP.41.014. This incorporates flaring to two lane entries on the A4 East and Link Road approaches, although only a single lane entry is considered necessary on the A4 West approach. It is important to note that a signalled junction could be considered as part of on-going scheme design should an Option 3 variant be taken forward as ‘preferred’. However, testing in this OAR assumes a roundabout junction with the A4 Bath Road. Drawing 674726.BP.41.007b shows that achieving the approach height necessary for the bridge structure over the GWML will require an embankment to the south of the railway, and significant earthworks to the north to create a ‘plateau’ necessary to accommodate the junction needed to achieve the sharp change in the horizontal alignment westwards. As shown, the existing road to the small business park would need to be shortened and re-aligned to connect with the link road via the roundabout indicated. The issues with the construction of a new over-bridge to the GWML in this location are set out in the structures assessment in Appendix G. In summary, this states that “At this location the railway is in a shallow cutting about 1.5m deep. The same construction constraint issues apply as for Option 2 bridge alongside Pixash Lane. As the bridge will be at a skew angle of about 30°, the span will increase by 15% to 17.5m, requiring deeper beams. The curved alignment will require a wider bridge to ensure sighting on the inside of the bend” and “Note that in the event of there being railway signal sighting issues on the inside of the bend, the span may have to be increased. Also, the soffit height of the bridge may need to be greater than 5.1m above the rail to enable greater flexibility in the design of the OLE, there being no other local constraint to height. Both of these issues to be agreed with Network Rail would conspire to increase the approach embankments height and length, adversely affecting the cost and viability of this option”. This points to a need for early discussions and consultation with Network Rail to discuss both this over-bridge solution, and indeed the Option 2 alternative by the existing Pixash Lane bridge. Drawing 674726.BP.41.007a shows the proposed continuation of the Option 3 route westwards to Broadmead Lane. The following points are worthy of note:  The existing Pixash Lane bridge is proposed to be closed to vehicular traffic and retained as a pedestrian/cyclist link only. The existing access to Avon Valley Country Park would desirably be sited westwards as indicated, rather than join the link road at the same point as the pedestrian/cycle route from Pixash Lane emerges. This will enable a sheltered right turn ‘ghost island’ to be provided at the new access, with a refuge island located within the approach taper to assist NMU movements between Pixash lane and AVCP; and 40

 Vehicle use of the Broadmead Lane under-bridge would be retained, but in the northbound direction only. This is more important with Option 3, as drivers from East Keynsham are less likely to drive eastwards to the new roundabout to access the link road for journeys to the A4175 North. This is particularly the case in the weekday AM peak hour, when this part of the eastbound A4 can, on occasion, be affected by slow moving/queuing traffic extending from Saltford. This diversion would be required by any drivers using the link road to travel southbound from the A4175 to East Keynsham. However, the westbound section of the A4 Bath Road between the proposed roundabout and Broadmead Roundabout is not subject to any delay of significance in either the weekday AM or PM peak hours. In respect of the section of the route to the east of the Broadmead Lane under-bridge (and interim junction in this location) the Flood Risk/Drainage Assessment (Appendix E) comments that “From the roundabout (at Broadmard Lane) to Bath Road, the route is outside of Fluvial Flood Zones 2 and 3.”. However, in terms of surface water drainage it is noted that “This option requires the greatest volume of attenuation. The route passes through a zone of surface water flood risk near the entrance to the Avon Valley Country Park, but is raised in this section. Culverts or drains will be required to prevent ponding of surface flood water”. In summary, the key risks and impacts with the Option 3A alignment are as follows:  Achieving satisfactory operation at the terminal A4 Bath Road junction. The flows on this part of the A4 here are significant in both directions, whilst exist blocking in the eastbound direction towards Saltford is likely to be risk at times;  Achieving satisfactory vertical alignment between the A4 Bath Road and the proposed over- bridge, given potential uncertainty concerning what headroom above track level Network Rail may ultimately seek to require/impose to accommodate further OLE. This is more of risk with Option 3 than Option 2, where the existing soffit level of Pixash Lane bridge is already a limiting factor with the latter;  Directly affects an existing Site of Nature Conservation Interest just east of Broadmead Lane to the north of the railway (refer to Appendix A - Constraints Plan);  The greatest need (Option 3) for surface water attenuation; mainly due to the extended length of the route eastwards;  Necessary encroachment into land formerly used for tipping and with known contamination to the north of the sewage treatment works. This is now designated as ‘Open Mosaic Habitat’ so there could be ecology issues;  Necessary improvements to the A4175/Avon Mill Lane junction to achieve a ‘step change’ increase in capacity over than assessed as achievable with the Somerdale s106 scheme. This will require significant remodelling of the A4175 approach from the Town Centre, and a high risk of substantive services diversion costs. The services drawings (Appendix F) reveal a concentration of gas, water and Virgin Media apparatus on the north side of the existing junction, all of which is likely to need diversion. Traffic modelling and the operational impact of Option 3A is covered in a subsequent sub-section of this chapter. 6.2.4 Option 3C - ‘A4 new junction to new junction on A4175’ This option comprises the Option 3 alignment to the east of the interim junction with Broadmead Lane just north of the under-bridge, and the Variant C link to the A4175 via the new river bridge thereafter. Discussion on the issues and impacts with both parts of the Option 3C route are not re- iterated here. However, the key impacts and risks are set out below:  Achieving satisfactory operation at the terminal A4 Bath Road junction:

 Achieving satisfactory vertical alignment between the A4 Bath Road and the proposed over- bridge, given potential uncertainty concerning what headroom above track level Network Rail may ultimately seek to require/impose to accommodate further OLE;  Directly affects an existing Site of Nature Conservation Interest just east of Broadmead Lane to the north of the railway (refer to Appendix A - Constraints Plan);  The greatest need (Option 3) for surface water attenuation; mainly due to the extended length of the route eastwards;  Necessary encroachment into land formerly used for tipping and with known contamination to the north of the sewage treatment works (Albeit a different part to Option 2A). This is now designated as ‘Open Mosaic Habitat’ so there could be ecology issues. (refer to the ‘Environmental Appraisal’ - Appendix D);  Significant incursion into land with Flood Zone 3, which is likely to require careful design of the highway alignment and supporting structure to address concerns from the EA and also occupiers of the adjacent industrial estate affected in part by past flooding events; and  Townscape Impact on residents to the north of the river, notably views for residents at Meadowdrive, Avondale House and Roseneath, whilst users of the River Avon Trail footpath are likely to be negatively impacted. As with the other options, highway operation is discussed in a later sub-section under traffic modelling. 6.3 Construction Access This is a very important consideration given to access limitations to the area north of the GWML. As noted in earlier dialogue the Broadmead Lane under-bridge is both narrow and has a height restriction. Furthermore, the Pixash Lane bridge is also ‘single track’, has poor forward visibility and critically cannot accommodate vehicles with a long wheel-base by virtue of its vertical profile. Whichever of the four options is pursued, satisfactory access will need to be provided for large construction plant to enable the accommodation works for the bridge(s) to be undertaken. In view of this, the issue of construction access is discussed in the structures assessment (Appendix G). With respect to the new bridge adjacent to existing at Pixash Lane it is advised in the Appendix G report that “the size of plant able to reach the site is limited by the width and/or height of various existing bridges go under or over the railway. As such, there would be a prerequisite for a link road running westwards to the A4175 to be built in advance as previously mooted (with Option 1). In any event large quantities of fill material are required to bring the road approach ramp on the north side up to the level of bridge deck, and that requirement may best be met by a dedicated haul road”. Clearly the same issue exists with the Option 3 bridge location, although in this case the ‘build’ site would be further east from the A4175. It is clear that the only feasible solution would be to secure agreement from the current occupier of the paper recycling depot (DH Smith) to use the private road running westwards from the Brassmills access, and thereafter construct a haul road to Broadmead Lane. This haul road would impact on the former tip land to the north of the sewage treatment works, and would conceivably be aligned in the same way to the permanent highway works proposed with Variant A (so Options 2A and 3A). This raises some key points affecting cost and the ultimate choice of the link road alignment as follows:  If either Option 2A or 3A was taken forward as the preferred route, the construction of the highway works between Avon Mill Lane and Broadmead Lane to base-course level would, on completion, provide the necessary haul road connection necessary to access and construct the other works to the north of the GWML;  If a Variant C connection to the A4175 was taken forwards (based on either Option 2 or 3), it would still be necessary to construct this haul road from Avon Mill Road. It would, however,

form no part of the permanent works, so would have to be removed afterwards and the land re- instated; and  If there was opportunity, or it became necessary, to acquire the DH Smith site, any temporary haul road connection made to deliver Option 2C or 3C could be upgraded to provide a secondary access route from Avon Mill Lane. Whilst this could be argued as increasing the infrastructure works, it would be necessary to construct the haul road anyway, so up-grade costs would more than likely be balanced by those necessary to remove it and re-instate the land. However, there would be no requirement to upgrade the A4175/Avon Mill Lane junction necessary with Options 2A and 3A. 6.4 Traffic Modelling As noted earlier in this OAR, the network model used for assessing the short-list options was the Keynsham S-Paramics model. Whilst this does not offer the same ability as GBATS to model strategic re-routing of traffic which might occur with the creation of this link, it does enable a much better and more accurate representation of likely future highway operating conditions at junctions within the Town Centre and along the adjacent A4 corridor. This model was calibrated/validated to a 2011 base year for initial work in examining the impact of the Somerdale development, now approved. Future modelling work using this model was used to inform the Core Strategy, and more recently as part of the evidence base at the Place Making Plan EiP in September 2016. The model network includes the whole of the Town Centre, the A4175 between Hicks Gate (A4) and the A431 and the section of the A4 between Brislington and Saltford (Norman Road). It does not directly model the A4 Bath Road/Emery Road junction at Brislington, or the extension of the A4 through the centre of Saltford to the east, both of which can have ‘exit blocking’ effects on traffic leaving the Keynsham area. However, this potential for ‘bottle-necking’ leading to queuing back into the model area is handled by applied restrictions at these exits. In other words, they are not assumed to be ‘free flow’. The extent of the S-Paramics network is shown in Figure 6.1 below:

Figure 6.1: Keynsham S-Paramics Model - Network Extent The assumptions on growth from 2011 to the modelled forecast year of 2029 used for the Reference case (end of Core Strategy/PMP plan period) was previously described in sub-section 3.1.1. This is ‘committed’ growth to 2029 based on sites identified within Keynsham in the Core Strategy and Place Making Plan. Modelling excludes specific consideration of the North Keynsham SDL in the option tests. The overall growth from 2011-2029 has been capped to that identified in TemPRO in line with WebTAG advice. Further information on the traffic modelling undertaken is included in the modelling report in Appendix J. This includes a full comparison of results against the Reference Case, which include two-way traffic volumes on selected links, journey times on selected routes and critically the global network statistics showing data such as ‘total network time’ The latter is the key metric used for monetarised derivation of scheme benefits based on expected savings. Tables 6.1 and 6.2 show the global network statistics obtained for the 7:00-10:00 am and 3:00-7:00 pm periods for the Reference Case and four short-list options.

Output DN OP2A OP2C OP3A OP3C

Total Travel Time (hrs) 2122 1943 1908 1953 1992

Mean Delay per Vehicle (s) 319 292 286 295 299

Total Distance Travelled (m) 72,303,908 72,359,480 71,936,608 72,133,244 72,116,431

% Network Demand Satisfied 99.5% 99.5% 99.5% 99.2% 99.5%

Network Mean Speed (mph) 21 23 23 23 22 Table 6.1: Network performance outputs, morning peak period (07:00 – 10:00)

Output DN OP2A OP2C OP3A OP3C

Total Travel Time (hrs) 6471 5775 5523 5885 5686

Mean Delay per Vehicle (s) 715 585 551 609 572

Total Distance Travelled (m) 151,096,375 155,341,703 156,167,962 154,118,725 155,989,728

% Network Demand Satisfied 97.7% 98.6% 99.5% 98.2% 99.4% Table 6.2: Network performance outputs, evening peak period (15:00 – 19:00)

It is clear from the results that all four options show a substantive saving in overall network travel time over each period considered. In general, the savings with the Variant C alignment connection to the A4175 perform better than those connecting via Avon Mill Lane (Variant A). This is not unexpected as this routing to the A4175 avoids conflict and interaction with other traffic still using Avon Mill Lane. The results also show that alignments based on an Option 2 connection to Pixash Lane at the eastern end perform better than the longer route to the east created with Option 3. This is most likely due to Option 3 being less attractive to drivers routing from the A4175 North to East Keynsham. Tables 6.3 and 6.4 show the two-way flows on selected links with the Reference Case and four link road options. Roads showing a volume increase of more than 100 vehicles are indicated in red, whilst roads with a predicted decrease in flow of more than 100 vehicles are indicated in blue.

Location DN OP2A OP2C OP3A OP3C

1. High Street: Charlton Road to Temple Street (SB one-way section); 466 530 499 524 496

2. High Street: Station Road to Charlton Road; 2876 2769 2861 2781 2819

3. Ashton Way: just south of Charlton Road mini-roundabout; 2615 2487 2636 2472 2567

4. Bath Hill: Avon Mill Lane to Temple Street; 3698 3692 3742 3667 3728

5. B3116 Bath Road: Broadmead Roundabout to Unity Road; 3821 3494 3650 3527 3698

6. B3116 Bath Road: Chandag Road to Wellsway; 3937 3619 3592 3648 3633

7. Bath Hill: Wellsway to Avon Mill Lane; 4881 4442 4278 4483 4314

8. Avon Mill Lane: Bath Hill to Vandyke Avenue; 2079 1728 1453 1785 1520

9. Avon Mill Lane: A4175 to Brassmills; 1965 2134 1340 2124 1407

10. A4 Bath Road: Pixash Lane to Broadmead Roundabout; 6719 6539 6460 6496 6476

11. A4 Keynsham Bypass; 5899 5847 5913 5816 5937

12. LINK ROAD: North of Broadmead Lane under-bridge; 0 533 798 464 734

13. LINK ROAD: Broadmead Lane to Pixash Lane; 0 185 299 143 241

14. LINK ROAD: Pixash Lane to A4 Bath Road (Options 3A and 3C Only) 0 0 0 143 240 Table 6.3: Modelled traffic volumes (two-way), morning peak period (07:00-10:00)

Location DN OP2A OP2C OP3A OP3C

1. High Street: Charlton Road to Temple Street (SB one-way section); 921 1088 1139 1042 1089

2. High Street: Station Road to Charlton Road; 4120 4308 4445 4233 4347

3. Ashton Way: just south of Charlton Road mini-roundabout; 3353 3154 3230 3203 3281

4. Bath Hill: Avon Mill Lane to Temple Street; 5575 5818 5877 5727 5831

5. B3116 Bath Road: Broadmead Roundabout to Unity Road; 5758 5270 5456 5359 5575

6. B3116 Bath Road: Chandag Road to Wellsway; 5564 5102 5174 5178 5299

7. Bath Hill: Wellsway to Avon Mill Lane; 6773 6350 6316 6412 6445

8. Avon Mill Lane: Bath Hill to Vandyke Avenue; 3108 2697 2420 2817 2598

9. Avon Mill Lane: A4175 to Brassmills; 3102 3516 2477 3448 2651

10. A4 Bath Road: Pixash Lane to Broadmead Roundabout; 9211 9164 9042 9126 9289

11. A4 Keynsham Bypass; 8563 8579 8821 8525 8845

12. LINK ROAD: North of Broadmead Lane under-bridge; 0 828 1,057 669 844

13. LINK ROAD: Broadmead Lane to Pixash Lane; 0 187 477 186 293

14. LINK ROAD: Pixash Lane to A4 Bath Road (Options 3A and 3C Only) 0 0 0 187 283 Table 6.4: Modelled traffic volumes (two-way), evening peak period (15:00-19:00)

Both sets of peak period results show that none of the link road options are expected to reduce flows along the High Street, Ashton Way, Station Road or the section of Bath Hill between Avon Mill Lane and Temple Street. This is not unexpected, as the route used now by drivers for the movement between the A4 East and A4175 North is principally Avon Mill Lane, which is just east of the Town Centre. As expected, all link road options offer relief here, as well as the section of Bath Hill between

Avon Mill Lane and Wellsway and the B3116 Bath Road. This is consistent with previous work looking at the likely operating impact of such a potential link road in 2015. In the PM peak period the increases shown on some links in the Town Centre are due to ‘congestion relief’ afforded by all the link road options. Table 6.2 shows that the overall vehicle demand able to fully complete journeys through the network by the end of the assessment period is increased, which will serve to increase the ‘actual’ flows recorded in locations where constrained by congestion in the Do-Nothing case. The High Street is the key case in point, but also the section of Bath Hill between Avon Mill Lane and Temple Street. The results for the link road (Locations 12-14) show that the Variant C options (2C and 3C) to connect with a new junction on the A4175 attract more traffic than options using Avon Mill Lane at the western end. Comparison of locations 12 and 13 show that a significant flow joins the route via the Broadmead Lane under-bridge (NB only), as there would otherwise be no change in the two-way figures in these two locations. In the AM peak period this amounts to anything between 62-69% of the total two-way traffic expected to use the link road section immediately north of the underbridge, and 55-77% of the two-way flow in the PM peak period. The results show clearly that potential utility of the link road is very dependent on how attractive it is to drivers making the movements between East Keynsham and the A4175 North, accepting that ‘through’ traffic between the A4 East and the A4175 North will transfer as all routes will be more attractive to these drivers than using Avon Mill Lane and the B3116 as now. This does of course ignore the additional generated traffic usage which would occur on the link with the North Keynsham SDL. 6.5 Cost Estimating and Economic Assessment 6.5.1 Cost Estimating A breakdown of the scheme costs by ‘Series’ and showing contingency/risk allowances made is included as Appendix K. Costs for the various options have been estimated using the standard Method of Measurement for Highway Works determined using a mixture of direct CAD measurements and manual take offs. Wherever possible, rates have been taken from the B&NES / Skanska Highway Maintenance and Improvement Works Term Maintenance Contract Schedule of Rates. Statutory undertaker (C2) records (Appendix F) have been used to provide an informed level of contingency allowance for services diversion or in-site protection works. All cost estimating done has been independently reviewed by sub-contractor Currie and Brown, which is a global leader in cost management/ quantity surveying services. The effective management of risk and uncertainty through accurate evaluation and proactive mitigation of risks will be critical to the successful delivery of the link road scheme. As such, a Quantified Risk Assessment (QRA) has been be undertaken in line with the WebTAG guidance on Scheme Costs (DfT TAG Unit A1.2, November 2014). The main purpose of this QRA has been to support the construction cost estimating of the scheme options by predicting the level of risk contribution or ‘risk pot’, to ensure that the final estimates have a defined level of confidence in terms of contingency pricing. This allows for uncertainty in unplanned and unforeseen additional cost items that cannot be included in the project costs. Potential risks with required mitigation in the fluvial floodplain and works involving construction over land formerly used for tipping are cases in point. The outcome construction costs (2018 base) of the four options incorporating land acquisition, preparation and supervision costs are estimated to be as follows:  Option 2A: £27.32M;  Option 2C: £50.10M;  Option 3A: £23.89M; and

 Option 3C: £46.58M 6.5.2 Economic Assessment Derivation of scheme benefits is based on the travel time savings obtained from the S-Paramics model for the weekday periods 7:00-10:00 am and 3:00-7:00 pm. It is thus important to note that potential network benefits of the link road in the weekday inter-peak period 10:00 am to 3:00 pm are not considered. Vehicle operating cost savings and accident cost savings have similarly not been accounted for in the economic assessment. The benefits stream has been assessed for a 60-year period from an assumed scheme Opening Year of 2029. For the purposes of the economic assessment an appropriate level of Optimism Bias has been made in line with the Stage of the project and level of design (Stage 1: 44%). A EXCEL spreadsheet approach has been used to estimate the Present Value of Benefits (PVB), the Present Value of Costs (PVC) and the Benefit Cost Ratio (BCR) for each of the short-listed options. Standard WebTAG values have been used for journey purpose splits in the weekday AM and PM peak periods and corresponding values of time (VOT). The outcome BCR estimates show the following ‘Value for Money’ categorisation for the four options:  Option 2A: High Value for Money;  Option 2C: Medium Value for Money;  Option 3A: High Value for Money; and  Option 3C: Low Value for Money. This shows that, whilst the ‘Variant C’ schemes perform better in traffic terms in attracting greater usage, and hence improved relief benefit to roads within Keynsham, the additional costs in constructing what is a much more expensive alignment crossing the River Avon to a new junction with the A4175 are not out-weighed by these additional benefits.

7 TAG Appraisal Stage 1- Early Assessment and Sifting Tool Tables 7.1 Introduction DfTs Early Assessment and Sifting Tool is a defined step in the appraisal process set out in TAG. The Early Assessment and Sifting Tool is an early comparison of options and tools being considered, prior to the more detailed appraisal which will enable recommendations to be made for funding decisions. DfT sets out that the Early Assessment and Sifting Tool should be used to:  Help refine options by highlighting adverse impact or unanticipated consequences;  Compare options, for example, within or across modes, geographical areas and networks;  Identify trade-offs between objectives aiding package development;  Filter the number of options, i.e. discount non-runners early on to ease the appraisal burden and avoid resources being spent unnecessarily; and  Identify key uncertainties in the analysis and areas where further appraisal efforts should focus. A full guidance document supporting the Tool is available to view at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/4475/east- guidance.pdf. When undertaking an Early Assessment and Sifting Tool appraisal, it is often at a very early stage in the scheme development work and therefore only high-level information is available. The four short listed options have been assessed using the Early Assessment Sifting Tool, with results presented in the following figures, and further details outlined in the next chapter.

8 Early Assessment and Sifting Tool - Supporting Information

This chapter presents any supporting information which has been used to complete the DfT Early Assessment and Sifting Tool scoring. 8.1 Strategic Case 8.1.1 Scale of Impact Table 8.1 shows the scale of impact of the scheme options.

Option Scale of Impact Justification 2A - Pixash to Avon Mill Lane 4 – Expected to significantly alleviate the problem See scoring in Table 8.3 2C – Pixash to new junction on A4175 4 – Expected to significantly alleviate the problem See scoring in Table 8.3 3A – A4 new junction to Avon Mill Lane 4 – Expected to significantly alleviate the problem See scoring in Table 8.3 3C – A4 new junction to new junction on 4 – Expected to significantly alleviate the problem See scoring in Table 8.3 A4175 Table 8.1: Scale of Impact

Response options are: 1 – Very small overall impact – would have a very small positive impact, possibly with undesirable consequences 2 – Minor impact – Would have a modest overall impact 3 – Moderate impact – Expected to have a reasonably significant impact on the problem identified 4 – Significant impact – Expected to significantly alleviate the problem 5 – Very significant impact – Expected to alleviate the problem

8.1.2 Fit with wider transport and government objectives Regional objectives are outlined within the WoE LEP SEP and JTS. Strategic objectives outlined within the WoE LEP SEP are:  Create the right conditions for business to thrive. Give confidence and certainty to our investors to attract and retain investment to stimulate and incentivise growth.  Ensure a resilient economy, which operates within environmental limits. That is a low carbon and resource efficient economy, increases natural capital, and is proofed against future environmental, economic and social shocks.  Create places where people want to live and work, through delivery of cultural infrastructure and essential infrastructure, including broadband, transport and housing to unlock suitable locations for economic growth.  Shape the local workforce to provide people with skills that businesses need to succeed and that will provide them with job opportunities.  Ensure all our communities share in the prosperity, health and well-being and reduce the inequality gap. JTS (Final Report, October 2017) objectives include:  EC2: Improve the resilience of road and rail networks to incidents and the impacts of climate change.  EC4: Deliver the transport infrastructure capacity needed to enable job creation and business growth.  CA1: Provide a transport network which is low carbon and resource efficient in operation.  AC1: Improve access for all to employment, education and training.  EV2: Minimise the impacts of transport and travel on the rural environment. The proposed link road will stimulate growth and support new housing delivery at the proposed Keynsham SDL site and all options therefore largely support the objectives of the WoE LEP SEP. Options 3A and 3C are closer to the proposed SDL land in Keynsham, and therefore provide a more direct access. All options are located within the Green Belt, and therefore impact on the natural environment. The options also do not encourage low carbon transport or provide a low carbon transport network, which are objectives of the JTS. Table 8.2 shows how the scheme options fit with the wider transport and government objectives.

Option SEP Justification JTS Goals objectives Support Reduce Improve Better Promote economic carbon quality of safety, accessibility growth emissions life and health & healthy security natural env’t 2A - Pixash to 4 Moderate/ Stimulates growth, ensures 4 2 2 3 5 High fit Avon Mill High fit resilience, delivers Moderate/ Moderate/ Moderate/ Moderat Lane infrastructure capacity. High fit Low fit Low fit – e fit – relieved cycle Level of benefit depends on pressures lanes/fo what is done at A4175/Avon on otpath Mill Lane junction. Keynsham provision Located within the Green Belt. routes, impact on Green Belt 2C – Pixash 4 Moderate/ Stimulates growth, ensures 5 High fit 2 2 3 5 High fit to new High fit resilience, delivers Moderate/ Moderate/ Moderat junction on infrastructure capacity. Low fit Low fit – e fit – A4175 relieved cycle Located within the Green Belt. pressures lanes/fo on otpath Keynsham provision routes, impact on Green Belt 3A – A4 new 4 Moderate/ Stimulates growth, ensures 4 2 2 3 5 High fit junction to High fit resilience, delivers Moderate/ Moderate/ Moderate/ Moderat Avon Mill infrastructure capacity. High fit Low fit Low fit – e fit – Lane relieved cycle Level of benefit depends on pressures lanes/fo what is done at A4175/Avon on otpath Mill Lane junction. Keynsham provision Provides a direct access to the routes, proposed SDL site. impact on Green Belt Located within the Green Belt. 3C – A4 new 4 High fit Stimulates growth, ensures 5 High fit 2 2 3 5 High fit junction to resilience, delivers Moderate/ Moderate/ Moderat new junction infrastructure capacity. Low fit Low fit – e fit – on A4175 relieved cycle Provides a direct access to the pressures lanes/fo proposed SDL site. on otpath Located within the Green Belt. Keynsham provision routes, impact on Green Belt Table 8.2: Fit against transport and government objectives

Response options are: 1 – Low fit, 5 = High fit 8.1.3 Fit with scheme objectives The scheme options are all seeking to address the same problems and meet the same objectives. Finalised general scheme objectives are:  Improve travel choices for movement, facilitating park and bus (and possibly rail), park and cycle, and modal interchange.  Unlock capacity for sustainable urban growth and new job creation in the Bristol urban area.

 Minimise the impact of additional traffic and proposed infrastructure on the environment.  Improve transport network resilience and journey time reliability. Table 8.3 shows how the scheme options fit with the scheme objectives. Further information on the fit against scheme objectives is included in Appendix H (Long List Option Sifting Tables).

Option Improve transport Provide effective Reduce traffic flows Deliver improved facilities for Enable the network resilience access to the new and relieve traffic pedestrians, cyclists and effective improvement and and journey time development pressures on routes public transport in North retention of reliability area in North through Keynsham Keynsham traffic reduction Keynsham (SDL) measures in the Town Centre 2A - 4 – Benefit will 4 – Link will be 4 –Traffic relief on 5 – Stopping up of Pixash Lane 3 – Will depend Pixash depend on what is closer to the SDL the B3116 Bath bridge will enable this to be used on how well the to Avon done at the land. Road, Bath Hill and by NMUs. Signalisation of length of Avon Mill A4175/Avon Mill Avon Mill Lane. A4/Pixash Lane junction could Mill Lane can be Lane Lane junction include controlled crossing relieved of traffic facilities. Reduced traffic through or operating Keynsham increases speeds for conditions bus. improved. 2C – 5 - Improved 4 – Link will be 4 –Traffic relief on 4 – Stopping up of Pixash Lane 4 – Likely, as this Pixash journey time and closer to the SDL the B3116 Bath bridge will enable this to be used option is likely to to new reliability between land. Road, Bath Hill and by NMUs. Signalisation of reduce traffic junction east and north Avon Mill Lane. A4/Pixash Lane junction could using the whole on Keynsham. include controlled crossing of Avon Mill Lane. A4175 facilities. More difficult to connect with High Street as junction further north than 2A. Reduced traffic through Keynsham increases speeds for bus. 3A – A4 4 – Benefit will 5 – Link will 4 –Traffic relief on 5 – Stopping up of Pixash Lane will 3 – Will depend new depend on what is provide direct the B3116 Bath enable this to be used by NMUs. A on how well the junction done at the access to the SDL Road, Bath Hill and controlled crossing over A4 Bath length of Avon to Avon A4175/Avon Mill land. Avon Mill Lane. Road nr Pixash Lane could be Mill Lane can be Mill Lane junction considered. Reduced traffic relieved of traffic Lane through Keynsham increases or operating speeds for bus. conditions improved. 3C – A4 5 - Improved 5 – Link will 4 –Traffic relief on 4 – Stopping up of Pixash Lane will 4 – Likely, as this new journey time and provide direct the B3116 Bath enable this to be used by NMUs. A option is likely to junction reliability between access to the SDL Road, Bath Hill and controlled crossing over A4 Bath reduce traffic to new east and north land. Avon Mill Lane. Road nr Pixash Lane could be using the whole junction Keynsham. considered. More difficult to of Avon Mill Lane. on connect with High Street as A4175 junction further north than 2A. Reduced traffic through Keynsham increases speeds for bus Table 8.3: Fit with Scheme Objectives

Response options are: 1 – Low fit, 5 = High fit

8.1.4 Key uncertainties The key risks for the project are outlined in Section 8.3.5 (Key Risks). There are a number of uncertainties associated with the built environment, existing structures and funding for each option. The feasibility of any option taken forward would need to be confirmed at a later stage, within the Outline Business Case.

8.1.5 Degree of consensus over outcomes Table 8.4 shows the known degree of consensus about the scheme options. Option Early Assessment Justification and Sifting Tool Response 2A - Pixash to Avon Mill 3 Some consultation has taken place on Variant A with some agreement. Lane ‘A4 to Avon Mill Lane Link’ was included in the JTS, which was consulted on. 2C – Pixash to new 2 Variant C of ‘A4 to Avon Mill Lane Link’ was not included in the JTS. junction on A4175 3A – A4 new junction to 3 Some consultation has taken place on Variant A with some agreement. Avon Mill Lane ‘A4 to Avon Mill Lane Link’ was included in the JTS, which was consulted on. 3C – A4 new junction to 2 Variant C of ‘A4 to Avon Mill Lane Link’ was not included in the JTS. new junction on A4175

Table 8.4: Degree of consensus over outcomes 8.1.6 Summary of strategic case A review of the headings under the strategic case indicate that all options fit in with the wider public policy objectives of economic growth and relieving congestion. Option 3 would provide a direct access to the proposed Keynsham SDL. All Options have an impact on carbon emissions and the natural environment, including the Green Belt. All four options provide substantive saving in overall network travel time over time periods considered. All options provide similar journey time benefits with improvement in journey time on routes such as the B3116 Bath Road and Avon Mill Lane. Traffic modelling results suggest that Variant C alignments have the greatest scope for attracting traffic and hence relieving routes expected to be congested in the future, such as the B3116 Bath Road and Avon Mill Lane. 8.2 Economic Case 8.2.1 Economic growth The West of England has a substantial economic growth agenda which is being developed through the Strategic Economic Plan. The current share of national economic growth (GVA) is the highest of any core city region at 3.1%. The overall vision is to build on this economic growth through a range of interventions including improving access to major employment sites for the skilled workforce catchment. The population is expected to exceed 1.1 million by 2026, and new housing sites will need to be developed to accommodate this growth. The city region needs to make sure its transport infrastructure is not only fit for purpose, but has the ability to respond to increasing demand and therefore maximise potential for continued economic growth. 2,150 of the houses outlined in the BANES Cores Strategy are to be provided in Keynsham, of which 1,600 will be provided through Strategic Sites. 1,600 new jobs will also be created between 2011 and 2029 primarily by increasing the stock of office floorspace in Keynsham, complemented by an extension to the Broadmead/ Ashmead/Pixash industrial Estate. All scheme options would improve resilience by providing an alternative route across Keynsham in the event of incidents. All scheme options would have a positive impact on access to jobs and training and a positive impact on access to local services. 57

All options will improve access to the proposed SDL, however Options 3A and 3C are further east and would therefore cut through the site and provide a direct access. An accident analysis has not been undertaken for options at this stage. However, all options relieve pressure on other roads in Keynsham, and improve reliability overall. It is therefore envisaged that all options will lead to a decrease in incidents.

Impact to Option Impact to end Impact to cost of Wider transport Impact to Delivery of Accessibility Overall to end journey travel (time & economic reliability & incidents housing changes RAG time money) impacts resilience 2A - Pixash to Decrease Decrease Improve Likely decrease Required to Improved Improve Green Avon Mill Lane serve access to proposed SDL safeguarded core strategy site 2C – Pixash to Decrease Decrease Improve Likely decrease Required to Improved Improve Green new junction on serve access to A4175 proposed SDL safeguarded core strategy site 3A – A4 new Decrease Decrease Improve Likely decrease Required to Improved Improve Green junction to Avon serve access to Mill Lane proposed SDL safeguarded core strategy site 3C – A4 new Decrease Decrease Improve Likely decrease Required to Improved Improve Green junction to new serve access to junction on proposed SDL safeguarded A4175 core strategy site

Table 8.5: Economic growth

8.2.2 Carbon emissions The impacts of the scheme options are as follows:  Increase in the volume of non-public transport trips, due to additional highway provision.  Significant construction work required.  Reduction in vehicle-km and stop-start driving due to reduction in congestion.  Some decongestion benefits (associated with other corridors in Keynsham such as Avon Mill Lane).  Likely increase in carbon emissions. Overall effect on carbon emissions Option Vehicle km change Significant Lower carbon Fuel per Non-traded Traded construction fuel vehicle km (diesel, (electric) work required petrol and bio fuel) 2A - Pixash to Decrease from reduced Yes No change Decrease Likely Likely no Avon Mill congestion increase change Lane 2C – Pixash to Decrease from reduced Yes No change Decrease Likely Likely no new junction congestion increase change on A4175 3A – A4 new Decrease from reduced Yes No change Decrease Likely Likely no junction to congestion increase change Avon Mill Lane 3C – A4 new Decrease from reduced Yes No change Decrease Likely Likely no junction to congestion increase change new junction on A4175

Table 8.6: Carbon Emissions 8.2.3 Local environment Table 8.7 shows the impact of the respective options on the local environment in terms of air quality and noise and Table 8.8 illustrates the impact on the natural and urban environment more generally. These tables reflect the results of the WebTAG compliant environmental assessment, the results of which are summarised in the Environmental Appraisal Report (CH2M, 2018: North Keynsham: A4 to A4175 Link Road Environmental Appraisal).

Option Impact to Impact to existing AQMAs Is it likely scheme Impact to noise Impact to natural and Environmental value Overall air quality will create an urban environment of land affected RAG AQMA 2A - Pixash to Avon Positive No significant change to traffic No There are no council designated Negative Low Amber Mill Lane flows through Keynsham High priority Noise Action Plan locations See Table 8.8 Street AQMA in Keynsham.

2C – Pixash to new Positive No significant change to traffic No There are no council designated Negative Low Amber junction on A4175 flows through Keynsham High priority Noise Action Plan locations See Table 8.8 Street AQMA in Keynsham.

3A – A4 new junction Positive No significant change to traffic No There are no council designated Negative Low Amber to Avon Mill Lane flows through Keynsham High priority Noise Action Plan locations See Table 8.8 Street AQMA in Keynsham.

3C – A4 new junction Positive No significant change to traffic No There are no council designated Negative Low Amber to new junction on flows through Keynsham High priority Noise Action Plan locations See Table 8.8 A4175 Street AQMA in Keynsham.

Table 8.7: Local environmental impacts

Option Water Quality Flooding Landscape Ecology Visual People and Heritage Community 2A - Pixash to High impact Medium impact Medium impact Medium impact Medium impact Low impact Low impact Avon Mill Lane Passes close to existing and Lies partially within A section of woodland, This route will bisect Landscape already Scheme does Does not directly impact on historic landfill sites – surface National Flood Zone 2 important to local landscape Broadmead Field SNCI industrialised along not bisect any designated heritage water drainage could and partially within character, could be lost. This and two UK BAP Priority most of route - no communities assets. However, it passes potentially mobilise the functional mitigates the visual impacts Habitats. significant additional Some PROW close to Grade II listed contaminants associated with floodplain of the River arising from the industrial Potential badger setts impacts predicted in the area Pixash Lane Bridge and the landfill sites Avon complex nearby views of it from the railway could be affected No landscape designated sites Could also impact present biodiversity in an area of deciduous woodland.

2C - Pixash to High impact Medium impact Medium impact Medium impact Medium impact Low impact Low impact new junction on Crosses the River Avon (which Lies within National Landscape already This route will bisect Views for residents Scheme does As 2A A4175 is locally designated for Flood Zones 2 and 3 industrialised – no significant Broadmead Field SNCI and River Avon not bisect biodiversity) and a small additional impacts predicted River Avon SNCI and two leisure users are communities watercourse – potential for No landscape designated sites UK BAP Priority Habitats likely to be Some PROW construction works or present Potential badger setts negatively impacted. in the area operational surface water nearby drainage to impact river water quality 3A - A4 new High impact Medium impact Medium impact Medium impact Medium impact Low impact Low impact junction to As 2A As 2A As 2A As 2A As 2A As 2A This route option does not Avon Mill Lane directly impact on any designated heritage assets. However, it passes close to a Grade II listed milestone 3C - A4 new High impact Medium impact Medium impact Medium impact Medium impact Low impact Low impact junction to new As 2C As 2C As 2C As 2C As 2C As 2C As 3A junction on Also, Manor Road A4175 Community Woodland Local Nature Reserve and Stidham farm SSSI are located nearby. Table 8.8: Natural and Urban Environment

8.2.4 Socio-distributional and regionals impacts Table 8.9 shows the likely socio-distributional and regional impacts of the options. All of the options will have a similar impact on the Keynsham and wider population. The scheme will improve accessibility and offer town centre traffic relief. North and central areas of Keynsham do not have high proportions of children, disabled people, Black and Minority Ethnic communities, people without access to a car or people on low incomes. Keynsham does have a number of 2011 census ‘Super Output Areas’ (SOA) in the top 20% for populations over 65. There should be a slight positive impact on this group through improved accessibility. There are no few households adjacent to the proposed options, so impacts on categories such as severance and security will be minimal. It is noted, however, that there is a direct impact on one property associated with the necessary improvement of the A4 Bath Road/Pixash Lane junction with either Options 2A or 2C. There are also residential moorings along the south bank of the River Avon which would be affected by a variant C connection to the A4175 (Options 2C and 3C).

Option SDI Justification

2A - Pixash to Slight positive Keynsham has a number of SOAs in top 20% for population over 65. Improved accessibility from Avon Mill Lane new link road. 2C – Pixash to Slight positive Keynsham has a number of SOAs in top 20% for population over 65. Improved accessibility from new junction on new link road. A4175 3A – A4 new Slight positive Keynsham has a number of SOAs in top 20% for population over 65. Improved accessibility from junction to Avon new link road. Mill Lane 3C – A4 new Slight positive Keynsham has a number of SOAs in top 20% for population over 65. Improved accessibility from junction to new new link road. junction on A4175

Table 8.9: Social distributional impacts

Option Social distributional Regeneration Regional imbalance Economic growth Overall RAG impact 2A - Pixash to Avon Mill Positive No change N/A – strong region Positive Amber/green Lane 2C – Pixash to new junction Positive No change N/A – strong region Positive Amber/green on A4175 3A – A4 new junction to Positive No change N/A – strong region Positive Amber/green Avon Mill Lane 3C – A4 new junction to Positive No change N/A – strong region Positive Amber/green new junction on A4175

Table 8.10: Regional impacts 8.2.5 Well being The well-being assessment considers Severance, Physical Activity, Changes to Accidents, Impact to crime/fear of crime and Access to goods, service, people and place. These matters are considered in turn. Impacts

Physical Changes Impact to Access to goods, Option Severance Activity to crime/fear of service, people and Terrorism Overall RAG Level Accidents crime place 2A - Pixash Slight positive Slight Slight No change Slight positive No impact Amber/green to Avon Mill increase decrease Lane 2C – Pixash Slight positive Slight Slight No change Slight positive No impact Amber/green to new increase decrease junction on A4175 3A – A4 new Slight positive Slight Slight No change Slight positive No impact Amber/green junction to increase decrease Avon Mill Lane 3C – A4 new Slight positive Slight Slight No change Slight positive No impact Amber/green junction to increase decrease new junction on A4175 Table 8.11: Impacts on well being 8.2.6 Value for Money The capital and revenue costs have been compared to the scale of benefits to estimate likely Value for Money. Value for Money categorisation is as follows:  Poor – Benefit to Cost Ratio less than 1  Low - Benefit to Cost Ratio between 1 and 1.5  Medium - Benefit to Cost Ratio between 1.5 and 2  High - Benefit to Cost Ratio between 2 and 4  Very High - Benefit to Cost Ratio greater than 4

Option Value for Money Categorisation

2A - Pixash to Avon High value for money Mill Lane 2C – Pixash to new Medium value for money junction on A4175 3A – A4 new junction High value for money to Avon Mill Lane 3C – A4 new junction Medium value for money to new junction on A4175

Table 8.12: Value for Money Categorisation 8.2.7 Summary of economic case The work undertaken indicates that Options 2A and 3A offer high value for money, whilst Options 2C and 3C offer medium value for money. 8.3 Managerial Case 8.3.1 Implementation Timetable All scheme options have the same proposed implementation timetable. A preferred scheme option would need to be included in LTP4, and delivered after 2026 (the LTP3 period). All scheme options have all therefore been scored 6 (5-10 years). 8.3.2 Public acceptability Consultation on the JTS revealed that the majority of people support the delivery of improved road infrastructure. The scheme is therefore not expected to be controversial to residents in Keynsham. However, consultation on the scheme options presented in this OAR has not taken place. Options 2C and 3C may not be acceptable to the Environment Agency as they cross the Broadmead floodplain. In relation to the WECA Joint Spatial Plan, the Agency commented “The Agency would advise that any development will be required to avoid the Keynsham Hams and Broadmead floodplains”. Further detail on comments made by the Agency are included within Appendix E. Option Level of public Justification acceptability 2A - Pixash to Avon 3 Not expected to be controversial but no specific consultation has Mill Lane taken place. 2C – Pixash to new 2 Not expected to be controversial but no specific consultation has junction on A4175 taken place. Could be objections from the EA. 3A – A4 new junction 3 Not expected to be controversial but no specific consultation has to Avon Mill Lane taken place. 3C – A4 new junction 2 Not expected to be controversial but no specific consultation has to new junction on taken place. Could be objections from the EA. A4175 Table 8.13: Public acceptability

Response options are: 1 – Low, 5 = High 8.3.3 Practical feasibility The assessment of practical feasibility of each of the options has been based on the previous work undertaken to date, in particular a desk based assessment of constraints, structures, ground 65

conditions and services, which are included as Appendices. A number of practical issues have been identified, for example Appendix E (Flooding) outlines that Options 2C and 3C involve a new crossing over the River Avon, with a significant proportion of the alignment through Flood Zones 2 and 3. Flooding issues shall be further investigated and compensatory flood storage area would be required. For all options, the mechanism for construction of a bridge over railway line would need to be agreed with Network Rail. All options would require planning permission before construction could begin. All options are located within the Green Belt and national planning policy outlines that a scheme in the Green Belt should not be approved except in “very special circumstances”. However, the new Local Plan will consider north Keynsham SDL and may set out a new Green Belt boundary. Provision of a new or improved crossing over the railway will be critical to ensuring adequate connectivity to support the SDL. All options would be delivered, operated and maintained by BANES council, who have a strong track record in delivering major projects. As the options are refined and further technical work is undertaken, the extent and detail of the practical feasibility will be better known. Option Level of practical feasibility Comments

2A - Pixash to 3 – Moderate Would require planning permission. Assessment of constraints was Avon Mill solely desk based at this stage. Bridge construction to be agreed Lane with Network Rail. 2C – Pixash to 3 – Moderate Would require planning permission. Assessment of constraints was new junction solely desk based at this stage. Significant proportion of the on A4175 alignment through Flood Zones 2 and 3, may not be acceptable to EA. Bridge construction to be agreed with Network Rail.

3A – A4 new 3 – Moderate Would require planning permission. Assessment of constraints was junction to solely desk based at this stage. Bridge construction to be agreed Avon Mill with Network Rail. Lane 3C – A4 new 3 – Moderate Would require planning permission. Assessment of constraints was junction to solely desk based at this stage. Significant proportion of the new junction alignment through Flood Zones 2 and 3, may not be acceptable to on A4175 EA. Bridge construction to be agreed with Network Rail. Table 8.14: Practical feasibility

Response options are: 1 – Low, 5 = High 8.3.4 Quality of Supporting Evidence To date, the scheme options have been developed to establish feasibility. Consideration of options have been informed by the JTS and technical work undertaken to date including traffic modelling work outlined in Appendix J. The level of detail considered to complete the following has been taken into consideration:  Baseline information – desk based – appropriate for this stage of work;  Structures – desk based – appropriate for this stage of work;  Costs – high level with considerable levels of risk applied - appropriate for this stage of work;  Feasibility – high level - appropriate for this stage of work;  Impacts – high level - appropriate for this stage of work;  Traffic modelling – fairly detailed - taken from an existing traffic model;

As a result, the quality of supporting evidence for all options has scored 4 overall (good level of supporting evidence, possibly including some modelling and/or sensitivity testing demonstrating robust outcomes). 8.3.5 Key risks The key risks for the project include:  Need for the scheme to be prioritised in the WoE;  Need to secure funding and include scheme within Local Transport Plans;  Feasibility of any preferred option to be confirmed in further work, including an Outline Business Case;  Impacts of the scheme exceed current modelled impacts and require additional improvements;  Risks associated with the construction of new structures;  Land take required, and ownership of required land;  Impact on designations such as Civic Amenity Site and Site of Nature Conservation Interest;  Additional environmental mitigation required following further work;  Relevant consents to be secured;  Impact on geology and ground conditions, (including the Open Mosaic Habitat);  Impact on National Flood Zones 2 and 3;  Public support unknown;  Inflated or additional scheme costs, including land purchase and utilities diversion; and  Lack of resources (people, material, expertise, not funding) to progress the scheme.

8.3.6 Summary of management case In summary, most scheme options are considered achievable and thus have a ‘management case’. Public consultation on the options has not yet been undertaken, although the scheme was included within the JTS, which did undergo a period of public consultation. 8.4 Financial Case 8.4.1 Affordability The estimated cost of scheme options is outlined in Table 8.16. All options require significant investment, but this is broadly equivalent to a number of other major projects recently delivered. Options 2C and 3C are more than double the cost of Options 2A and 3A, due to the additional length of carriageway required to link with A4175, and the requirement for a new bridge over the River Avon. Option Affordability Justification

2A - Pixash to Avon Mill Lane 4 JTLP3 includes 11 major transport schemes worth £600m of investment. 2C – Pixash to new junction on 3 JTLP3 includes 11 major transport schemes worth £600m of A4175 investment. 3A – A4 new junction to Avon 4 JTLP3 includes 11 major transport schemes worth £600m of Mill Lane investment. 3C – A4 new junction to new 3 JTLP3 includes 11 major transport schemes worth £600m of junction on A4175 investment. Table 8.15: Affordability 1 = Not Affordable, 5 = Affordable

8.4.2 Capital Cost (£m) For the purpose of this Early Assessment and Sifting Tool appraisal estimated capital costs for the scheme options are presented in Table 8.16.

Option Total Capital Cost (£m)

2A - Pixash to Avon Mill Lane £27.3 2C – Pixash to new junction on A4175 £50.1 3A – A4 new junction to Avon Mill Lane £23.9 3C – A4 new junction to new junction on A4175 £46.6 Table 8.16: Capital cost (£m) 8.4.3 Revenue costs Revenue costs are not available at this stage. 8.4.4 Cost Profile Capital costs are included in Table 8.16. Cost profile information is not available at this stage. 8.4.5 Overall cost risk and other costs Costs are currently high level, and include fees, considerable contingency and land purchase. The scheme costs are all effected by the following risks:  Land purchase;  Environmental mitigation;  Environmental, utilities and other constraints – only desk based review to date;  Delays to implementation timetable;  Lack of resources; and  Funding secured and timing.

Option Overall cost risk

2A - Pixash to Avon Mill Lane 3 – Medium risk 2C – Pixash to new junction on 3 – Medium risk A4175 3A – A4 new junction to Avon Mill 3 – Medium risk Lane 3C – A4 new junction to new 3 – Medium risk junction on A4175 Table 8.17: Cost Risk

Cost risk has been assessed on a scale of “1 high risk” to “5 low risk”. 8.4.6 Summary of financial case In summary, all schemes are financially affordable and thus have a ‘financial case’. The cost of Options 2C and 3C is higher due to the requirement of a new River Avon crossing. 8.5 Commercial Case 8.5.1 Procurement The scheme would be delivered by BANES Council, and standard procurement routes would be adhered to. BANES Council has a strong record in procuring and delivering major infrastructure projects.

8.5.2 Flexibility of option All scheme options are deemed to be inflexible due to surrounding constraints, which have been outlined in previous sections. Scheme options have already been refined to present the most feasible options in each location. All options have therefore been scored 1 - ‘Static’. 8.5.3 Funding sources Potential funding sources include:  Local Major Funding;  Local Growth Fund; and  Developers (via S106 Agreements and/or CIL). These funding sources would be applicable for all scheme options. 8.5.4 Income generation None of the scheme options would generate an income. 8.5.5 Summary of commercial case In summary all scheme options are considered commercially viable, thus have a ‘commercial case’. 8.6 Summary In summary, the key strengths for the Business Case are:  Need for the scheme identified in emerging policy;  Increased capacity and resilience of road network;  Provision of a new access, necessary to deliver north Keynsham SDL;  Delivery of improved facilities for pedestrians, cyclists and effective public transport in North Keynsham;  High BCR of Options 2A and 3A.

Option Strategic case Economic case Financial case Commercial case Management case (£m) 2A - Pixash to Moderate/High High BCR £27.3 Scheme would be Planning permission required Avon Mill Lane fit progressed by BANES 2C – Pixash to Moderate/High Medium BCR £50.1 Scheme would be Planning permission required new junction on fit progressed by Could be objections from the A4175 BANES EA 3A – A4 new Moderate/High High BCR £23.9 Scheme would be Planning permission required junction to Avon fit progressed by Mill Lane Direct access BANES to SDL 3C – A4 new Moderate/High Medium BCR £46.6 Scheme would be Planning permission required junction to new fit progressed by Could be objections from the junction on Direct access BANES EA. A4175 to SDL Table 8.18: Summary of how the scheme options meet the five cases

The assessment shows that the key differences between the options relate to cost, ability to provide a direct access to the SDL and the impact to the natural environment, particularly impact to the risk of flooding.

9 Conclusions

Following examination of the 'short-list' options, it is considered that Option 3A is overall the best performing option and should be taken forward for further detailed consideration in the Strategic Outline Business Case (SOBC). This has a high BCR and provides a direct access to the proposed North Keynsham SDL. The benefit derived from Option 3A will depend on what is done at the A4175/Avon Mill Lane junction. However, a roundabout solution is shown to be feasible which will cater for existing ‘committed’ growth in the Keynsham Core Strategy whilst allowing for growth beyond this. The stopping up of Pixash Lane to vehicular traffic at the GWML bridge will enable this to be used by NMUs, promoting walking and cycling in the area. Furthermore, retention of northbound vehicular access through the existing Broadmead Lane under-bridge to an interim junction on the route will afford convenient access for residents in East Keynsham. Option 2A has a similar cost to Option 3A and also has a high BCR, but is not as well placed to serve the SDL. Options 2C and 3C involve a new bridge crossing over the River Avon, with a significant proportion of the highway alignment passing through Flood Zones 2 and 3. As such, these options may not be acceptable to the Environment Agency as they cross the Broadmead floodplain. Costs for Options 2C and 3C are also significantly higher than Options 2A and 3A. This is mostly due to the longer alignment and additional bridge structure, but also due to the additional design mitigation needed in the floodplain to reduce flood compensation and obstruction to flow path in an area with a history of flooding.

Appendix A - Constraints Plans

Appendix B - ‘Long List’ Highway Option Alignment Drawings

Appendix C - Geology and Ground Conditions: Desk Study

Appendix D - Environmental Report

Appendix E - FRA/Drainage Report: Stage 1

Appendix F - Services Drawings

Appendix G - Structures Assessment

Appendix H – Long List Option Sifting Tables

Appendix I - Option Design and Engineering

Appendix J - Traffic Modelling

Appendix K - Cost Estimates and Economic Assessment