Preferred Options Report Scheme Assessment Report 2
2 Existing Conditions
2.1 Sources of Information 2.1.1 Drainage and Hydrology The information used to compile this section and the associated drawings referenced within Volume 2 was sourced from the following:
• Consultations with key statutory bodies including Rivers Agency, Roads Service Maintenance Section Offices, Northern Ireland Water (NI Water), Loughs Agency and Londonderry Port and Harbour Commissionaires.
• Field work assessments of watercourses, floodplains and drainage catchments.
• Collation of historical flooding data.
• Fluvial design flow estimations based on Flood Estimation Handbook (FEH) Software.
• Existing Flood Risk Assessments and consultations with Rivers Agency Consultants.
• Preliminary hydraulic models (currently being refined).
Potential flood extent adjacent to river corridors is further delineated using information provided by the Mouchel Geotechnical Team. Alluvium drift geology mapping indicates the possible extent of floodplains arising from long-term historical flooding. It is noted that this data does not represent flooding associated with hydraulic restrictions such as culverts, bridges and retaining walls.
The NI Water infrastructure discussed in paragraphs 2.2.3, 2.3.3 and 2.4.3 includes drainage outfalls at numerous locations along the length of the Preferred Corridor. Discharge to watercourses from existing NI Water infrastructure is not considered further in the current section. The hydrology and drainage engineering review assumes that NI Water infrastructure will not be utilised/incorporated into the proposed drainage solutions for the A5 WTC.
In considering the existing drainage and hydrological conditions within the Preferred Corridor, desk based assessments have been supplemented with site visits and watercourse inspections. The desk based assessment utilised the information sources outlined in the previous section, with specific inputs/methodologies outlined below.
2.1.1.1 Primary Rivers Agency Data There are a number of discrete Units within Rivers Agency, each providing specific information that has been utilised in the current study.
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Rivers Agency GIS Unit have provided:
• River Centre Line Data
• Designated Watercourses
• Areas of Historical Flooding
• Rivers Agency Flood Defences
• Location of Rivers Agency HEC-RAS Models
• Rivers Agency Lidar Coverage Data
• NI Strategic Flood Maps
In addition, the Planning Advisory Unit have provided assessment guidelines and existing HEC-RAS models for the following watercourses:
• Ballygawley Water
• Burn Dennet
• Fairywater
• River Finn
• River Mourne
• Quiggery Water
• River Strule
Rivers Agency information relating to historical flooding has been reviewed and it is noted that the data set is incomplete, in particular between Newtownstewart and Strabane. The information has been digitised by Rivers Agency from aerial photographs depicting actual flood event, it is noted that there is considerable uncertainty in the return periods associated with individual flood events.
The Rivers Agency strategic flood maps were also made available to the public in November 2008. These maps have been consulted as part of this assessment and depict the extent of the predicted 1 in 100 year and the 1 in 100 year plus climate floodplains.
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Historical flood data for Londonderry, Strabane, Omagh and surrounding areas was also gathered from newspaper archives and microfiche held in Londonderry, Strabane and Omagh public libraries. Internet research was also undertaken.
2.1.1.2 Flood Risk Assessment & Previous Flooding Incidences Previous studies that have been reviewed include the River Finn Flood Study (N14/N13 Junction) - Mott MacDonald (Report and ISIS Model), Harcourt Development (Strabane) flood risk assessment report, available through the DoE Planning Service and Newtownstewart by-pass flood risk assessment report.
Consultations have been held with Roads Service Maintenance Section Engineers to collate data relating to the existing A5 and flooding. Reports relating to other roads projects previously undertaken within the study area have also been provided by Roads Service. These include Omagh Throughpass and Strabane Bypass Phase 3 (which has been subsumed into this scheme).
2.1.1.3 Tidal Data The northern extents of the A5 WTC study area include the River Foyle north of Strabane which flows into Lough Foyle. Lough Foyle is tidal and exerts a tidal influence on the River Foyle as far inland as the Rivers Mourne and Finn. Consequently, consideration of the tidal influence on these rivers adjacent to Strabane has been undertaken. Londonderry Port and Harbour Commissionaires were consulted in relation to tidal records for Lough Foyle.
The Admiralty tidal statistics for Derry Port and Lisahally Port were reviewed, together with a port location plan (refer to Figure 2-1 below).
River Foyle (Lisahally) Standard Harmonic Port
Londonderry Secondary Harmonic Port
Figure 2-1: Derry Port Location Plan
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To facilitate an understanding of the tidal effects on the Foyle River, tidal gauging was undertaken at 2 locations along the Foyle system between 28/08/08 and 05/09/08. The purpose of these gauges, in conjunction with the permanent tidal gauge at Derry (sited over a spring tide) was to gain an appreciation of the deformity of the tide as it progressed up the fluvial system.
2.1.1.4 Site/Watercourse Inspections The watercourses along the route of the existing A5 were identified, marked in GIS and mapped for site survey. Rivers Agency data was cross referenced with the FEH database and ordnance survey mapping. An additional 594 watercourse surveys have also been undertaken within the Preferred Corridor of the A5 WTC with information pertaining to watercourse shape, size and gradient collated. Typical site survey information is presented in Figure 2-2.
Figure 2-2: Sample from Site Survey Information Database 2.1.2 Existing Drainage The existing A5 highway drainage will continue to be a maintenance responsibility for Roads Service regardless of the alignment of the new road.
Through discussions with Roads Service Maintenance Section Offices and Rivers Agency, it is known that sections of the existing A5 have been prone to historical flooding. These areas are described in the relevant section paragraphs below.
2.1.3 Hydrology & Flooding Overview Preliminary hydrological reviews have ascertained the principal rivers and associated drainage basins within the A5 WTC study area. The main drainage basins are
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shown on drawing 796036-0500-D-00038. The principal watercourses are outlined in drawings 796036-0500-D 00011, 00014, 00017, 00020, 00023, 00026, 00029, 00032, 00035 in Volume 2. The watercourses to the north of Ballygawley feed into the main Foyle Basin which comprises the Strule River, Mourne River and River Foyle. The River Blackwater catchment to the south does not form part of the Foyle basin.
2.1.4 Structures Inspection Methodology Data on the structures on the existing A5 was gathered by desk study and on site inspections. This process comprised:
• A study of available client data, including inspection and maintenance records from the previous 5 years, the original construction records and “as built” drawings. It should be noted that all of this data was not available for every existing structure.
• A “walk through” survey which identified all the known bridges and located all the retaining walls and minor structures (less than 1.8m span) on the route.
• Detailed condition inspections of the major structures, using the HA BE/11 forms as well as the new draft HA “Performance Measurement of Highway Structures” (PMHS) system of inspection.
It should be noted that the inspections carried out were intended to produce condition survey results to inform decisions made regarding use of the existing structures on potential on-line sections of the proposed A5 scheme. Therefore, an inspection methodology was developed to ensure that significant defects were reported and recorded in such a way that issues which needed particular consideration during the design phase were readily apparent.
Consequently, the results do not necessarily align with the Roads Service condition survey reporting system as described in Roads Service Bridge Management System (RSBMS), which is aimed at informing a long term maintenance regime. Due to the need to assess the costs associated with the ‘Do Nothing’ option as well as the fact that all or some of the A5 may have been widened on line as part of the A5 WTC proposals, it was considered essential to identify the condition of the existing pavements along the route. The maintenance costs associated with the option of retaining the existing A5 as an A class road (i.e. the Do Nothing option) will be incorporated into Stage 3 Traffic & Economics work. It is also the case that the existing A5 structures will continue to be a maintenance responsibility for Roads Service regardless of the alignment of the new road
2.1.5 Pavements Due to the need to assess the costs associated with the ‘Do Nothing’ option as well as the fact that all or some of the A5 may have been widened on line as part of the
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A5 WTC proposals, it was considered essential to identify the condition of the existing pavements along the route. The maintenance costs associated with the option of retaining the existing A5 as an A class road (i.e. the Do Nothing option) will be incorporated into Stage 3 Traffic & Economics work. It is also the case that the existing A5 carriageway will continue to be a maintenance responsibility for Roads Service regardless of the alignment of the new road.
This summary deals with the assessment of the condition of the existing pavement. This assessment did not take into account the existing or predicted traffic flows and no construction records or previous maintenance works were made available in the compilation of this report. Therefore, no relationship between the structural properties and traffic loading can be established and no evaluation of the structural adequacy of the route can be considered.
To assess the structural condition of the pavement, various technical assessments were carried out along the 3 sections of the existing A5. The sources of data for these assessments included historical Deflectograph and SCRIM records, a newly commissioned Ground Penetrating Radar (GPR) survey and a visual assessment using a newly commissioned Digital Video (DV) survey. In summary, the visual and machine based surveys showed that the existing route is variable in its condition. There are some sections that have been improved and upgraded to current standards and are in good condition with a high residual value. Some older sections have more general deterioration with some defects requiring maintenance.
2.1.5.1 Deflectograph Deflectograph survey data dated 2002, 2004, 2005 and 2007 was provided by Roads Service. The data provided was then used to calculate the remaining life of the existing A5 pavement. The remaining life of the pavement was divided into 3 categories:
• Less than 5 years,
• Between 5 and 20 years,
• Greater or equal to 20 years.
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2.1.5.2 Visual Assessment using Digital Video Survey
Figure 2-3: Visual Assessment using Digital Video Survey A Traffic Speed Digital Video (DV) survey was carried out between 10 and 14 March 2008. A desk based visual assessment of the carriageway was then undertaken using data obtained from the DV survey by analysing the video and abstracting the visual signs of physical deterioration. The extents of any defects were identified from their start chainage to end chainage and then rated according to the proportion of the lane width they covered; the severity of the defects has not been assessed. Figure 2-3 above shows a snap shot of the digital video survey.
2.1.6 Traffic and Economics Paragraphs 2.2.9, 2.3.9 and 2.4.9 of this report describes the existing conditions of traffic and accidents along the A5 WTC Preferred Corridor. As the proposed A5 WTC has been divided into 3 sections for highway design purposes, the existing conditions are reported below for these 3 sections, together with overall corridor summaries.
Traffic data has mainly been taken from the traffic surveys commissioned specifically for the A5 WTC scheme in spring 2008. These included Road Side Interviews, Manual Classified Counts, Automatic Traffic Counts and Automatic Number Plate Recognition surveys as well as use of existing survey information.
Traffic surveys are generally undertaken in neutral months in order to minimise the variability of traffic flows. For the A5, the majority of data was collected in the neutral month of May 2008. As a consequence this month has been specified as the base for the subsequently developed traffic model. It should be noted that there were no
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school holidays during May 2008 in Northern Ireland so the different characteristics of traffic during school holidays are therefore avoided.
Data from the surveys commissioned for the A5 scheme have been used in assessing the existing traffic conditions in the corridor and have been presented below in terms of traffic flows, turning movements, vehicle proportions, tidality, daily flow profiles, vehicle speeds and summaries of origins and destinations of traffic.
In addition to the short term surveys commissioned for the A5 scheme itself, use was also made of longer term automatic traffic count data at NIRS sites to assess seasonal variation of traffic flows.
Accident data analysis requires longer term data for meaningful analysis (generally 3 to 5 years). Consequently, data was not collected specifically for this scheme and use has been made of the Personal Injury Accident information collated by the PSNI Statistics Division along the route corridor for years 2003-2006 inclusive. At the time of writing, 2007 data had been released in draft. However, as this is still potentially subject to change accident data from 2007 has not been included in the analysis of accident rates. Corridor accident rates have also been compared with regional or national average rates, as appropriate.
2.1.7 Existing Accident Conditions 2.1.7.1 Introduction An analysis of accidents occurring on the A5 WTC and its key side roads was carried out.
Accident records are an essential element of a scheme’s economic appraisal using the Cost Benefit Analysis (COBA) program (DMRB, Volume 13). COBA is currently the only Department for Transport program able to calculate economic benefits from accident savings. COBA makes forecasts of accident numbers and severity and the resulting accident costs across a network over 60 years.
The COBA program includes a set of average accident rates for different road types. These are expressed in terms of the number of Personal Injury Accidents (PIA) per million vehicle kilometres. Two rates have been calculated for roads which represent either ‘Combined Links and Junctions’ or ‘Link-Only’.
COBA also forecasts the number of PIAs at junctions. A further definition of these 3 accident rates can be found in Table 2-1 below. Personal Injury Accidents (PIAs) are categorized as fatal, serious or slight depending upon the severity of the worst casualty in each accident. As part of the analyses described in the report, fatal and serious accidents have been summed together and shown as a proportion of all PIAs (F+S/PIA ratio) i.e. the ratio of "fatal + serious" to "fatal + serious + slight" accidents on any given link or junction. For example if there were 10 PIAs on a link and 2 were fatal, 3 were serious and 5 were slight, the .F+S/PIA ratio would be 0.5 [(2+3)/10].
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Table 2-1: Explanation of types of COBA accident forecast Forecast Type Definition Determinants Units Personal Injury Rates attribute all accidents to Accidents per Combined Link the links. As such, 'Combined ▪ Road type million vehicle and Junction Link and Junction' rates are ▪ Speed over or under 40 mph kilometres greater than those for 'Link Only.' (PIA/MVKm)
Personal Injury Rates exclude accidents Accidents per ▪ Road type Link Only occuring within 20 metres of million vehicle ▪ Speed over or under 40 mph junction. kilometres (PIA/MVKm)
Forecasts the number and ▪ Junction type Number of severity proportions of accidents ▪ Number of arms Junction Personal Injury occuring within 20 metres of a ▪ Flow on major/minor links Accidents per year junction. ▪ Speed limit (threshold at 40mph)
COBA average accident rates are based on data collected from England, Scotland and Wales between 1999 and 2001. COBA also includes data on accident severity and categorises accidents as fatal, serious or slight, depending on the most serious casualty involved (as described below).
Accident rates (and severities) have generally been decreasing over time, and COBA uses a change coefficient to reduce the annual accident rates during the economic appraisal period.
COBA average PIA rates and severity proportions can be identified using the determinants listed in Table 2-1.
Comparison between observed accidents and average COBA values The observed accident rates on the existing A5 road have been compared with COBA average values in order to identify any noticeable trends. The results are shown in Tables B-9 to B-11, B-19 to B-21 and B-29 to B-31 within Appendix B.
Main line (A5) links and key side roads have been compared with COBA ‘Link-Only’ and ‘Combined Link and Junction’ accident rates and severity proportions separately. To simplify the comparison, COBA accident rates for the base year (2000) have been used, with no attempt to correct these for the period 2003-2006. Such a correction would have had minimal effect on the rates.
Strategic junctions along the A5 have also been compared with COBA junction accident rates. To do this, COBA requires Average Annual Daily Traffic (AADT) flow values on each arm of the junction in order to calculate the number of accidents. Traffic flow data on the A5 arms was taken from Road Service’s Traffic & Travel Information Reports 2003-2006. This did not cover all side road arms. Mouchel commissioned turning counts at each of the strategic junctions in April 2008. The A5 flows at each junction from both sources were compared to derive conversion factors
796036/0000/R/011 Version 2 20 ©Mouchel 2009 Preferred Options Report Scheme Assessment Report 2 for flows from 2008 to the 2003-2006 period. These factors were then applied at each junction to derive 2003-2006 AADTs at non-A5 arms.
There have been some ‘junction accidents’ which have occurred on ‘non-strategic junctions’. These are reported in the ‘combined link and junction’ totals but not in the ‘link-only’ nor in the data for key ‘strategic junction’. Consequently link accident numbers plus strategic junction accident numbers do not sum to the total ‘combined link and junction’ accidents.
The COBA program calculates the number of PIAs at junctions per year. These calculations are based on AADT which the program increases annually to reflect projected traffic growth. However to simplify this analysis, calculations have been carried out using (average) 2003-2006 AADT flows only. The annual accident values have been multiplied by 4 to compare with the total PIAs in the 4-year period at each junction to be assessed.
Accident Severities The accident data includes information on accident severity. The severity of an accident is defined by the most severe casualty sustained as a result of the accident. The 3 casualty severity levels are defined in Table 2-2.
Table 2-2: Definition of casualty severity levels Severity Defintion Fatal Death within 30 days as a result of the accident Serious Fracture; Severe cuts; burns; concussion; detention in hospital as an in-patient Slight Strains; whiplash; bruises; slight cuts; slight shock
The COBA program also calculates the number and type of casualties for each link and junction. The COBA manual reports the national average proportions of each accident severity for the various types of link or junction, based on data collected between 1999 and 2001.
As part of the analyses described in this report, fatal and serious accidents have been summed together and shown as a proportion of all PIAs (F+S/PIA ratio). Individual F+S/PIA ratios have been calculated for each type of link or junction as described by COBA. Default COBA severity ratios and accident rates are determined by the link or junction type as well as the maximum speed on the links or at the junctions. Table B-1 within Appendix B describes the link and junction types analysed in this report, as well as their default COBA F+S/PIA ratio.
Observed accidents between 2003 and 2006 are reported by severity. An F+S/PIA ratio has then been calculated by dividing the sum of observed fatal and serious accidents by the total observed PIA accidents on the link or at the junction.
A comparison of expected (national average) and observed F+S/PIA ratios gives an overview of how the severity of the accidents on links and junctions between 2003 and 2006 compare with the national average. The values can then be considered alongside accident rates; a low accident rate and high F+S/PIA ratio compared to
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COBA default values could still involve fewer than expected fatal and serious accidents than COBA would estimate based on national rates.
The Three A5 WTC Sections As mentioned previously the length of the A5 WTC is divided into 3 sections. Figures 2-4, 2-19 and 2-33 show the boundaries of each section, which can be described as follows:
• Section 1; from New Buildings to South of Strabane (Sion Mills)
• Section 2; from South of Strabane (Sion Mills) to South of Omagh
• Section 3; from South of Omagh to Aughnacloy
Main line links, key side roads and junctions have been divided among the 3 sections and are shown on figures 2-4, 2-19 and 2-33. Appendix B Tables B-9 to B-11, B-19 to B-21 and B-29 to B-31 with the section text summarise the comparative ‘Link- Only,’ ‘Combined Link and Junction’ and “Junction” accident statistics along the A5 corridor for each section.
2.2 Existing Conditions – Section 1 New Buildings to South of Strabane 2.2.1 Description of Current Network The chainages referred to in this chapter are taken from the existing assessment drawings, which for Section 1 are numbered 796036-0800-D-00001 to 796036-0800- D-00018, and are included in Volume 2 for reference.
The existing A5 within Section 1 runs for approximately 21km south from New Buildings towards Strabane, initially travelling adjacent to the River Foyle. It passes through Magheramason before continuing in a south-westerly direction round the base of Gortmonly Hill toward the bridge over the Burn Dennet River. After the river crossing, the A5 continues to traverse between sparsely located residential and commercial properties, while passing through villages and hamlets (Cloghcor and Ballymagorry). The A5 then enters Strabane utilising an at-grade roundabout junction with connections to Lifford Road (A38) and Railway Street (B73), before crossing the River Mourne. After the river crossing, the A5 enters a roundabout with Bradley Way, before heading onto the Strabane bypass round the western edge of the town. The A5 then joins Melmount Road at another roundabout at the end of the bypass, before heading south to Sion Mills.
There are natural and man-made constraints along the existing A5 which obstruct upgrading possibilities. The man made constraints include:
• Golf course south of Londonderry (Ch.3100 – 3750),
• St. Mary’s Oratory and Primary School in New Buildings (Ch.4300 – 4750),
• A textile factory south of New Buildings (Ch.5050 – 5200),
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• Magheramason Presbyterian Church (Ch.7500),
• Bready Reformed Presbyterian Church (Ch.10500),
• St John’s Church in Bready (Ch.11050),
• Burn Dennet Bridge (Ch.13900),
• Spruce Road Bridge (Ch.19700),
• Ballymagorry Bridge (Ch.17225),
• River Mourne Bridge (Ch.21900).
There are also a number of settlements comprising commercial properties such as shops, filling stations, public houses and housing throughout the stretch of the existing A5 from New Buildings to Strabane.
The settlements in Section 1 fall within either The Derry Area Plan 2011 or the Strabane Area Plan 1986-2001. As in most developments, housing, industry, commerce, community facilities and recreation/open space are situated at convenient locations in the community. Various cultural, landscape and environmental features also dot the surrounding areas of the A5, such as Rivers Finn and Foyle to the west (and associated floodplain), Knockavoe Hill and the West Sperrin Mountains to the east (including the Sperrins Area of Outstanding Natural Beauty). Major planning applications in this region in the last 8 years include a new cricket and sports pitch at Magheramason (approval in 2006 under construction during option appraisal), restoration of the Strabane Canal between the River Foyle and Glenmornan River (approval in 2006 under construction during option appraisal ), and a proposed strategic mixed use development to the west of Strabane (employment park, a leisure complex, and hotel) along the River Foyle immediately west of the existing A5 (status pending).
The main economic activity in the region is agriculture. There are expansive areas of Best and Most Versatile lands; private and Department of Agriculture and Rural Development (DARD) Woodlands, and agri-environmental schemes. The whole of the River Foyle and its tributaries are well known in Northern Ireland for game and coarse fishing, supporting a diverse mixture of fish and river dynamics. Major tributaries known to be used extensively by anglers consist of the Burn Dennet (originating in the West Sperrins and running west towards Cloghcor) and the River Mourne (running north from Newtownstewart to Strabane). Two Public Angling Estates (Moor Lough and Lough Ash) are also located in the Sperrins east of Strabane.
Public transport is run by Translink Bus services in this area are fairly limited, with the only rail connection to the west being the Belfast-Coleraine-Londonderry line. The bus routes in this corridor consist of the Ulsterbus services 102 between Strabane and New Buildings; service 101 between Sion Mills and Strabane; route 98 between Strabane, Ballymagorry and New Buildings; Strabane town services 398A-D and
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Goldline Express service 273. The routes run infrequently, providing hourly services at best. Smaller settlements such as Magheramason, Bready and Cloghcor do not have access to mainstream public transport, although there are private bus companies such as Chambers which offer, among other services, door to door minibus services aimed at elderly and less mobile customers all over the country.
Sustrans are responsible for the National Cycle Network, which in this region, can be found going out of New Buildings along the B48, and through Strabane, exiting the town on the B72.
A number of A and B Class routes join the existing A5 within the extent of Section 1. The routes are identified in Table 2-3, along with the local settlement with which they connect.
Table 2-3: Section 1 A and B Class routes join the existing A5
Route Chainage on existing A5 Connecting town
B48 4,650m New Buildings
B49 17,700m Ballymagorry/Strabane
B72 21,750m Strabane
A38 21,750m Strabane/Lifford
B85 22,700m Strabane
An overview of Section 1 showing the Preferred Corridor, Development Limits and intersecting route/links are shown in Figure 2-4 below.
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Figure 2-4: Overview of Section 1: Preferred Corridor, Development Limits and Intersecting Routes/Links within Section 1
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2.2.2 Existing Highway Conditions The majority of the existing A5 from New Buildings to the south of Strabane is derestricted, and is therefore subject to the national speed limit of 60mph. In accordance with the Design Manual for Roads and Bridges (DMRB) TD9/93, this equates to a design speed of 100kph. A geometric assessment of the stopping sight distance, the horizontal and vertical alignments has been carried out. The full overtaking sight distance assessment has also been carried out for the existing carriageway. This gives a safe distance for overtaking on single carriageways, and is generally only realistically achieved in areas of relatively flat terrain. The geometric assessment of the existing A5 was carried out using the existing speed limits and is graphically presented in drawings 796038-0800-D-00001 to 796038-0800-D-00018 in Volume 2 and Appendix A. The drawings note the variances in speed limit. As shown on these drawings, there are 51 areas that are sub-standard to such an extent that they would require departures from the current standard TD9/93 (DMRB 6.1.1).
Section 1 of the A5 is approximately 21km in length and runs south from New Buildings towards Strabane, initially travelling adjacent to the River Foyle. With over 300 residential, farm and commercial accesses directly onto the road, the A5 is classified as a high density access constraint, which has an impact on both traffic speed and safety. The A5 is generally undulating and lies at the foot of several hills: the highest point is 37m AOD between Meenagh Road and Ballybeeny Road (south of Magheramason) and the lowest point of the road is 3.5m AOD between A5 Barnhill Road and Park Road (Strabane). Footways and kerbing are generally provided all through the settlements.
The cross-section widths of the carriageway vary throughout, between 6.3m and B.7m, and on occasion, do not meet the current standard requirements either in terms of road or verge widths, or by the absence of a hard strip. These discrepancies generally occur between population settlements, with the exception of the road running through Bready. The northbound carriageway through Bready also contains a 115m-stretch which does not comply with stopping sight distance standards.
The road is generally undulating on the approach to Magheramason, and passes through the town, widening from 7.5m into a 10m-wide, 775m-long southbound climbing lane (Figure 2-5). It then narrows back down to 6.5m and continues in a south-westerly direction round the base of Gortmonly Hill, toward the bridge over the Burn Dennet River. The minor roads joining this section of the trunk road primarily weave between farms and have no road markings except at their intersections with the A5 and their average cross-section width is 2.8m.
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Figure 2-5: Transition to climbing lane, Magheramason Mason Road, Dunnalong Road, and Drumenny Road, with 30mph speed limits, are wider at 6m with kerbs, footways and vehicle lay-bys, and run through residential/commercial areas. Approximately 500m south of the Burn Dennet River crossing, the level of the road drops to 4.1m AOD; furthermore, the A5 narrows to 6.3m-wide to a point immediately north of Cloghcor, where it is widens to 7.6m, rising to 10.7m AOD, and continues to traverse between sparsely located residential and commercial properties. Victoria Road (A5) widens to 13.4m between Cloghcor and Leckpatrick to accommodate a 750m-long northbound climbing lane. South of Leckpatrick Victoria Road (A5) continues southwards as it passes through a number of smaller communities and over the Glenmornan River.
South of the Glenmornan Rover Victoria Road (A5) widens to 8.4m to include a dedicated right-turning lane for northbound traffic into Woodend Road in Ballymagorry. The road is generally undulating in this section, reducing to a width of 7.3m which is maintained as Victoria Road enters Strabane. Most of the minor roads along this stretch are predominantly urban with kerbs, footways, vehicle lay-bys and a speed limit ranging between 30 and 60mph.
Figure 2-6: Signalised pedestrian crossing at River Mourne crossing
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The A5 enters Strabane as Derry Road to a point 650m south of Woodend Road in Roundhill (north Strabane), where the road widens from 7.3m to approximately 9.6m to facilitate provision a right-hand turn lane. Immediately prior to the widening, Derry Road (A5) becomes Barnhill Road (A5). The road level is approximately 3.5m AOD with little vertical deviation. South of this point Barnhill Road (A5) joins a roundabout with Lifford Road (A38). At the roundabout, the road widens to 3 lanes with a dedicated left turn onto Railway Street.
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Figure 2-7: Combined footway and cycleway on either side of the A5 at Strabane Bypass South of the bridge over the River Mourne, Bradley Way joins a roundabout and branches off as one arm while the A5 continues as the Great Northern Link, 9.3m wide, inclusive of 1m hard strips. An approximately 3m-wide combined footway and cycleway (Figure 2-7) can be found on either side of the road, south of the intersection with Urney Road. The Great Northern Link then heads onto the Strabane bypass round the western edge of the town, joins Melmount Road (A5) at another roundabout at the southern end of the bypass, is narrowed down to 6.4m wide, and then heads south towards Sion Mills. The road level rises steadily from 7m AOD south of the river crossing, to 33m AOD prior to joining this roundabout. Most of the minor roads in Strabane pass through residential and commercial areas while some run through farmlands. The speed limit of the minor roads range between 30 and 60mph and the average cross-section width is 3.4m. There are road markings, kerbs, footways and vehicle lay-bys along the length of some of these roads.
2.2.3 Utilities Electricity, potable water, foul water and various telecommunications are the main services located within the Preferred Corridor. These services are concentrated in, and around, settlement areas, however, transmission lines and trunk mains also traverse the rural areas of the scheme corridor. The existing A5 provides the main utility corridor in the vicinity of the proposed scheme. Details of the major ultilities plant can be found in drawings 796036-0100-D-10001 and 10002 in Volume 2.
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2.2.3.1 Electricity Northern Ireland Electricity (NIE) have a network of 110kV and 33kV overhead transmission lines, which radiate from a sub-station just south of Ballymagorry. From this substation, a 33kV cable follows the line of the existing A5, north to New Buildings, with a further two 33kV lines running west from Ballymagorry skirting the western edge of the Preferred Corridor, one supplying Strabane with the other continuing southwards to Sion Mills.
Two 110kV lines, one mounted on pylon structures and the other on poles, run parallel to each other from the eastern side of Londonderry and continue south passing to the east of the scheme corridor. These high voltage lines then converge, entering the Preferred Corridor due north of Strabane, and connect to the Ballymagorry sub-station before continuing southwards to the east of Sion Mills.
NIE have networks of medium and low voltage distribution cables within settlement areas.
2.2.3.2 Water mains and Sewers These assets are owned by Northern Ireland Water (NI Water) Limited.
The network of NI Water utilities within the Preferred Corridor is widespread and the proposed scheme will likely result in the requirement for remedial works to these services, regardless of which option is chosen.
A water main, diameter 100mm – 300mm, runs along the existing A5 for the entire length of Section 1. A larger water main, diameter within range 300mm – 450mm, runs from the south of Ballymagorry to the east of Strabane and continues in Section 2.
Most of the NI Water sewer network is limited to urban areas, with the foul waste generated by isolated rural properties being discharged into septic tanks. With regard to major utilities, a 300mm – 600mm diameter sewer runs along the existing A5 from Londonderry to New Buildings.
2.2.3.3 Telecommunications The existing A5 provides the main utility corridor, for telecommunications apparatus, within this section of the scheme. Several providers share a common trench within the A5, from Londonderry to Magheramason, which contains fibre optic cables. The 4-way duct housed within this trench is populated with services owned by Virgin Media, Eircom and Bytel networks. From Magheramason, these cables branch off the A5, to the east, then divert south running parallel to the A5 before rejoining it via Artigarvan and Ballymagorry. These services then continue from Ballymagorry to Sion Mills at the southern end of Section 1.
British Telecom (BT) have a network of underground and overhead services located within the Preferred Corridor, with a significant route again running along the existing A5 over the full extent of Section 1, with branches out of Strabane along the A38
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Lifford Road, the B85 Urney Road, the B72 Liskey Road and the B536 Fountain Street in a south-easterly direction.
Based on current information, 10 mobile phone base stations/masts are sporadically located, within the Preferred Corridor, throughout this section.
2.2.3.4 Miscellaneous Current utility information indicates that there are no gas pipes or wind farms located within Section 1.
2.2.4 Geotechnical The ground conditions in Section 1 of the scheme break easily into 2 zones which are defined by the underlying geology, with the high and steep ground of the Sperrin Mountain Foothills in the east and the soft ground of the Foyle, Mourne, Finn, Burn Dennet and Glenmornan Floodplains in the west. Drawings of the ground conditions for Section 1 are split into the following three categories and can be found in Volume 2.
• Digital Terrain Model/ Drift Geology on drawings 796036-0600-D-10001 & 10002
• Slope Gradient/ Potential Contaminated Land/ Quarry Exents on drawings 796036-0600-D-10003 & 10004, and;
• Solid Geology on drawings 796036-0600-D-10005 & 10006.
2.2.4.1 Topography The Foyle floodplain dominates the west of this section, between Bready and Strabane. This is generally a broad floodplain (500-1000m) narrowing north of Bready where high ground slopes directly down to the river bank. The meandering broad valley of the Burn Dennet extends in an east west direction towards the River Foyle in the far south of the section, between Milltown Burndennet and Cloghcor. The River Foyle terminates at Strabane at the confluence of the Rivers Finn, Mourne and Foyle. The floodplain of the Foyle, and to a lesser degree the Mourne through Strabane, is wide and extensive. The floodplain of the Finn is relatively narrower on the Tyrone bank.
To the north-east of Section 1 the main areas of high ground are Clondermont, Gortmonly and Slievekirk all with characteristic steep sided slopes typically 1(v):5(h)- 1(v):2(h). Clondermont falls, steeply on its western slopes to the Foyle shoreline north of New Buildings, whilst the western extent of Gortmonly is skirted by the existing A5. Slievekirk and Gortmonly are separated by the steep sided north-south aligned Burngibbagh Valley whilst further south the broad valley associated with the east-west flowing Burn Dennet and Glenmornan River extends. Two areas of lowland peat bogs are located west of Cloghcor and Leckpatrick.
The Sperrins encroach to the east between Strabane and Cloghcor in the form of several well rounded flat topped outlying summits - Windyhill (150m AOD), Sentry Hill and Six Penny Hill which have steep lower slopes of 1:5-1:3. The lower slopes of
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Knockavoe also rise to the south east of this area, as steeply as 1:2. In general though, the hills are lower than those further north and are bisected by the broad valley associated with the east-west flowing Burn Dennet and Glenmornan River. At Strabane the east is very constrained by the high ground and urban development on the edge of the town. The ground rises very steeply up to 1:10-1:3 into the foothills of the Sperrin range in the form of Knockavoe (295m AOD) and Carrigullion (240m AOD), which sprawl to the eastern edge of Strabane. Strabane and Pattens Glens on the eastern limits of the Strabane development area have localised steep slopes (1:5-1:2). The deep and sheer sided Strabane Glen follows a north/south alignment, and may be a geological fault line or a mineral vein which has been re-worked. This has been designated an Area of Special Scientific Interest (ASSI) on account of vegetation and woodland present. Pattens Glen is a gorge orientated in an east-west direction.
2.2.4.2 Solid Geology Section 1 of the scheme is underlain by Precambrian Strata (Dalradian in age) which form a large fold known as the Sperrin Nappe. The northwest of the Sperrin Nappe, pertaining to this area, consists of the main stratigraphic units; Ballykelly, Claudy and Dungiven Formations which are separated from the extreme northwest, by the Pettigoe Fault which takes the approximate line of the Foyle Valley.
In the north of Section 1 the rocks are generally a mix of old hard shale1, schist2 (pelite3) and sandstone (Psammite4). In the vicinity of New Buildings the strata in the underlying solid strata have been identified to be the Ballykelly Formation, made up of a coarse grained meta-arenite with psammites and pelites. This formation is likely to be close to the surface around Clondermont Hill.
The remainder of the section is predominantly underlain by the Claudy Formation, also of the Southern Highland Group and made up of mixed psammite and semi- pelites interbedded with bluish grey medium to coarse grained meta-limestone, with the Pettigoe Fault continuing west throughout the region. These are exposed in a small disused quarry near Bready and the weathered surface appears to be friable schist.
A mosaic of drift free summits associated with the Sperrin range is shown to have bedrock at or close to the surface in the vicinity of Bready. Local Pre-Caledonian unnamed igneous intrusions consisting of Metamorphosed Basaltic Rock appear to underlay the drift around Magheramason.
The area just south of Artigarvan is underlain by the lithologically diverse Dungiven Formation of the Argyll Group. This encompasses pelite, semi-pelites, psammite and quartzite with limestone as the major constituent.
1 Shale = metamorphosed mudstone with a defined parting 2 Schist = fine grained metamorphic rock with strongly defined, though often irregular parting 3 Pelite = metamorphosed and hardened mudstone 4 Psammite = metamorphosed & hardened sandstone/gritstone
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In the areas immediately east and south of Strabane, the older Dungiven Formation is exposed, which contains a higher proportion of metamorphosed limestone than further north, also with local Pre-Caledonian un-named igneous intrusions consisting of Basaltic Rock around Flushtown.
2.2.4.3 Drift Geology Drift is largely absent on the high ground and around Bready & Cullion.
The majority of the overlying material in the north of the area, as well as south of Strabane is Glacial Till5 with deposits of dense sand and gravel concentrated around the south of the section.
The dominant drift soils are alluvium consisting of predominantly soft grey clay/silt overlying thick sand & gravel, associated with the River Foyle floodplain, extending up to 1km wide and potentially to a significant depth at the southern extents of the section. In regions of low-lying ground these are overlain with Peat deposits where ground water is close or at the surface. Two areas of lowland raised peat bog are locally present west of Leckpatrick and Cloghcor
Alluvial deposits associated with the Burn Dennet River also form an irregular plain surrounded by dense glacial outwash sands and gravels with extensive cobbles and boulders. These deposits are extensively extracted in this region.
A blanket Peat bog is noted on the summit of Knockavoe Hill at the eastern extents of the study area.
The occasional band of undifferentiated hummocky Glacial Moraine is indicated to have been deposited adjacent to the River Finn stretching from Westward in the north to Flushtown in the south and also in the vicinity of the Cavanalee Valley.
2.2.4.4 Man-made Features, Contaminated Land and Mineral and Mining Resources Man-made Features, Contaminated Land Potential areas of high risk contamination within the Preferred Corridor comprise the closed Bricklin Landfill to the north of New Buildings, which was previously a quarry. Various localised areas of fly tipping, in addition to a disused quarry are present, particularly in the vicinity of Magheramason and Sollus. A number of petrol stations are present, adjacent to the existing A5. Several disused corn and flax mills and kilns are located within the corridor but should present a low risk of contamination from ground contamination which may have occurred as a result of accidental spillage of chemicals in storage areas or during processing. The region of Ballymagorry is largely greenfield with the most significant contamination risk associated with industries around Artigarvan, which include a paper mill, petrol station and a dairy. Historical petrol stations occur across the whole area that may be local point sources of contamination in particular 2 adjacent to the A5 in
5 Glacial Till – deposits formed beneath glaciers or deposited by retreating glaciers, often dominated by clay (which can actually be pulverised rock-flour), but with a significant content of sand, gravel, cobbles and sometimes large boulders.
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Magheramason. The backfilled Strabane Canal extends along the west of the section adjacent to the River Foyle and a vehicle scrap yard can be found adjacent to this in the vicinity of Desert.
The Strabane area is probably the most likely in the whole Preferred Corridor to be affected by contaminated ground. Areas of potential contamination in the Strabane area are largely a function of the built environment. The section is dominated by Strabane town and the area by the old Strabane Canal, which encompass several historical land uses; dock yards, abattoir, tannery, ironworks and a gasworks site around the present A5/A38 junction. The canal itself is partially infilled with unknown material. Areas of fly tipping have been identified across this section, in particular to the south of Dublin Road Industrial Estate and around Gallany. In addition, 6 areas of known landfill are present;
• Three small areas adjacent to the sewage works north of Strabane.
• Underlying the existing A5 Strabane bypass, (previously a refuse tip).
• Adjacent to Urney road west of Carricklee Hill, historically a refuse tip but presently serves as a waste transfer site.
• Adjacent to Orchard Road Industrial Estate, previously a refuse tip.
Mineral and Mining Resources Active sand and gravel extraction is taking place in the vicinity of Lough Neas on the banks of the Burn Dennet. In addition, within the corridor, north of Ballymagorry there are a number of small disused quarries and gravel pits which may now have been backfilled (with unknown materials) or left as open scars in the landscape. In the Strabane area it should be noted that there are a large number (34) of disused quarries, especially in the limestone in the high ground to the north and east of Strabane, which may be backfilled and reclaimed with unknown materials or left as open scars in the landscape. A large disused flooded limestone quarry south of Strabane imposes a significant physical constraint on the landscape and 2 disused short metal mine adits have been identified adjacent to the River Mourne west of Milltown. Twelve disused sites of historical sand and gravel mineral extraction are also located within the area of Artigarvan/Ballymagorry, some of which may be backfilled and the land reclaimed in an unknown manner, or others which may be open scars in the landscape. No other mineral extraction sites within Section 1.
2.2.5 Drainage and Hydrology The existing drainage and hydrological features for Section 1 within the Preferred Corridor are described in this section. Specific engineering constraints are outlined in conjunction with information relating to flooding considerations.
Preliminary hydrological assessments have been made in order to ascertain the principal rivers and associated drainage basins within the A5 WTC Preferred Corridor. The main drainage basins are shown in Figure 2-8.
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Figure 2-8: Principal Drainage Basins
There are a number of watercourses flowing through Section 1 of the Preferred Corridor. In general, the principal watercourses flow from the south to the north, discharging to the River Foyle, which flows approximately parallel to the west of the existing A5, into Lough Foyle north of Londonderry. The main Foyle basin comprises the Mourne River and River Foyle. Lough Foyle is tidal and exerts a tidal influence up the River Foyle as far inland as the Mourne and Finn Rivers at Strabane.
Lough Foyle is subject to 2 high tides per lunar day and around 705 tides per year. It should be noted that published predicted tide levels do not take into account any meteorological effects. Such effects (wind and pressure) can significantly alter the observed tide, causing it to deviate considerably from the predicted values.
• Rivers Agency (Hydrometrics Unit) and Londonderry Port and Harbour Commissionaires were consulted in relation to actual tidal records for the Foyle. Rivers Agency (PAU) supplied extreme 200 year tidal levels. The 200 year tide level (including storm surge) for Milligan Point was 2.58m AOD. There were no 200 year levels available for Lough Foyle.
The principal tributaries to the River Foyle in the study area include the Rivers Finn and Mourne, which converge to the western side of Strabane town to form the River Foyle. The Glenmornan at Ballymagorry and the Burn Dennet also join the River Foyle system
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The Burndennet catchment is predominantly rural but does include the small urban catchment of Dunnamanagh, the river incorporates a number of principal tributaries, including the Cullion Burn, Mountcastle Drain and the Altinaghree Burn. In general, the river flows in an east to west direction from the highland areas of Mullaghclogher (635m AOD) and Slievekirk (370m AOD) to where it discharges to the River Foyle. The river is approximately 27km, from source to discharge, and flows perpendicular to the Preferred Corridor.
The Glenmornan watercourse is approximately 12km in length and flows from its source, in the Owenreagh Hill area to its point of discharge into the River Foyle at Cloghcor. The Glenmornan receives flow from numerous smaller streams and flows perpendicular to the Preferred Corridor. The catchment area of the watercourse is predominately rural but it does include the small urban catchments of Artigarvan and Ballymagorry.
Through discussions with Roads Service Maintenance Section Offices and Rivers Agency, it is known that sections of the existing A5 within Section 1 have been prone to historical flooding.
• South of Burndennet Bridge, north of the junction with Lough Neas Avenue – The road previously flooded in this region to a depth of 1.2-1.8m.
• Urney Road Roundabout, Strabane – flooding encroaches onto the road.
Alluvium drift geology mapping and Rivers Agency Strategic Floodplain Maps indicates potential floodplains at the following watercourses; the Blackstone Burn, the Bready Stream, the Gortmessan Drain, the Ballymagorry Burn and the Backfence Drain.
At the Burndennet Floodplain at Burndennet Bridge on the existing A5, the road previously flooded to a depth of 1.2-1.8m. Rivers Agency subsequently provided flood defences (clay embankment) in this area. Historic flooding records and alluvium mapping indicate that the existing floodplain is around 200m wide at the existing A5 crossing, increasing in width according to the various corridor locations.
The Glenmornan River Floodplain at Ballymagorry is potentially over 400m wide west of the existing A5. Flood defences, in the form of earthen embankments are sited along the route of the watercourse through Ballymagorry Town.
The floodplain at Strabane, where the Mourne and Finn Rivers converge with the River Foyle is potentially sensitive to flooding occurrences. Rivers Agency historic records indicate significant flooding in the area in 1987, albeit the flooding in Strabane Town Centre was as a result of the breaching of masonry defences and not overtopping. Subsequent to this event, new concrete flood defences were constructed in 1991. The existing A5 partially crosses some 3km of floodplain around the town.
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There are no existing flood defences on the Mourne River/Mourne-Strule Extension between Strabane and Sion Mills. Alluvium mapping and Rivers Agency Strategic Flood Maps indicate that there are some extensive floodplain areas parallel to the Mourne River/Mourne Strule Extension between Strabane and Sion Mills, with a maximum width of approximately 900m. There are no other significant watercourses or floodplains identified to the south of Strabane.
2.2.6 Existing Structures Conditions This section of the document deals with the assessment of the condition of the existing structures, recommendations on any remedial works required and comments on the options for widening each structure in Section 1. For those sections of the existing route where there are significant constraints to widening the route, such observations are made.
2.2.6.1 Summary of Route There are 8 significant structures in Section 1 having a span greater than 1.8m, although only one of them (Mourne Bridge) is considered to be a major crossing, having a cumulative span of 68m.
The majority of the bridges carry the existing A5 over watercourses with only 1 road over road bridge at Woodend. This is typical of routes in such landscapes where most junctions are at grade. Generally the structures are not very large with a median span of 10.2m but with a maximum span of 68.0m.Table 2-4:
Table 2-4: Bridges by Function and Section
Section Function 1
Footbridge Over Road - Road Over Accommodation 1 Road Over Pedestrian Subway - Road Over Road 1 Road Over Watercourse 6 Grand Total 8
As indicated in Table 2-4 above, there are a total of 8 significant bridges (i.e. > 1.8m span) on the route. There are no retaining walls over 1m high which either support the road or retain landscape and/or structures adjacent to the road.
2.2.6.2 Structure Types Of the significant bridges, there are a wide variety of construction types, with some of mixed construction where the structure has been widened.
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Table 2-5: Significant Structures by Road Section
Structure Type Section 1
Composite Concrete & Steel - Concrete Arch/Masonry Arch 1 Concrete Box Culvert 1 Corrugated Steel Pipe 1 Half Joints - Masonry Arch 2 Masonry Arch/RC Slab - Prestressed Concrete Beams 2 RC Pipe 1 RC Slab - RC Slab/RC Pipe - Steel Truss/Steel Plate - Grand Total 8
In addition, there are a number of small culverts (less than 1.8m) whose construction was often unclear as they were submerged or otherwise hidden.
No retaining walls (>1m high) were identified along the route where failure may impact on the efficacy of the carriageway.
Very few construction details were available for inspection for any of the major structures and none for the minor structures. An assessment of the basic construction type is included in the national database and this has been used as a basis for this study. For the minor structures and retaining walls, no attempt has been made to classify the construction type.
The following tables indicate the size, type and general condition of the structures. As can be seen, they are of mixed size and construction type but are generally in good condition throughout. Some relatively minor defects are present and the key information about each structure is presented below.
Table 2-6: Section 1 Structures - Construction Type and Size
NIRS Structure No of Span Width No Structure Name Structure Type Spans (m) (m)
30011 Tully Masonry Arch 1 1.87 9.85 60880 Magheramason Bridge Twin RC Pipes 2 2.7 17 62410 Magheramason Cattle Creep Concrete Box Culvert 1 4 18 60736 Burndennet Bridge Corrugated Steel Pipe 3 23 25.1 61210 Ballymagorry Concrete Arch/Masonry Arch 4 23.14 16.9 61448 Woodend Bridge Prestressed Concrete Beams 1 16.43 7.65 60887 Mourne Bridge Prestressed Concrete Beams 3 68 14 60875 Unnamed Masonry Arch 1 3.3 14
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Table 2-7: Section 1 Structures – Condition Ratings [Scores are based on draft Highways Agency standard performance measurement of highway structures (PMHS)]
NIRS Structure No Structure Name Average Condition Rating
30011 Tully Fair 60880 Magheramason Bridge Very Good 62410 Magheramason Cattle Creep Fair 60736 Burndennet Bridge Very Good 61210 Ballymagorry Very Good 61448 Woodend Bridge Fair 60887 Mourne Bridge Fair 60875 Unnamed Fair
2.2.6.3 Retaining Walls There are no retaining walls in Section 1.
The vast majority of these structures are in fair to very good condition.There are also a number of smaller structures (less than 1.8m span) along the route although these were not thoroughly inspected and no condition ratings were assigned.
2.2.6.4 Widening Issues Approximately half of the structures in Section 1 would be difficult to widen on line. Typically, the structure itself could be widened but there are existing constraints adjacent to it.
About one third of the structures could readily be widened on line, if required, although this would be considered further as the design is developed through Stage 3.
Of the remaining structures, it is considered that it would be more economical to completely replace 1 no., should it be required to accommodate a widened A5.
2.2.6.5 Structural Capacity The assessed capacity of the structures is reported in the NIRS database although the records were not complete at the time of inspection.
Of the 8 bridges, 6 have been assessed as having 40 Tonne HA loading capacity and are rated at 45 units of HB loading,
Two structures, Tully and Woodend, have no entries and these therefore would need review if the Preferred Route were to intersect them.
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2.2.7 Existing Pavement Conditions 2.2.7.1 Deflectograph From this analysis it was found that approximately 8% of Section 1 has a residual life of less than 5 years, 32% is between 5 and 20 years, and 30% has a residual life greater than or equal to 20years. Approximately 29% of the existing A5 in Section 1 has no data.
2.2.7.2 Visual Assessment using Digital Video Survey The data represented in this section applies to the entire length of the existing A5. Approximately 48% of northbound and 45% of southbound carriageways are considered to be showing signs of physical deterioration. No rutting is apparent in either direction. The northbound carriageway has the highest concentration of “two- wheel path” cracks while the southbound shows more “one-wheel path” cracks.
The visual survey method used replicates that of a UKPMS visual survey. Therefore, the result of the visual assessment was analysed similar to a UKPMS automatic pass. This process involves all the defects collected being analysed to produce constant defective lengths, which are then given a defect rating. This defect rating is in turn analysed to produce a condition index, i.e. structural or wearing course. The data was then further processed through bespoke scheme analysis software which utilises the condition index values to produce realistic scheme lengths. Therefore the defects recorded from the DV were broken down into condition indices and treatment options.
2.2.8 Baseline Environment 2.2.8.1 Air Quality There is one Air Quality Management Area (AQMA) within Section 1 covering Strabane. The declaration relates to historic coal fire burning.
Data for current concentrations related to the 2 traffic-based pollutants (nitrogen
dioxide (NO2) and particulate matter (PM10) within this section indicates that existing levels are well within statutory thresholds defined to protect human-heath (40 µg/m3 for both pollutants).
In relation to NO2, initial diffusion-tube data collected at key roadside locations indicates a range of concentrations between 9.03 – 33.4 µg/m3, the former being related Victoria Road (Grid Ref 238624, 409645) and the latter to a location on Derry Road (Grid Ref 234843, 398748).
In relation to PM10, monitoring data obtained from the AQMA in Strabane indicates that levels in this area of locally high concentration range from 20-25 µg/m3. Taking into account the presence of similar or lower traffic flows throughout other parts of the section and the absence of additional pollution sources similar in nature to those identified within the AQMA, it can be reasonably concluded that concentrations throughout the area do not exceed those monitored in Strabane and that levels throughout the corridor are well within the statutory thresholds.
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Receptors considered to be sensitive to changes in air quality are mostly concentrated within the main settlements of Strabane, New Buildings, Magheramason, Ballymagorry and Artigarvan. Their location in relation to the preferred corridor and distribution of more dispersed receptors in the form of hamlets and individual properties is shown in drawings 796036-3000-D-15122 and 15123. Taking into account the full extent of the Preferred Corridor, and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 6697 existing receptors who could be subject to increases or decreases in concentrations of the 2 pollutants. These include 6671 residential properties, 15 schools, 6 medical facilities and 5 residential care homes.
Preliminary calculations for regional emissions associated with traffic using the identified network within the section indicate total emissions of nitrous oxides (NOx)
in the order of 140 tonnes/annum. Equivalent figures for PM10 and Carbon (C) are 4 and 11,100 tonnes/annum respectively.
There is one statutorily designated ecological site associated with this section, McKean’s Moss ASSI, which could be potentially affected by nitrogen deposition associated with traffic related emissions.
2.2.8.2 Cultural Heritage Archaeology The review of baseline data and information derived from field walkover surveys has established the presence or potential presence of 246 sites or monuments within this section. The location of each is shown in drawings 796036-3000-D-14012 and. 796036-3000-D-14013.
There are 2 entries on the scheduled monuments record relating to the Strabane Canal, 51 known monuments of medium/low value, 56 industrial heritage sites of low value and 139 potential new sites located during the field walkover survey. The latter are of unknown value.
Figure 2-9: Strabane Canal
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Cist burial sites and raths are 2 of the notable early archaeology features associated with the section.
A number of Bronze Age cist burials; small rectangular stone lined pits are located on higher ground to the east. The most important relate to 2 burial cemeteries, one in the parish of Leckpatrick and one at Woodend, south of Ballymagorry. Their presence not only signals the potential that there could be undiscovered evidence of other similar sites, but that there may also be undiscovered evidence of wider prehistoric settlement in the area. Evidence for prehistoric settlement was uncovered during work on the Strabane bypass.
Raths are the most widespread and characteristic archaeological field monument in the Irish countryside. They consist of a circular area enclosed by an earthen bank and ditch. However, they are comparatively few in number in this section and are restricted to the higher ground at the edge of the Sperrin Mountains.
A newly identified site of possible importance relates to an earthwork site of unknown date or function located north east of Magheramason.
There are 3 ecclesiastical sites of note; the graveyard at Grange Foyle, the abbey at Rossnagalliagh and old Leckpatrick graveyard. All 3 are located in lower ground along the eastern fringes of the Foyle floodplain.
Many of the Industrial Heritage Sites relate to disused mills and associated ruins that provide a reminder of the importance of the linen industry locally and more widely. They are generally located along the watercourses where the river valleys descend through the Sperrin foothills.
In relation to archaeological potential beyond the sites and features identified during the preliminary walkover surveys, the form and relationship between the floodplain and low lying areas on the margins of the River Foyle and the Sperrin foothills are indicative of more general potential. The sheltered areas and small river tributaries associated with the foothills provide a higher potential for early settlement whilst the Foyle floodplain is more likely to yield up spot finds associated with its historic use, but not settlement.
Built Heritage There are 28 listed buildings and 9 Industrial Heritage Sites in this section. There are also 31 non-designated built heritage assets which the field survey team has identified during initial walkover surveys. The location of each is shown in drawings 796036-3000-D-14012 and 796036-3000-D-14013.
Three of the listed buildings are Grade B+ such that they are of national importance and high value. The remaining 25 are Grade B/B1/B2 such that they are of regional importance and medium value.
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Twelve of the listed buildings are located within Strabane; they include the 3 Grade B+ buildings, Gray’s Stationary Shop, the Church of the Immaculate Conception and Christ Church.
There is also a small grouping at Carricklee comprising Red House (Grade B), Gate Lodge (Grade B1), and the Courtyard (Grade B1). The grouping is associated with a Victorian estate. The remainder of the recorded and non-designated assets are dispersed throughout the section.
All of the 9 Industrial Heritage Sites are of low value.
The 31 non-designated built heritage assets are largely vernacular buildings of low value. The more notable include farm buildings and a gate lodge at Grange Foyle which comprise the remains of a large late nineteenth century house and farm. These are of regional importance and medium value.
Ballyfatten House, south of Strabane, and Roundhill House, at Woodend, are 2 non- designated buildings of particular note due to their size and architectural interest.
Historic Landscape Characterisation The baseline survey has concluded that there are no distinct areas of landscape or townscape where the combination of land use, field pattern, and complexes of archaeological/built form warrant consideration in terms of their cultural/historic sensitivity.
2.2.8.3 Landscape This section of the Preferred Corridor comprises part of the River Foyle valley as it flows north from the confluence of the River Finn and Mourne River at Strabane towards Londonderry. It is a large-scale and imposing landscape in which the wide valley floor flanking the river channel is framed by the prominent profile of the Sperrin Mountains to the east, the highest of the peaks being Slievekirk in the north and Owenreagh Hill to the east of Strabane. Beneath the profile of the mountains there is a series of foothills which form the transition from the high valley perimeter to the wide valley floor. Prominent foothills include Gortmonly Hill to the south of Magheramason and Knockavoe to the east of Strabane.
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Figure 2-10: The River Foyle
The preferred corridor broadly follows the line of transition, as it extends onto the lower foothills and valley floor, with the existing A5 corridor approximately marking the point of transition.
There is a significant break in the foothills in the form of the valley of the east-west flowing Burn Dennet, a significant tributary of the River Foyle. The tributary valley fans out such that the middle third of this section crosses the wide mouth of the valley.
The Sperrins south of the Burn Dennet valley mark the most northerly part of the Sperrins Area of Outstanding Natural Beauty (AONB). The relationship of the AONB to the preferred corridor is shown in drawing 796036-3000-D-11014.
A second, small tributary of the River Foyle, the Glenmornan River, joins the Foyle immediately south of the confluence with the Burn Dennet. The tributary’s catchment extends to the south east into the foothills and western margin of the Sperrins. The tributary valley becomes well-contained and intimate once it passes the northern limit of Ballymagorry and passes through Artigarvan.
There is a localised area of recognised landscape importance located east of Strabane in the form of Strabane Glen and the neighbouring area. The glen is a steeply incised gorge with ancient woodland which is self contained and highly distinctive.
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Figure 2-11: Strabane Glen New Buildings, at the northern limit of the Preferred Corridor and Strabane at the southern end of this section of the corridor constitute centres of population. Strabane is the residential, administrative and commercial centre of Strabane District, in between these two main centres, other small settlements include Magheramason, Bready, Ballymagorry and Cloghcor.
The western side of the Foyle valley is framed by a grouping of lower hills including a prominent grouping west of Londonderry, Binnion Hill and Croaghan Hill west of Strabane and Lifford. There is a significant break in the western profile between Binnion and Croaghan Hill where the valleys of the Swilly Burn and Deele River combine to establish an open vista out the west.
Landscape Character Areas and Landscape Character Zones Three of the sub-regional landscape character areas identified in the Northern Ireland Landscape Character Assessment are associated with this section of the Preferred Corridor: Foyle valley (character reference No.27), Burngibbagh & Drumahoe (character reference No.31) and Sperrin Mountains (character reference No.29). The extent of the character areas is shown in drawings 796036-3000-D-11013 and 796036-3000-D-11014.
At a more detailed level the assessment team has identified 15 Local Landscape Character Zones (LCZs). These are shown in drawings 796036-3000-D-11013 and 796036-3000-D-11014. Of these, 8 have been identified as being of good quality and high landscape value such that they would be the more sensitive of the areas to the introduction of the proposed dual carriageway. Three have been identified as having a low capacity to accept change allowing for the consideration of the potential to mitigate likely impacts. These 3 are:
• Ballougry Hill
• Foyle Floodplain
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• Knockavoe & Croaghan Hill.
Visual Context The following potential residential receptors have been identified:
• The southern fringes of New Buildings including a number of properties that occupy elevated locations overlooking the settlement;
• Properties in Magheramason with views of the adjacent open countryside;
• Dwellings to the west and east of Bready with views of the adjacent countryside, in particular those that overlook the floodplain to the west and the edge of Gortmonly Hill to the east;
• A number of properties that occupy a location adjacent to the crossing of the Burn Dennet by the existing A5, in particular those with open views to the west, including recreational areas;
• Properties within Cloghcor and several that occupy slightly elevated locations to the east of the existing A5;
• A number of properties within and around Ballymagorry, particularly those to the west, along with a number in the Glenmornan Valley between the towns of Ballymagorry and Artigarvan;
• A large number of properties on the urban fringe of Strabane, in particular those to the west with views of the River Foyle, along with a number to the east that occupy an elevated plot with views to the east; and
• A number of scattered properties occupying elevated locations that are afforded views of Strabane, the River Foyle and hills to the west.
In addition, there are views from a short section of National Cycle Network Route 93 which utilises the B48 between New Buildings to Drumagore to the west across the existing A5 and the Preferred Corridor.
Part of the Central Sperrins Scenic Driving Route uses the A49 as it runs from the east through Artigarvan and continues south along the A5 through Strabane.
These routes are promoted by Sperrins Tourism with the objective of introducing leisure drivers and tourists to the landscape and cultural interest of the Sperrins and their immediate environs.
2.2.8.4 Nature Conservation Statutory Designated Sites Designated sites located within or in close proximity to the section are indicated in Figures 796036-3000-D-13182 and 796036-3000-D-13183 and are scheduled below with an outline of the interests associated with them.
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• The River Foyle and Tributaries Special Area of Conservation (SAC) and Area of Special Scientific Interest (ASSI) - a plain to montane level watercourse noted for the presence of water-crowfoots and water-starwort and significant populations of Atlantic salmon. Otter are cited as a qualifying feature.
• The River Finn SAC (ROI) – Atlantic salmon and otter.
• McKean’s Moss ASSI – peatland flora and associated fauna.
• Strabane Glen ASSI – woodland flora and associated fauna.
The SAC is of international importance. The ASSIs are of national importance.
The internationally important Lough Foyle Special Protection Area (SPA) is located some 10km north of the Preferred Corridor. The SPA is recognised for its internationally important numbers of wintering wildfowl (notably whooper swans and pale-bellied brent geese) and its wintering population of bar-tailed godwit. Lough Swilly SPA is also located over 10km to the north west of the Preferred Corridor. There is emerging evidence that wildfowl associated with both SPAs use Grange Foyle as one of their foraging areas.
Non-Statutory Designated Sites There is one non-statutorily designated site associated with this section. This is a local wildlife site located to the north of the A5 Lifford roundabout between the Foyle River and the A5. The site supports wet scrub habitat and is of local value.
Classified Watercourses There are 5 watercourses classified under the EU Water Framework Directive (WFD) represented in the section. These comprise: Glenmornan River, Burn Dennet, River Finn, Mourne River and Cavanalee River.
All, with the exception of the Cavanalee River, have also been classified as “Salmonid Waters” under the EEC Freshwater Fish Directive. Detailed habitat suitability assessments have demonstrated that all of the watercourses, with the exception of the Glenmornan River, contain riparian habitats considered highly suitable for spawning by Atlantic salmon, and therefore, other freshwater fish.
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Figure 2-12: Cavanalee Gorge Habitats The more significant areas of habitat within the section are outlined below and shown in Figures 796036-3000-D-13182 and 796036-3000-D-13183. There is one record of a legally protected plant species within the section. This relates to the Killarney Fern found in Strabane Glen.
Woodland and Hedgerows
Significant examples of Woodland include:
• 18 hectares of nationally valued ancient woodland located within Strabane Glen; • 10 hectares associated with McKean’s Moss; • 3 hectares located at the Cavanalee Gorge; and • 4 hectares connected to Strabane Glen.
The hedgerows within the area, particularly the more intricate network associated with the Sperrin Foothills and tributary valleys of the River Foyle, are also an important biodiversity resource in relation to flora and fauna.
Peatland
The Bog Habitat forming the Mckean’s Moss ASSI is of national value.
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Grasslands and Marsh
The most important habitat is the Semi-Improved and Marshy Grassland found in the Foyle floodplain. This habitat is valued up to the national level within the ASSI and district level outside of the designated area.
Fauna Invertebrates
The surveys have identified 6 specific areas within the section where it has been concluded that habitats have the potential to support priority species and species of conservation concern (SOCC). Areas of high potential are shown in drawings 796036-3000-D-13188 - 796036-3000-D-13189 and include the River Foyle and Tributaries SAC.
Fish
The Burn Dennet, Glenmornan River and Mourne River support Atlantic salmon and brown trout. Habitat surveys undertaken by the Loughs Agency for the Foyle have identified important holding, nursery and spawning habitats within the catchment.
Other species found in watercourses within the section include eel, stone loach, minnow, smelt and flounder. The presence of salmonids provides a strong indication of wider ecological vigour in the freshwater ecosystem particularly with reference to macro-invertebrates, macrophytes and other freshwater fish species.
Birds
The most notable area of value for birds within the section is Grange Foyle. The areas value stems from its relationship to the Lough Foyle and Lough Swilly SPAs and use by significant species and numbers of wildfowl for foraging. Records relating to breeding birds within the section indicate that the area supports small to moderate populations of generally common species and a small number of less common species though the field surveys noted areas of habitat which are of potential value for a larger number of species than are currently recorded.
Otters
Otters are one of the key qualifying features of the Foyle and Tributaries SAC and are presumed to be present in high numbers in all watercourses. A total of 7 locations and stretches of watercourses have been identified during site surveys where the type and status of habitat are indicative of potential breeding sites for otter. These locations are shown in drawings 796036-3000-D-13188 - 796036-3000-D- 13189.
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Bats
There are a number of locations within the section where bat roosts have been identified and habitat types have been identified as being of biodiversity value in relation to bats (drawings 796036-3000-D-13188 - 796036-3000-D-13189). These include: upland oak wood, mixed ash woodland and wet woodland; the Foyle floodplain; improved pastures and wet grasslands adjacent to water courses; and buildings and outhouses.
2.2.8.5 Materials The solid and drift geology within the section are described in the geotechnical section of this chapter, paragraphs 2.2.4.2 and 2.2.4.3 respectively.
There are no statutorily designated sites of geological value within the section. There are, however, several areas which are recognised as having geological value. These include: the River Foyle and Tributaries SAC; Strabane Glen ASSI; Kittybane Quarry, north of New Buildings; and Strabane Quarry.
There are 3 landfill sites within the section; a disused landfill site at New Buildings and a further 2 at Strabane. There is also a site of former docking yards and a gasworks site associated with the Strabane Canal.
2.2.8.6 Noise The principal dominant continuous noise source within the section relates to traffic using the local road network with the busiest road being the A5. Preliminary LA10 measurements taken at the immediate roadside indicate existing traffic-related noise levels in excess of 70dBA. With increasing distance from the A5 levels will be noticeably lower as will levels associated with local roads within the section and throughout the rural areas that substantially constitute the Preferred Corridor.
Receptors considered to be sensitive to changes in traffic-related noise are mostly concentrated within the main settlements of Strabane, New Buildings, Magheramason, Ballymagorry and Artigarvan. Their location in relation to the preferred corridor and distribution of more dispersed receptors in the form of hamlets and individual properties is shown in Figures 796036-3000-D-15122 and 15123.
Taking into account the full extent of the Preferred Corridor, and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 48800 existing receptors who could be subject to increases or decreases in traffic related noise. These include 902 non-residential receptors including places of worship, rights of way and open spaces, and community facilities.
Site observations indicate that there are no continuous major sources of airborne vibration within the Preferred Corridor.
2.2.8.7 Effects on All Travellers There are a number of rights of way in the form of cycleways and footpaths within the section which could be potentially subject to disruption or loss of amenity value
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depending on proximity to or severance by any of the proposed alternatives. These are shown in Figures 796036-3000-D-12112 and 796036-3000-D-12113.
The routes include National Cycle Routes 92 and 93, both of which form part of the wider North West Trail, and the Faughan Valley Cycleway. Whilst there are no designated long-distance recreational walking routes associated with this section, there are 2 local routes; the Burn Walk near Strabane, and the Prehen Wood walking route near New Buildings.
Within Strabane, the verges, cycleways and footways of the A5 are used by people who are travelling between and around Strabane and Lifford. The towpath of the Strabane Canal is also used as a recreational footpath.
2.2.8.8 Community and Private Assets Population, Community Facilities and Access The distribution of population/settlement in the section and existing facilities in the form of shops, schools, churches, libraries, hospitals, sports and recreational facilities is shown in Figures 796036-3000-D-12112 and 796036-3000-D-12113.
New Buildings is a residential satellite of Londonderry with an industrial estate at the southern end of the settlement. Local facilities include a primary school, church and local shops.
Strabane is a district centre within which the principal retail and community facilities serving the needs of local residents and the surrounding settlements and communities are located. The principal retail area, council offices, library, theatre and a small number of schools and churches are concentrated north of the River Mourne. There is a travellers halting site east of the A5 north of the Asda roundabout. The most substantial areas of residential development are located to the south of the river. Access to the core retail and community facilities from these areas is available via Bridge Street. Facilities south of the river include schools, a church, the Riversdale Leisure Centre and playing fields and the Ballycolman Golf Course along the margins of the Mourne River. The existing A5 follows an alignment that broadly defines the western edge of this southern part of the settlement though it does sever the residential area of Castletown from the main mass of the settlement south of the river.
There is an important relationship between Strabane and Lifford in the Republic of Ireland which is currently secured via the Lifford Bridge. The two communities share several cross border facilities. The Lifford Community Hospital is used by residents of Strabane and the surrounding areas, as is a cinema and greyhound track. Residents of Lifford and its hinterland use the shopping and leisure facilities available within Strabane including the Riversdale Leisure Centre, bars and restaurants.
Outside of New Buildings and Strabane, settlement comprises the villages of Magheramason, Ballymagorry and Artigarvan, a significant number of small, generally dispersed hamlets and individual farmsteads. Maghermason and Ballymagorry are both located on the existing A5 and Artigarvan on the B49. The
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hamlets take the form of small groupings of dispersed properties located along the A5 and B49 and at crossings of the network of local roads. There is a discernibly greater concentration of hamlets and individual properties along the A5 corridor and to the east of the road, particularly where the corridor crosses the Burn Dennet and Glenmornan valleys. Ballymagorry and Artigarvan share a primary school and leisure facilities.
Communal facilities associated with the villages and hamlets comprise local shops, churches and public houses. There are primary schools at Bready, Cloghcor and Artigarvan. There has also been a recent significant development of the cricket ground at Magheramason (the ground is one of those used for first class matches including international matches).
Outside of Strabane, access between communities and their associated facilities is substantially reliant on use of the car or local bus services, there being no significant network of rights way in the form of footpaths that link places and facilities.
Private Assets The dominant land use is agriculture with most of the area being classed as Best and Most Versatile (BMV) land (Grades 3A/2/1). The extent of BMV land in the section is shown in Figures 796036-3000-D-12135 and 796036-3000-D-12136.
Between New Buildings and Bready the land is primarily Grade 3A with occasional pockets of Grade 2. Between Bready and Ballymagorry there is Grade 2 land across the wide alluvial Burn Dennet valley. South of Burn Dennet to Sion Mills the land is predominantly Grade 3A with occasional pockets of Grade 2.
Dairy farms are concentrated in the northern part of the section between New Buildings and the Burn Dennet with a greater concentration on the foothills and alluvial valley floor of the watercourse east of the A5.
The locations of planning approvals granted during the last 3 years are shown in Figures 796036-3000-D-12141 and 796036-3000-D-12142. Applications of specific note in relation to the alternatives comprise a cluster of applications at Magheramason, applications adjacent to the existing A5 on the northern approach to the town and an application east of the A5 mid-way along the throughpass. Cognisance was also given to planning applications in the vicinity of the roundabout near ASDA in Strabane.
Figures 796036-3000-D-12129 and 796036-3000-D-12130 show the development limits for New Buildings. Magheramason, Bready, Cloghcor, Ballymagorry, Artigarvan and Strabane.
2.2.8.9 Road Drainage and the Water Environment Surface Water This section of the Preferred Corridor is located within the valley of the River Foyle and entirely within the associated catchment. The principal watercourses comprise; the River Foyle, Burn Dennet, Glenmornan River, River Finn, River Mourne and
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Cavanalee River. The watercourses and extent of existing floodplains associated with the watercourses are shown in Figures 796036-3000-D-17096 and 796036- 3000-D-17097 and described in paragraph 2.2.5.
All of the watercourses have been classified as moderate to very good for chemical water quality and moderate to good for their biological water quality.
Figure 2-13: The Burn Dennet Groundwater The impermeable bedrock that extends across this section of the Preferred Corridor has little or no groundwater potential. It is however overlain by superficial alluvium deposits, sands and gravels associated with the main watercourses in the area which are locally important water-bearing strata and which are classified as being moderately vulnerable in relation to groundwaters. These are classified as being of good quality chemically and biologically.
Peatlands Two designated peatland sites are located in the Preferred Corridor: Gortmessan Marsh, which forms part of the River Foyle and Tributaries SAC and McKean’s Moss ASSI. The condition of the former appears reliant on the high groundwater level locally and periodic flooding from the River Foyle whilst the latter is fed by rainwater.
Water Resources There are no public water abstraction points within the section. There is, however, 1 surface water and 8 groundwater abstractions. These are for commercial, agricultural and/or private drinking supplies. There are 7 licensed discharge consents and 5 sewage treatment plants. The location of these various abstractions and discharges is shown in Figures 796036-3000-D-17096 and 796036-3000-D- 17097.
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2.2.9 Existing Traffic Conditions for Section 1 2.2.9.1 Traffic Flows
Figure 2-14: Traffic flows in vicinity of Section 1 of the scheme during May 2008 (daily Monday to Thursday average, excluding bank holidays)
Figure 2-14 shows traffic flows along roads in Section 1 of the A5 WTC scheme. These values are average 24 hour weekday vehicle flows (Monday to Thursday). The figure shows that the road with the highest flow in this section is the A38 Lifford Bridge between Strabane and Lifford, with a 24 hour flow of 19,600 vehicles.
The route of the A5 is illustrated on this plan and has a 24 hour traffic flow of between 12,500 and 15,200 vehicles per day.
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Figure B-1 to Figure B-3 inclusive within Appendix B give detailed traffic conditions from surveys at a location on the A5 within Section 1. This is the location shown by the green triangle on Figure 2-14 above, to the south of New Buildings.
Figure B-1 presents traffic flows for the long-term Automatic Traffic Count (ATC) at NIRS site 390. This site is on the A5 to the south of New Buildings and is used to represent Section 1, as denoted by the green triangle on Figure 2-14.
Figure B-1 shows little seasonal variation at this location, and that traffic flows for May 2008 are representative of flows throughout the whole of 2008.
Figure B-2 illustrates the average daily variation of flow during May 2008 at this location. This shows that the principal movement of traffic is northbound in the morning peak, between 8am and 9am, and southbound in the afternoon peak, between 5pm and 6pm. The peak flow in the afternoon is marginally lower than in the morning, though the flows during adjacent hours are relatively higher than those adjacent to the morning peak. This indicates a more spread out peak in the afternoon than in the morning.
The maximum hourly flow along this section of road is approximately 700 vehicles per hour in a single direction between 8am and 9am.
In the morning peak hour the northbound flow is 50% higher than the southbound flow. In the afternoon peak hour a similar pattern applies with the southbound flow being 50% higher than the northbound flow. This is likely to be due to the proximity of the location to Londonderry, and the strong tidality of commuter movements.
A Manual Classified Count (MCC) was conducted at the location of the green triangle in Figure 2-14, on Wednesday 30 April 2008. The proportions of vehicle types at this location are shown in Figure B-3. This shows a high proportion of car journeys on this section of road, which is at its greatest during the afternoon peak period. The proportion of LGVs is reasonably constant at about 10% throughout the day. The proportion of HGVs is similar to that of LGVs in the morning peak and interpeak periods, though it is much reduced in the afternoon peak period.
The proportions of motorcycles, buses and coaches are very small.
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2 1 9 2 1
NORTH 1 15 1 3 80 0 0 1 4 95 7 31 1 3 8 04 1 9 2 4 1 7 3 3 9
5 0 5 3 3 5 1 9 7 3 9 7 0 1 3 3 1 2 2 1 60 3 12 27 7 23
Figure 2-15: 12 hour Vehicle Flows at junction of the A5 with the A38 in Strabane on Wednesday 30 April 2008 The turning movements of traffic at the junction of the A5 with the A38 (Lifford Bridge) are shown on Figure 2-15. This shows the principal movements as straight ahead on the A5 between the north and the south, between the A38 and the B72 Railway Street, and between these roads (A38 and B72) and the A5 to the south. Movements between the A38/B72 and the A5 to the north are not so significant.
2.2.9.2 Major Traffic Movements During May 2008 Roadside Interview surveys were carried out to determine the origins and destinations of traffic travelling along the A5 at a series of locations. The results of this survey are used in the following analyses to indicate the typical trips that pass along Section 1 of the A5.
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Figure 2-16: Sectors used to describe Traffic Movements Figure 2-16 illustrates a sector system used to summarise locations in Northern Ireland and the Republic of Ireland. Sectors 1 to 4 are along the A5 in its immediate vicinity. Sectors 5 and 6 represent locations within Northern Ireland both of which are within 50miles of the A5, whilst sectors 7 and 8 denote the east of Northern Ireland. Sectors 9, 10 and 11 represent the Republic of Ireland. Sector 9 represents Donegal while sector 10 extends to the south as far as Dublin while sector 11 covers the western and southern most regions of the Republic of Ireland.
The traffic movements are reported as average hour vehicle movements for the morning peak, the interpeak period and the afternoon peak.
Separate analyses of half-hourly traffic flows along the length of the A5 have identified a morning peak period between 7:30am and 9:30am. This is not the same as the maximum hourly peak flow for this section, which is between 8am and 9am, as shown in Appendix B Figure B-2. The maximum hourly flow does however occur within this morning peak period.
Similarly, an afternoon peak period has been determined between 4pm and 6pm, and the interpeak period has been selected to be between 11am and 3pm.
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The location of the survey used to represent traffic movements through Section 1 is shown on Figure 2-17. This location is on the A5 at Ballymagory, to the north of Strabane.
Figure 2-17: Location of survey used for Traffic Movements through Section 1
Within Appendix B, Table B-2 to Table B-7 inclusive report these traffic movements for a May 2008 weekday.
These tables show that the existing A5 in Section 1 is used principally by trips to and from the Londonderry area.
During the morning period, the peak flow direction is northbound. During this period more than three-quarters of all northbound traffic is bound for sector 1 (Londonderry), approximately half of which originated in sector 2 (Strabane). The other locations
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generating significant volumes of northbound traffic in the morning peak are sector 3 (Omagh) and sector 5 (Enniskillen & Co Fermanagh)
Most of the southbound journeys in the morning peak actually start and end in sector 2, or else begin in sector 1 and are bound for sector 2. In either case they are therefore relatively local journeys of 25 miles or less.
Table B-4 and Table B-5 show that traffic movements in the interpeak period follow a similar pattern as in the morning period. During the interpeak period there are an increased number of journeys to or from locations in the Republic of Ireland to the south (sectors 10 and 11).
During the afternoon period the peak flow direction along Section 1 is in the southbound direction, as shown by Table B-6 and Table B-7. Most of these southbound journeys begin in sectors 1, 2 and 9 (County Donegal), travelling to sector 2 or sector 3.
More than two-thirds of northbound journeys during the afternoon time period are bound for locations around Londonderry, sector 1.
2.2.9.3 Journey Time Analyses A journey time analysis was undertaken using Automatic Number Plate Recognition (ANPR) survey data. The analysis was spilt into 10 routes between New Buildings and Aughnacloy South as shown in Figure 2-18 below. Each of these 10 routes was given 2 route identifiers, odd numbers representing the southbound flow and even numbers representing the northbound flow.
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Figure 2-18: A5 Corridor Journey Time Route Layout Section 1 combines routes 1/2 and 3/4 and is approximately 23km long, running between New Buildings and south of Strabane. The overall southbound route along the length of Section 1 has been given the route identifier 101 and its corresponding northbound route has been given the identifier 102.
The ANPR surveys were conducted on Tuesday 29 and Wednesday 30 April 2008 and data was collected during the three time periods AM Peak (07:30-09:30), interpeak (11:00-15:00) and PM Peak (16:00-18:00) on each survey day and then combined together to give a 2 day sample for each time period. It should be noted
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that sample flows include only vehicles that traverse an entire route and not those that enter or leave within a route.
The results for Section 1 are shown in Table B-8 within Appendix B.
The results presented in Table B-8 show that the average speeds are very similar between time periods. However, around Strabane (routes 3/4) speeds along the A5 are about 20km/h lower than on the rural length to the north of Strabane (routes 1/2). This reduction is likely to be due to delays at a number of roundabouts and signalised junctions along the A5 as it passes Strabane. It is also noted that within Strabane the highest speeds occur in the AM Peak. This appears counter-intuitive given this time period also has the highest flows. However, the speeds are relatively constant throughout the day.
2.2.9.4 Section One Accident Data Analysis Accident data has been analysed at three levels - 'link only', 'junction only' and 'links & junctions combined'. These types correspond to the way in which PIAs are reported in COBA/DMRB. The 'combined link and junction' analysis refers to all accidents occurring on a section of road, and provides an overview of general accidents rates. ‘Link only’ and ‘junction only’ analysis can be used to determine whether a bias exists within either accident rate type, which could affect the overall combined rates on the link. Personal Injury Accidents (PIAs) are categorized as fatal, serious or slight depending upon the severity of the worst casualty in each accident. As part of the analyses described in the report, fatal and serious accidents have been summed together and shown as a proportion of all PIAs (F+S/PIA ratio) i.e. the ratio of "fatal + serious" to "fatal + serious + slight" accidents on any given link or junction. For example if there were 10 PIAs on a link and 2 were fatal, 3 were serious and 5 were slight, the F+S/PIA ratio would be 0.5 [(2+3)/10].
Combined Link and Junction Analysis – Appendix B, Table B-9 Main line links in Section 1 consistently had a lower overall accident rate than the Cost Benefit Analysis (COBA) default proportions. The difference between COBA default and observed rates was greatest between Strabane and Sion Mills, where the observed rate was only 13% of the COBA default.
The A5 link between Londonderry and New Buildings had a higher F+S/PIA ratio than the COBA default. All other main line links had a lower F+S/PIA ratio, most notably the A5 between Strabane and Sion Mills, which had zero fatal or severe accidents on the link itself and its junctions. The length of the A5 between New Buildings and Strabane was the only link observed in Section 1 to have a fatal accident; in fact, 2 occurred on this link and it’s junctions during the study period. The study period for the accident analysis was 2003-2006 inclusive i.e. four years' duration. 2006 was the latest complete (whole year) set of data which had been issued in a 'final' version at the time the report was written. However, despite this the F+S/PIA rate is lower than the COBA average.
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Two key side roads in Section 1 had a higher than expected accident rate when compared with COBA defaults. These were the B49 from the A5 to the limit of the study area and the B72 within Strabane (urban).
The B49 is located to the east of the A5, intersecting with the A5 at a location south of Ballymagorry and passes through Artigarvan towards Dunnamanagh. It is a narrow rural road with numerous tight bends and steep gradients. The observed PIA rate was 0.56 compared with the COBA average of 0.40.
The B72 between Strabane and Victoria Bridge offers a potential alternate route to the A5, to the east of the river Mourne. The B72 urban section within Strabane had an accident rate nearly twice that of the COBA default, with a total of 31 PIAs on the link and its junctions between 2003 and 2006. This is equivalent to an observed accident rate of 1.48 compared with the COBA average of 0.84. All but one of these accidents had a slight severity and therefore the F+S/PIA ratio on this link was low at about a quarter the value of the COBA default.
Of the key side roads assessed, 3 had F+S/PIA ratios higher than the COBA default. These were the A40 between Londonderry and the limit of the study area, the B49 between A5 and the limit of the study area, and the A38 between Strabane and Lifford.
The A40 at this location offers a potential alternative route to the A5, linking with the A5 to the south at Lifford in the Republic of Ireland.
The observed F+S/PIA ratio for the B49 was 0.30 compared with the COBA default of 0.22. Three of the 10 PIAs occurring on this link were serious.
The A38 experiences a substantial amount of traffic. The observed F+S/PIA ratio at this location was only slightly higher than the COBA default.
Link-Only Analysis – Appendix B, Table B-10 For the link-only analysis, the observed accident rate on the A5 in Section 1 was lower than the COBA default across all the scheme sections. The A5 between Strabane and Sion Mills experienced the lowest number of accidents, only 2 PIAs both of which were slight.
The observed F+S/PIA ratios were consistently less than COBA default values on all A5 links in this section. However, due to both the fatal accidents on the A5 between New Buildings and Strabane being classified as ‘link-only’, the F+S/PIA ratio was much closer to the COBA default than with a combined link and junction comparison.
The key side roads in Section 1 exhibit the same pattern in the link-only analysis as they did in the link and junction analysis. Two links, the B49 from the A5 to the eastern limit of the study area and the B72 within Strabane (urban) both had accident rates exceeding the COBA default.
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Eighteen PIAs occurred on the B72 within Strabane (urban), but only one of these was serious. Consequently, the observed F+S/PIA ratio was lower than the COBA default. However, 3 of the 7 PIAs on the B49 between the A5 and the study area limit were serious, making the observed F+S/PIA ratio (0.43) higher than the COBA default (0.24). In addition the A40 between Londonderry and the limit of the study area, and the A38 between Strabane and Lifford had observed F+S/PIA ratios higher than their COBA defaults. These are the same routes as for the ‘combined link & junction’ analyses, though the disparity on the A38 was greater for link-only analyses.
Junction Analysis – Appendix B, Table B-11 In Section 1, only one strategic junction had a greater number of observed PIA accidents (between 2003 and 2006) than the COBA average value. This was the junction between A5 Barnhill Road and B72 Derry Road, referred to as Junction 2 in Table 2-20 within this report. This junction had 5 PIAs between 2003 and 2006, 4 of them with slight severity and the other one with serious severity. COBA default rates predict only 4 accidents at this junction over the course of 4 years.
For all other strategic junctions the observed PIA rate was no more than half the COBA average.
Junction 6, where the A5 Melmount Road/Orchard Road intersects Melmount Road and Strathmore Place, had no personal injury accidents during this time period, whereas over 4 years, COBA would have predicted a total of 3 accidents at this junction.
Junction 3 is the main roundabout junction between the A5 and the A38 Lifford Road and B72 Railway St in StrabaneIt has had 5 personal injury accidents in the 4 year period compared with a predicted number of 10 according to COBA default calculations it should be noted that a new junction layout was constructed here in 2006. . One of these accidents was serious. Because the number of total accidents was low, the observed F+S/PIA ratio (0.20) is above that expected by COBA default proportions (0.08).
All other strategic junctions in Section 1 had a lower observed F+S/PIA ratio than COBA default. Junctions 1, 4, 5 and 6 each had an observed F+S/PIA ratio of 0, which results from having no fatal or serious accidents.
Summary The PIA rates on the A5 in Section 1 were generally less than the defaults expected in COBA. This also applied to 3 of the 5 key side roads.
The severity of accidents on the A5 were also generally less than COBA averages, as were they on the majority of key side roads.
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2.3 Existing Conditions – Section 2 South of Strabane to South of Omagh 2.3.1 Description of Current Network The chainages referred to in this chapter are taken from the existing assessment drawings, which for Section 2 are numbered 796036-0800-D-00019 to 796036-0800- D-00038, and are included in Volume 3 for reference.
In Section 2, the existing A5 carriageway is approximately 31km in length. The existing A5 through the towns of Sion Mills and Omagh, as well as the village of Victoria Bridge, lies outside of the extents of the Preferred Corridor, as illustrated in Figure 2-19.
The A5 runs through Sion Mills along the west of the Mourne River outside the Preferred Corridor. South of Sion Mills the A5 re-enters the Preferred Corridor for a length of 1km. The road follows the bend of the Mourne River where it passes close to Seein Bridge and intersects with the B165 before exiting the corridor again. Following its exit from the Preferred Corridor, the A5 runs through Victoria Bridge, crossing the B72 near the middle of the village. The A5 re-enters the Preferred Corridor immediately south of the village. Between Victoria Bridge and Newtownstewart the existing A5 runs in close proximity to the western banks of the Mourne and Strule Rivers before bypassing the local town of Newtownstewart. To the north of Newtownstewart the B164 (Deerpark Road) joins the A5 at Lower Deerpark from the west. The Newtownstewart Bypass, which opened in 2002, follows a route around the northeast of the town where it is intersected by the B46 Plumbridge Road.The Bypass crosses the Strule River twice before tying back in to the original A5 to the east of the town. South of Newtownstewart, the road continues to run in close proximity to the western banks of the River Strule steadily rising to the site of the Ulster American Folk Park. From here the level of the existing A5 generally falls continuing south past Mountjoy Bridge and Poe Bridge before entering the outskirts of Omagh. The A5 exits the Preferred Corridor immediately south of Poe Bridge, and continues through Omagh in a south easterly direction. The A5 intersects a number of side roads as it passes through the town, including the B50 and the A32. Towards the southern extents of Omagh, the A5 crosses the Drumragh River before continuing south along the Omagh Throughpass. The A5 re-enters the Preferred Corridor at Doogary.
There are natural and man-made constraints along the existing A5 which obstruct the possibility of on-line widening in this section. Man-made constraints comprising:
• quarries located between Victoria Bridge and Newtownstewart (Ch. 32,450 - 33,150)
• Pubble Graveyard north of Newtownstewart bypass (Ch. 37,050),
• The Mellon County Inn (Ch. 45,750)
• Garage and Restaurant at Mountjoy Bridge (Ch. 47,500).
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There are also a number of settlements comprising commercial properties such as shops, filling stations, public houses and housing throughout the stretch of the existing A5 from Strabane to Omagh.
The settlements in Section 2 fall within the Omagh Area Plan 1987-2002. Like any developments, housing industry, commerce, community facilities and recreation/open space are situated in convenient locations in the community. Various cultural, landscape and environmental features are present within the Preferred Corridor of Section 2 such as Harry Avery’s Castle, a scheduled monument, located to the west of Newtownstewart, the Strule River SAC and Grange Wood ASSI. Major planning application in the last 8 years within this section include 2 above ground slurry stores to the north of Victoria Bridge (approval 2006), quarry extensions to the south of Victoria Bridge (status pending), an expansion to the industrial and commercial development adjacent to the A5 between Victoria Bridge and Newtownstewart (approval 2006). A Pumping station adjacent to the northern River Strule crossing (status pending), expansion of the Mellon County Inn (status pending). An extension to the Ulster American Folk Park (approved 2008), replacement of a garage at Mountjoy Bridge (approved 2003), a replacement Church Hall at the end of Rash Road south of Mountjoy (approved 2004), an underground slurry store north of the Fairy Water crossing (approved 2005) and a water treatment works apparatus adjacent to the existing A5 for 1km on the approach to Poe Bridge (approved 2005).
The main economic activity in the area is agriculture. There are expansive areas of Best and Most Versatile lands; private and Department of Agriculture and Rural Development (DARD) Woodlands, and agri-environmental schemes. The whole of the Rivers Strule, Mourne, Finn and Foyle and their tributaries are well known in Northern Ireland for game and coarse fishing, supporting a diverse mixture of fish and river dynamics The Strule River flows in a northerly direction from Omagh towards Strabane before converging with the River Derg at Bunderg just north of Newtownstewart, to form the Mourne River. The Mourne River continues towards Strabane where it converges with the Finn River to form the River Foyle. Major tributaries known to be used extensively by anglers consist of the Fairy Water (originating in the Bolaght Mountain and running east towards Omagh) and the River Derg (running east from the Killeter Uplands to Ardstraw).
Within Section 2, the existing A5 is utilised by several bus services. Goldline Express services 273 and 274 use the full length of existing A5, running up to 10 times daily, and Ulsterbus service 97 utilises the existing A5 between Newtownstewart and Omagh running up to 6 times daily. The existing A5 also crosses the National Cycle Network Route 92 around Newtownstewart.
A number of A and B Class routes join the existing A5 within the extent of Section 1. The routes are identified in Table 2-8, along with the local town with which they connect.
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Table 2-8: Major Routes joining existing A5 within the Preferred Corridor within Section 2 Route Chainage on Existing A5 Connecting Town
B164 35,950m Ardstraw
36,400m (via Strabane B84 Drumquin Rd)
B165 37,700m Douglas Bridge
B46 37,700m Plumbridge/Gortin
B50 51,240m Drumquin/ Castlederg
A32 53,130m Enniskillen
B72 30,400m Victoria Bridge
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Figure 2-19: Overview of section 2: Preferred Corridor, Development Limits and Intersecting Routes/Links within Section 2
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2.3.2 Existing Highway Conditions The majority of the existing A5 from the South of Strabane to the South of Omagh is derestricted, and is therefore subject to the national speed limit of 60mph. In accordance with the Design Manual for Roads and Bridges (DMRB) TD9/93, this equates to a design speed of 100kph. A geometric assessment of the stopping sight distance, the horizontal and vertical alignments has been carried out. The full overtaking sight distance assessment has also been carried out for the existing carriageway. This gives a safe distance for overtaking on single carriageways, and is generally only realistically achieved in areas of relatively flat terrain.
The geometric assessment of the existing A5 was carried out using the existing speed limits and is graphically presented in drawings 796038-0800-D-00019 to 796038-0800-D-00038, in Volume 2 and summarised (lengths greater than 100m) in Appendix A. The drawings note the variances in speed limit. As shown on these drawings, there are 22 areas that are sub-standard to such an extent that they would require departures from the current standard TD9/93 (DMRB 6.1.1).
Section 2 of the A5 is approximately 31km in length and runs south from Strabane towards Omagh. There are several lengths of the existing A5 within Section 2 which lie outside of the Preferred Corridor, namely through Sion Mills, Victoria Bridge and Omagh. As a result the length of the A5 within the Preferred Corridor is therefore reduced to 21km within Section 2.
With nearly 200 residential, farm and commercial accesses directly onto the road, the A5 is classified as a high density access constraint, which has an impact on both traffic speed and safety. The A5 is generally undulating and lies at the foot of several hills: the highest point is 82m AOD at the site of the American Folk Park and the lowest point of the road is 21m AOD and lies between Sion Mills and Victoria Bridge.
Within the Preferred Corridor, the cross-section width of the carriageway is approximately 7.3m throughout, with the hard strip width varying between 0.3m and 1.0m. The 0.3m wide hard strips generally occur on the older sections of the A5, with the cross section along the Newtownstewart Bypass being to the higher 1.0m wide standard.
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Figure 2-20: Existing A5, north of Newtownstewart Following its departure from Victoria Bridge, the road is generally undulating and climbing on the approach to Newtownstewart, running approximately parallel to the River Mourne in a south-easterly direction along the lower slopes of Clady Hill and Bessy Bell. The minor roads joining this section of the trunk road generally have national speed limits in force, and do not generally have road markings except at their junctions with the A5. There are 2 right turn lanes situated along this length, increasing the overall carriageway width from approximate 7.3m to 9.5m over short and isolated lengths.
Figure 2-21: River Strule Crossing, Newtownstewart Bypass The Newtownstewart Bypass was constructed in 2002 to divert the original A5 around the town. The bypass (figure 2-21) commences to the northwest of Newtownstewart, approximately 0.7km before the first crossing of the River Strule. The carriageway width along the bypass is 7.3m with 1m wide hard strips. Along the length of the bypass, there are three areas where the carriageway width increases to approximately 11.0m to facilitate right turn lanes. The bypass ties back in to the original A5 to the east of the town, approximately 1.2km south of the second crossing of the River Strule.
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Figure 2-22: Existing A5 with central hatching, Mountjoy Following the Newtownstewart Bypass, the carriageway width remains at approximately 7.3m with 0.3m wide hard strips until it reaches Poe Bridge at the extents of Omagh. Within this section, there are 3 areas where the carriageway width has been widened to approximately 9.0m to include right turn lanes. There are also several lengths where traffic calming measures have been provided through provision of a hatched area between the north and southbound running lanes. The road is generally undulating in this section, and reaches a high point around the Ulster American Folk Park, reducing in level by approximately 20m before reaching Poe Bridge. The minor roads joining this section of the trunk road generally have national speed limits in force.
2.3.3 Utilities Electricity, potable water, foul water and various telecommunications are the main services located within the Preferred Corridor. These services are concentrated in, and around, settlement areas, however, transmission lines and trunk mains also traverse the rural areas of the scheme corridor. The existing A5 provides the main utility corridor in the vicinity of the proposed scheme. Details of the major ultilities plant can be found in drawings 796036-0100-D-20001 and 20002 in Volume 3.
2.3.3.1 Electricity NIE have an 110kV conductor extending from the south of Strabane running parallel and due east of the Preferred Corridor before crossing into it, south east of Newtownstewart. From this point it continues southerly down the approximate centre of the Preferred Corridor before terminating at a substation, south east of Omagh. A second 110kV supply, consisting of 7 conductors supported on steel pylons runs from the aforementioned substation, located south east of Omagh, around the east side of Omagh. This supply line crosses over the boundary into the scheme corridor as it progresses north at a point to the north east of Newtownstewart.
A length of 33kV supply is located within the Preferred Corridor, running to the west of the A5 from Ardstraw to Mountjoy at which point it intersects the A5, crossing to the east side of it. The cables then exit the Preferred Corridor at this point before
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skirting to the east of Omagh and entering the substation to the south east of the town. From this substation a 33kV supply runs in a westerly direction, 2 of these 33kV conductors traverse the Preferred Corridor and exit it to the south east of Omagh via Clanabogan. Details of this can be seen on the drawings as referenced above.
Due to the amount of transmission lines located within the Preferred Corridor it is likely that remedial works will be required as a result of the proposed scheme, the degree of which will depend on the route selected.
NIE also have networks of medium and low voltage distribution cables within settlement areas.
2.3.3.2 Water Mains and Sewers Two 300 – 450mm diameter water mains, which radiate from the vicinity of Victoria Bridge, dissect the Preferred Corridor, 1 running due west and the other in a south westerly direction from Victoria Bridge. Another 300 – 450mm diameter watermain runs east from Drumquin then enters the Preferred Corridor, running perpendicular to it, and exits before skirting to the north of Omagh.
The majority of the NIW sewerage network in Section 2 is concentrated within the settlement areas of Sion Mills and Newtownstewart.
2.3.3.3 Telecommunications BT have significant underground and overhead apparatus that generally follows the existing A5. This apparatus is more concentrated in the vicinity of settlement areas.
Virgin Media, Eircom and Bytel have apparatus within this section, again within a common trench, most notably the stretch of fibre optic cables contained within the existing A5 due south of Newtownstewart.
T-mobile, O2, Orange and Vodafone have a number of mobile phone masts located throughout Section 2, in close proximity to the existing A5.
2.3.3.4 Miscellaneous Current utility information indicates that there are no gas pipes or wind farms located within the Preferrred Corridor in Section 2.
2.3.4 Geotechnical Drawings of the ground conditions for Section 2 are split into the following three categories and can be found in Volume 3.
• Digital Terrain Model/ Drift Geology on drawings 796036-0600-D-20001 & 20002
• Slope Gradient/ Potential Contaminated Land/ Quarry Exents on drawings 796036-0600-D-20003 & 20004, and;
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• Solid Geology on drawings 796036-0600-D-20005 & 20006.
2.3.4.1 Topography The topography of the Section 2 Preferred Corridor is extremely variable and ranges from flat land along the floodplains of the river courses to the moderately sloping foothills of the Sperrin Mountains.
From the northern section boundary to the confluence of the River Derg and the Mourne/Strule River, the topography generally slopes down towards the River Mourne in the east of the Preferred Corridor. The highest ground is at approximately 120m AOD in the west and slopes down to 40m AOD in the east at gradients of between 1:10 and 1:5.
From the confluence of the River Derg and Mourne/Strule Rivers, southwards to Newtownstewart, the Preferred Corridor straddles both banks of the Strule River. The land to the north of the Strule River slopes down gently from the Sperrin Mountains AONB at gradients of between 1:10 to 1:5 and up to 1:3 gradients along the edges of the floodplain. The land to the south of the Strule River (part of the Foyle River and tributaries SAC), between the River Derg and Newtownstewart, is noted to be fairly flat. However, in the Deer Park area the topography is noted to be more undulating with differences in height of between 100m AOD and 60m AOD.
The area within the Preferred Corridor to the south of Newtownstewart slopes down to the north east from Bessy Bell at a height of 120m AOD, to the town at approximately 50m AOD at steeper slopes than 1:5 gradients.
From the south of Newtownstewart to the Ulster-American Folk Park, the Preferred Corridor is constrained to the west by Bessy Bell and to the east by the Sperrin Mountains and the Strule River. The topography of the area is moderately sloping down from the west at 220m AOD to 50m AOD in the east, at gradients of between 1:10 and 1:3. This section follows the west side of the U-shaped Strule Valley, which is flat bottomed, with steep side slopes. There is a narrow shelf half way up the western valley side, which is occupied by a minor road. The existing A5 is benched on to the lower valley side slope to the west of the River Strule.
From the Mountjoy area southwards to the Fairy Water, the topography of the land is generally very flat, with infrequent drumlins in the west of the Preferred Corridor. The land is generally 50 to 70m AOD in this area, with the drumlins being between 10 and 20m above the surrounding area.
From Gillygooly to the southern Section 2 boundary, the landscape is dominated by drumlins and undulating land, with side slopes of between 1:10 and 1:5 and ranging in heights of between 150m AOD to 60m AOD. The land is noted to be approximately 20m higher in the west than in the east of this southern part of the corridor.
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2.3.4.2 Solid Geology The underlying geology of the Preferred Corridor is structurally complex, but falls into 2 distinct provinces: Precambrian strata to the north of the Omagh Thrust Fault and Devonian and Carboniferous strata to the south of the fault.
The Omagh Thrust Fault is a sub-horizontal thrust fault that passes through the Preferred Corridor at the southern limits of Section 2, immediately to the south of Omagh. The fault line trends in a south west to north-easterly direction. The Precambrian strata from the north have been thrust southwards and over younger rocks beneath, in the form of a large overturned fold, known as the Sperrins Nappe. The strata encountered to the south of the Omagh Thrust Fault are predominately Upper Devonian Shanallagh Formation which comprises sandstone and mudstone. A small wedge of Carboniferous Slievebane Group strata is also noted along the fault boundary in the centre of the Preferred Corridor.
North of the thrust, in the area to the west of Newtownstewart, the Sperrins Nappe takes the form of an asymmetric anticline, the axis of which trend from the south west to north east. Newtownstewart Formation, described as thickly bedded quartzose psammite with thin pelite interbeds, is the stratum at the centre of the nappe. Due to the deformation that the folded nappe has been subject to, the strata differ between the north west and the south east limb. The strata on the north west limb have moderate dips towards the north west and comprise Dungiven Formation and Claudy Formation. The strata on the south east limb of the fold dip steeply to the south east and comprise Dungiven Formation and Mullaghcarn Formation. The Dungiven Formation is essentially limestone, with psammite, pelite and semipelite. Both the Claudy Formation and the Mullaghcarn Formation are described as mixed psammite, semipelite and pelite strata. These ancient rocks form the Sperrin Mountains and Bessy Bell which are located on either side of the Preferred Corridor and are Precambrian in age.
Between Victoria Bridge & Omagh, local faulting has left two outliers of younger Carboniferous age sandstone resting unconformably upon the older (dalradian) Sperrins strata described above;
• The Omagh sandstone & Claragh sandstone around Omagh,
• The Owenkillew sandstone between Victoria Bridge & Newtownstewart.
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2.3.4.3 Drift Geology
Glacial Soils The majority of the Section 2 Preferred Corridor is underlain by glacial deposits comprising Glacial Till, Glaciofluvial Sand & Gravel and mixed Hummocky Glacial Moraine6.
Within the northern part of the Section 2 area, from south of Strabane down to Ardstraw, the Preferred Corridor is predominantly underlain by Glacial Till deposits Glacial Till is essentially absent from Ardstraw down to the Newtownstewart area. From approximately 1km to the south of Newtownstewart, thin glacial till is shown to be present along the western part of the Preferred Corridor. From south of Mountjoy to the southern limits of Section 2, the Glacial Till deposits are widespread and form a series of stony clay drumlin mounds.
Glaciofluvial Sand & Gravel deposits are not as widespread as the Glacial Till. From Victoria Bridge, Sand & Gravel deposits are shown in the east of the Preferred Corridor, down to the River Derg. From the River Derg to Newtownstewart there are extensive sand & gravel deposits that are also widely extracted in the centre of the Preferred Corridor on the west side of the Strule River. From the Ulster-American Folk Park down through Killinure, Calkill to the Fairy Water, local pockets of Glaciofluvial Sand & Gravel are also recorded.
Undifferentiated glacial hummocky moraine deposits are recorded extensively in the Preferred Corridor from the area around the River Derg down past Newtownstewart. To the south of Newtownstewart the deposits are shown to be present in the eastern part of the Preferred Corridor down to the Ulster-American Folk Park.
Peat Deposits Low-lying areas of raised Peat Bogs have been recorded in the valley of the Fairy Water, close to its confluence with the Strule. Most notable of these is the Tully Bog SAC. Other smaller areas have been recorded in the northern part of the Preferred Corridor, one being approximately 1km to the south east of Victoria Bridge and the other close to the confluence of the Rivers Derg and Mourne/Strule.
In the southern part of the Preferred Corridor, from Mountjoy, to the Section 2 southern boundary are extensive areas of soft ground dominated by peat in the low- lying, poorly drained inter-drumlin areas. These are numerous, though not largely interconnected, though there are some larger areas of peat in the west of the corridor to the west of Omagh.
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Upland blanket Peat Bog is much less widespread in Section 2 and is only noted in 2 locations within the Preferred Corridor. One of the areas is on elevated, wooded land approximately 0.5km to the west of Victoria Bridge. The second area is located on the eastern facing slopes of Bessy Bell, in the western margin of the Preferred Corridor, close to Gortinagin.
Alluvial Soils The alluvial soils encountered in the Section 2 Preferred Corridor comprise River Alluvium and Lake Alluvium.
River Alluvium deposits are recorded along the banks of the major river courses located within the Preferred Corridor. These include the River Derg, Strule River, Coolaghy Burn, Owenkillew River, the Fairy Water, Gillygooly Burn and the Drumragh River. These deposits are typically between 30m and 1km wide, with the most extensive deposits being located in the Newtownstewart area. There is borehole evidence that these can be as much as 25m deep and largely consist of sand/gravel, though with pockets of soft peat and clay, especially in the upper 5m.
Lake Alluvium, which is expected to be largely soft clay, recorded in the area is generally found in discrete areas of low-lying land, close to water courses. Two of these areas are recorded in the northern part of the Section 2 Preferred Corridor, within 0.5km of Seein Bridge.
2.3.4.4 Man-made Features, Contaminated Land and Mineral and Mining Resources Contaminated Land Within the town of Newtownstewart, several potential contaminated land sources have been identified. There are 2 petrol filling stations, 1 timber treatment yard and a civic amenity centre for non-hazardous domestic waste within the town.
Mineral and Mining Resources Within Section 2 there are in excess of 30 old/disused small sand and gravel pits and quarries located within the Preferred Corridor. Although most of these pits and quarries have been backfilled, it is considered that the backfill is unknown & may be a potential source of contamination.
There are 2 large and 4 smaller active sand and gravel pits operating within the Section 2 Preferred Corridor including:
• Tony Harley & Son Ltd (Urbalreagh, approximately 300m south of the River Derg).
• Thomas Kane & Sons (Lower Deerpark).
• Thompons Quarry.
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2.3.5 Drainage and Hydrology The existing drainage and hydrological features within the Preferred Corridor are described in this section. Specific engineering constraints are outlined in conjunction with information relating to flooding considerations.
Preliminary hydrological assessments have been made in order to ascertain the principal rivers and associated drainage basins within the A5 WTC Preferred Corridor. The main drainage basins are shown in Figure 2-23.
Figure 2-23: Principal A5 WTC Drainage Basins The principal watercourse in the study area is the Mourne/Strule River which flows in a south to north direction from Omagh to Strabane via Newtownstewart, Victoria Bridge and Sion Mills.
The Strule River is formed when the Camowen and Drumragh Rivers converge at Drumragh Bridge in Omagh. The Strule River then flows for approximately 26km in a northerly direction towards Strabane until it converges with the River Derg at Bunderg to form the Mourne River (4km north-west of Newtownstewart). The Mourne River then flows 14km towards Strabane where it converges with the Finn River to form the River Foyle.
The Strule River incorporates a number of designated watercourses as well as numerous undesignated watercourses as it flows towards Strabane. Its principal tributaries include the Fairywater which discharges into the river at the Beltany Road in Omagh and collects water from the largely rural catchment area to the west of
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Omagh, and the Owenkillew River at Newtownstewart which collects water from a predominantly rural upland catchment area to the east of Newtownstewart. The Owenkillew River catchment also incorporates the small urban catchments of Plumbridge and Gortin.
Through discussions with Roads Service Maintenance Section Offices and Rivers Agency, it is known that sections of the existing A5 within Section 2 have been prone to historical flooding or effected by flood debris.
• A5 at the Fairywater – is liable to flooding.
• A section of the A5 north of Mountjoy experiences localised flooding with the free passage of surface water across the road surface as it discharges from the adjacent slope during exceptional rainfall.
• Junction at Victoria Bridge has exhibited localised flooding. The existing watercourse culvert has been enlarged to mitigate against future occurrences.
It is observed that there is a narrow floodplain, approximately 150m wide, along the length of the Mourne – Strule Extension. At the confluence with key tributaries these floodplains are more extensive.
Where the River Derg converges with the Mourne-Strule Extension the floodplain is approximately 500m wide. The River Derg Floodplain is crossed perpendicularly at Ardstraw. There is also an extensive floodplain in the local of Newtownstewart associated with the convergence of the Owenkillew River and the Mourne – Strule Extension. The floodplain adjacent to Newtownstewart varies in width to a maximum of approximately 800m wide.
Within the Preferred Corridor to the west of Omagh there is an extensive floodplain associated with the confluence of the Fairywater River, including the Fairywater tributaries of Tully Drain, Rush Drain, Gillygooly and Coneywarren Drain. It is identified that the floodplain associated with this network of watercourses is approximately 1.2 km in width.
Immediately south of Omagh the Drumragh River floodplain runs parallel to the watercourse and is approximately 200m wide.
2.3.6 Existing Structures Conditions This section of the document deals with the assessment of the condition of the existing structures, recommendations on any remedial works required and comments on the options for widening each structure in Section 2. For those sections of the existing route where there are significant constraints to widening the route, such observations are made. The structures described in this section are those that remain within the Preferred Corridor.
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2.3.6.1 Summary of Route There are 14 significant bridges having spans greater than 1.8m in Section 2 and 3 of them are considered to be major crossings with cumulative spans of over 40m.
The majority of the bridges on the route carry the A5 over watercourses with only 1 road over road bridges. This is typical of routes in such landscapes where most junctions are at grade. Generally the structures are not very large with a median span of 4.1m but with a maximum span of 118.9m.
Table 2-9: Bridges by Function and Section
Function Section 2
Footbridge Over Road - Road Over Accommodation - Road Over Pedestrian Subway 1 Road Over Road 1 Road Over Watercourse 12 Grand Total 14
As indicated in Table 2-9 above, there are a total of 14 significant bridges (i.e. > 1.8m span) on the route. Additionally, there are 4 retaining walls over 1m high which either support the road or retain landscape and/or structures adjacent to the road. The vast majority of these structures are in fair to very good condition and, when considered in isolation, most could be modified for use in a scenario where the existing A5 was widened to dual carriageway, if required. There are also a number of smaller structures (less than 1.8m span) along the route although these were not thoroughly inspected and no condition ratings were assigned.
2.3.6.2 Structure Types Of the significant bridges, there are a wide variety of construction types, with some of mixed construction where the structure has been widened.
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Table 2-10: Significant Structures by Road Section
Structure Type Sections 2
Composite Concrete & Steel 2 Concrete Arch/Masonry Arch - Concrete Box Culvert 2 Corrugated Steel Pipe - Half Joints - Masonry Arch 3 Masonry Arch/RC Slab 1 Prestressed Concrete Beams 1 RC Pipe 1 RC Slab 2 RC Slab/RC Pipe 2 Steel Truss/Steel Plate - Grand Total 14
In addition, there are a number of small culverts (less than 1.8m) whose construction was often unclear as they were submerged or otherwise hidden.
Four retaining walls (>1m high) were identified along the route where failure may impact on the efficacy of the carriageway. There does not appear to be a register of retaining walls for this route and therefore not all of the walls which were recorded in the survey may be in public ownership. However, they are included as they should be monitored as part of an asset management programme and they will need to be addressed as part of any proposed A5 widening scheme. For convenience, these walls have been split into four arbitrary height bands:
• Small – less than 3m;
• Medium – 3 to 5m;
• Large – 5 to 9m;
• Very Large – Over 9m.
• Very few construction details were available for inspection for any of the major structures and none for the minor structures or the retaining walls. An assessment of the basic construction type is included in the national database and this has been used as a basis for this study. For the minor structures and retaining walls, no attempt has been made to classify the construction type.
The following tables indicate the size, type and general condition of the structures. As can be seen, the structures are of mixed size and construction type but are
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generally in good condition throughout. Some relatively minor defects are present and the key information about each structure is presented below.
Table 2-11: Section 2 Structures – Construction Types and Size
NIRS Structure No of Span Width No Structure Name Structure Type Spans (m) (m)
60662 Unnamed RC Slab/RC Pipe 1 2.45 34.80 60661 Unnamed RC Slab 1 4.9 34.80 61433 Derg River Bridge Half Joints 3 44.8 17.05 62406 Pubble Bridge Composite Concrete & Steel 3 118.9 13.60 Newtownstewart Pedestrian 62409 Underpass Concrete Box Culvert 1 4 23.36 62407 Croshballinree Bridge Composite Concrete & Steel 3 92.35 13.20 62408 Grange Bridge Concrete Box Culvert 1 9.7 27.00 60660 Unnamed RC Slab 1 2.17 24.50 61208 Beltany Bridge Masonry Arch/RC Slab 1 3.62 16.20 61211 Unnamed RC Pipe 1 1.2 17.00 61819 Unnamed Masonry Arch/RC Slab 1 1.85 18.00 61209 Unnamed Masonry Arch/RC Slab 1 2.3 18.00 60878 Unnamed Masonry Arch 1 1.94 13.10 61143 Poe Bridge Masonry Arch 2 20.76 13.20
Table 2-12: Section 2 Structures – Condition Ratings [Scores are based on draft Highways Agency standard performance measurement of highway structures (PMHS)]
NIRS Structure No Structure Name Average Condition Rating
60662 Unnamed Good 60661 Unnamed Good 61433 Derg River Bridge Fair 62406 Pubble Bridge Very Good Newtownstewart Pedestrian 62409 Underpass Very Good 62407 Croshballinree Bridge Very Good 62408 Grange Bridge Very Good 60660 Unnamed Fair 61208 Beltany Bridge Good 61211 Unnamed Fair 61819 Unnamed Very Good 61209 Unnamed Good 60878 Unnamed Fair 61143 Poe Bridge Fair
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Retaining Walls
Table 2-13: Section 2 Retaining Walls – Size, Function and Condition [Scores are based on draft Highways Agency standard performance measurement of highway structures (PMHS)]
Mouchel Wall Length Wall Height Overall Structure No (m) (m) Function Assessment
S16 47 1.15 Supports an Embankment Very Good S17 59 1.4 Supports Residential land Poor S21 35 4 Supports Strabane Road Very Good OM2A 24 3 Supports the A5 Very Good
2.3.6.3 Widening Issues Approximately a quarter of the structures in Section 2 would be difficult to widen on line. Typically, the structure itself could be widened but there are existing constraints adjacent to it.
About half of the structures could readily be widened on line, if required, although this would be considered further as the design is developed through Stage 3.
Of the remaining structures, it is considered that it would be more economical to completely replace 2 no, should they be required to accommodate a widened A5.
It is considered that the 2 relatively new bridges on the Newtownstewart bypass would best be widened by constructing a new bridge parallel to the existing.
2.3.6.4 Structural Capacity The assessed capacity of the structures is reported in the NIRS database although the records were not complete at the time of inspection.
Eight bridges have been assessed as having 40 Tonne HA loading capacity and are rated at 45 units of HB loading. The remaining 6 structures have no HB rating.
2.3.7 Existing Pavement Conditions 2.3.7.1 Deflectograph From this analysis it was found that approximately 49% of Section 2 has a residual life of less than 5 yrs, 32% is between 5 and 20 years, and 18% has a residual life greater than or equal to 20years. Approximately 1% of the road has no data available.
2.3.7.2 Visual Assessment using Digital Video Survey The data represented in this section applies to the entire length of the existing A5 within Section 2. Approximately 48% of northbound and 45% of southbound carriageways are considered to be showing signs of physical deterioration. No rutting is apparent in either direction. The northbound carriageway has the highest
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concentration of “two-wheel path” cracks while the southbound shows more “one- wheel path” cracks.
The visual survey method used replicates that of a UKPMS visual survey. Therefore, the result of the visual assessment was analysed similar to a UKPMS automatic pass. This process involves all the defects collected being analysed to produce constant defective lengths, which are then given a defect rating. This defect rating is in turn analysed to produce a condition index, i.e. structural or wearing course. The data was then further processed through bespoke scheme analysis software which utilises the condition index values to produce realistic scheme lengths. Therefore the defects recorded from the DV were broken down into condition indices and treatment options.
2.3.8 Baseline Environment 2.3.8.1 Air Quality There is one Air Quality Management Area (AQMA) within Newtownstewart. The declaration relates to historic coal fire burning.
Data for current concentrations related to the two traffic-based pollutants (nitrogen
dioxide (NO2) and particulate matter (PM10) within this section of the Preferred Corridor indicates that existing levels are well within statutory thresholds defined to protect human-heath (40 µg/m3 for both pollutants).
In relation to NO2, initial diffusion-tube data collected at key roadside locations indicates a range of concentrations between 3.7 – 30.3 µg/m3, the former being related to Letterbin Road (Grid Ref 234248, 382881) and the latter to Campsie Road (Grid Ref 245824. 372794).
In relation to PM10, there is no monitoring data available for locations within the section including the AQMA. The section is, however, one within which settlement and traffic contributing to concentrations of the pollutant are less densely populated and less heavily trafficked than for Section 1. Taking into account the data obtained from the AQMA in Strabane and the lesser scale of potential contributing sources throughout this section, it can be reasonably concluded that concentrations within the section will be lower than those identified at Strabane and that they are, accordingly, well within the statutory threshold levels.
Receptors considered to be sensitive to changes in air quality are mostly concentrated within the main settlements of Sion Mills / Glebe, Newtownstewart, and Omagh. Their location in relation to the Preferred Corridor and distribution of more dispersed receptors in the form of dispersed hamlets and individual properties is shown in drawings 796036-3000-D-25124 and 25125. Taking into account the full extent of the Preferred Corridor and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 9631 existing receptors who could be subject to increases or decreases in concentrations of the two pollutants. These
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include 9586 residential properties, 29 schools, 12 medical facilities and 4 residential care homes.
Preliminary calculations for regional emissions associated with traffic using the identified network within the section indicate total emissions of nitrous oxides (NOx)
in the order of 235 tonnes/annum. Equivalent figures for PM10 and Carbon (C) are 6 and 18,695 tonnes/annum respectively.
2.3.8.2 Cultural Heritage Archaeology The review of baseline data and information derived from field walkover surveys has established the presence or potential presence of 258 sites or monuments within this section. The location of each is shown in drawings 796036-3000-D-24014 and 796036-3000-D-24015.
There are 8 scheduled monuments and 55 known monuments of medium/low value. There are 86 industrial heritage sites of low value and 107 potential new sites located during the field walkover survey. The latter are of unknown value.
The known sites and monuments comprise megalithic tombs, raths, religious buildings, castles and industrial heritage sites. The latter are represented by ruins, and derelict or disused buildings and structures including bridges, railways, and mills (most of these are flax mills associated with the historic linen trade within the area).
There are megalithic burial tombs of Neolithic and early Bronze Age located on the lower eastern slopes of Bessy Bell and on localised high points like drumlins in the southern part of the section. There is no known evidence for the settlements of the people buried in these tombs. Therefore, there is high potential for the discovery of prehistoric settlement within the Preferred Corridor in this area.
Raths in this section are located along the edge of ridgelines, or at the summits (or close to the summits) of drumlins. There is a notable concentration of rath sites to the east of Bessy Bell and to the south of Omagh.
A key interest within the section relates to sites and features associated with Newtownstewart. The castle at Newtownstewart is located at the end of the main street. Northeast of the town there is the site of a Franciscan Friary, now in use as Pubble Graveyard.To the west of the town, Harry Avery’s castle (a Scheduled Monument) is located on high ground overlooking the surrounding landscape. Surrounding this castle are a number of other features suggesting an area of archaeological potential.
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Figure 2-24: Harry Avery’s Castle Built Heritage There are 28 listed buildings, 1 Conservation Area (at Newtownstewart) and 14 Industrial Heritage Sites in this section. There are also 29 non-designated built heritage assets which the field survey team has identified during initial walkover surveys. The location of each is shown in drawings 796036-3000-D-24014 and 796036-3000-D-24015.
Twenty-one of the listed buildings are located within Newtownstewart, 19 of those within the Conservation Area. The remainder of the recorded and non-designated assets are dispersed throughout the section.
Twenty-seven of the listed buildings are listed as Grade B/B1/B2, such that they are of regional importance and have a medium value. One structure, Newtownstewart Bridge, is listed at B+, a grading which recognises the structure’s national importance.
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Figure 2-25: Newtownstewart Bridge All of the 14 industrial heritage sites are low in value. The 29 non-designated assets are largely vernacular buildings of a low value. One, Rash House is of low/medium value due to its architectural interest.
Historic Landscape Characterisation The baseline survey has concluded that there is one area where the combination of landform, land use pattern, field pattern, settlement and complexes of archaeological/built form within the landscape warrant consideration in terms of their cultural/historic sensitivity. This relates to the valley, and hills in the vicinity of Newtownstewart and the town’s relationship to them.
2.3.8.3 Landscape There is a marked contrast in the landscape associated with the northern and middle thirds of this section of the corridor and the southern third of the corridor. The northern and middle thirds are closely contained within the moderately incised valley of the Mourne River and the more deeply incised valley of the Strule River south of Newtownstewart. By comparison, the southern section is relatively open as it crosses a gently undulating area associated with the confluence of the Strule River and Fairy Water and the wide Fairy Water valley as it runs to the west.
Between Sion Mills/Glebe and Newtownstewart the river meanders through a valley framed to the west by a series of rounded foothills that mark the western margins of the Sperrins AONB. The relationship of the AONB to the Preferred Corridor in this location is shown in Figures 796036-3000-D-21015 and 796036-3000-D-21016. Beyond the foothills, the profiles of Conthem Hill and Meenashesk Hill mark the skyline. The lower valley slopes are sparsely settled, the one notable settlement being Douglas Bridge located on the Douglas Burn as it descends from the Sperrins.
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The western valley side is defined by hills similar in form and scale to those east of the river, the most prominent being Glentimon Hill and Clady Hill. The valley slopes are moderately steep. The settlements of Sion Mills and Victoria Bridge occupy locations on the flatter margins alongside the river, whilst Glebe is located west of Sion Mills in an area where the mid slopes are relatively gentle. At the confluence with the River Derg there are views along the valley to the west towards Ardstraw.
There is a significant node in the landscape in this part of the corridor, at Newtownstewart. The town sits to the west of the Strule River on slopes rising above a distinctive meander in the river which also marks its confluence with the Owenkillew River. The northern slopes of Bessy Bell provide an imposing backdrop to the town to the south west. It is a composition which is well appreciated from the existing A5 as it crosses the meander in the river and bypasses the town to the north and east. It is also a composition which can be viewed from parts of the foothills and western Sperrins north of the River Strule. A windfarm located near to the elongated crest of Bessy Bell is a distinctive feature in some of these more distant views. Harry Avery’s Castle set on the lower slopes to the west of the town can also be picked out in these distant elevated views across the corridor.
Figure 2-26: The existing A5 at the foot of Bessy Bell South of Newtownstewart, the valley is deeply incised. Views from the existing A5 are strongly focused along the valley as the road runs close to the western margin of the river. Bessy Bell rises sharply to the west. Mary Gray and Deers Leap appear prominently to the east. The Preferred Corridor extends from the river west across the existing road corridor and across the lower and mid slopes of Bessie Bell. The more elevated parts of the corridor are open to view from the hills east of the river and appear in views from a complex network of local roads east of the river that extends as far as the Gortin Glen Forest Park.
As the corridor emerges from the incised valley, the landscape and the Preferred Corridor open out. There is an initial tract of undulating landform which gives way to
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the broad floodplain of the Fairy Water. At the western margins of the corridor there are substantial blocks of woodland which frame a distinctive local area in the context of the open valley landscape. South of the floodplain and west of Omagh there is a locally elevated area of drumlins. Stands of tree planting and boundary hedges combine with the intricate landform to frame an area composed of a series of intimate cells through which a complex network of local roads is threaded. It is a pattern which extends throughout the corridor to the south of the town as the drumlin landform continues, albeit at a generally lower elevation than the area to the west.
Landscape Character Areas and Landscape Character Zones Four of the sub-regional landscape character areas identified in the Northern Ireland Landscape Character Assessment are associated with this section of the Preferred Corridor: Sperrin Mountains (character reference No.29), Derg Valley (character reference No. 20) Bessy Bell and Gortin (character reference No. 26) and Fairy Water (character reference No. 21). The extent of the character areas is shown in Figures 796036-3000-D-21015 and 796036-3000-D-21016.
At a more detailed level the assessment team has identified 14 Local Landscape Character Zones (LCZs). These are shown in Figures 796036-3000-D-21015 and 796036-3000-D-21016. Of these, 7 have been identified as being of good quality and high landscape value, such that they would be the more sensitive of the areas to the introduction of the proposed dual carriageway. 3 have been identified as having a low capacity to accept change allowing for the consideration of the potential to mitigate likely impacts. These 3 are:
• Meenashesk Highland Bogs and Forest
• Owenkillew Valley & Plateau Bogs
• Bessy Bell Hill Mass
Visual Receptors The following residential receptors have been identified:
• a number of properties in and around the villages of Sion Mills and Glebe;
• scattered properties that occupy the eastern slopes of the River Mourne valley to the east of the existing A5 extending to the south as far as Newtownstewart;
• properties in and around the village of Victoria Bridge, including a number that occupy a gently rising landform to the west;
• properties within Newtownstewart, in particular those to the east of the Town that are afforded open views of the river valley and existing A5 , and properties to the west with views of the surrounding hill slopes;
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• a number of properties within the village of Mountjoy and the surrounding areas;
• a number of properties that occupy locations adjacent to the existing A5 to the north of Omagh;
• a small number of residential streets to the west of Omagh that are afforded views of the open countryside to the west; and
• scattered properties that occupy extensive areas of open countryside to the west and south west of Omagh.
In addition, there are views from sections of National Cycle Network Route 92 where it passes through Omagh and follows the B48 and unclassified roads immediately east of the Rivers Strule & Mourne as far north as Strabane and Route 95. From here it extends west from Castlederg to cross the existing A5 at Newtownstewart and link with route 92 before continuing eastwards in the direction of Gortin.
Parts of two Scenic Driving Routes promoted by Sperrins Tourism include roads and local lanes within the section. The existing A5 between Sion Mills and Newtownstewart and the B46 between Newtownstewart and Gortin form part of the Central Sperrins Scenic Route. The parts of the route within this section are shown In drawing 796036-3000-D-21015. The following form part of the Southern Sperrins Scenic Driving Route.
• the A32 running south west of Omagh,
• a local road, Castletown Road running south from Newtownstewart linking with the A5 as far as Mountjoy and
• a local lane that runs along the mid southern slopes of the Owenkillew Valley as far as Gortin
2.3.8.4 Nature Conservation Statutory Designated Sites Designated sites located within or in close proximity to the section are indicated in drawings 796036-3000-D-23184 and 796036-3000-D-23185 and are scheduled below with an outline of the interests associated with them.
• The River Foyle and Tributaries Special Area of Conservation (SAC) and Area of Special Scientific Interest (ASSI) - a plain to montane level watercourse noted for the presence of water-crowfoots and water-starwort and significant populations of Atlantic salmon and otter.
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• Owenkillew River (SAC) and (ASSI) – watercourse of plain to montane levels noted for the presence of water-crowfoots and water-starwort / old sessile oak woods with Ilex and Blechnum/freshwater pearl mussel. Qualifying features: bog woodland, Atlantic salmon and otter.
• Tully Bog (SAC) and (ASSI) – primary raised bog
• Grange Wood ASSI – woodland flora and associated fauna.
The three SACs are of international importance. The ASSIs are of national importance.
Figure 2-27: Grange Wood Non-Statutory Designated Sites There is one non-statutorily designated site associated with this section. This comprises Cottage Farm, an Ulster Wildlife Trust Nature Reserve located north of Mountjoy and east of the Strule River. The site supports woodland, wetland and bog with a diverse faunal and floral assemblage. The site has been assessed as being of likely biodiversity value at the county level due to its potential for locally important species and high potential for amenity use as the only Wildlife Trust Site in Tyrone.
Classified Watercourses There are five watercourses classified under the EU Water Framework Directive (WFD) and which are classified as Salmonid Waters under the EEC Freshwater Fish Directive within the section. These comprise the River Derg, Strule River, Owenkillew River, Fairy Water and Drumragh River. All contain habitats considered highly suitable for spawning by Atlantic salmon.
Habitats The more significant areas of habitat within the section are outlined below and shown in drawings 796036-3000-D-23184 and 796036-3000-D-23185.
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Woodland and Hedgerows
Significant examples of woodland in addition to Grange Wood include:
• woodland adjacent to the River Mourne – up to national biodiversity value (Eco ID Area 580b / various);
• woodland adjacent to the River Strule – County biodiversity value (Eco ID Area 252b / various);
• Mountjoy Forest – County biodiversity value (Eco ID Area 652/H438764);
• Woodland along the Gillygooly Burn and on surrounding hills - County biodiversity value (Eco ID Area 89 / H407734); and
• Newtownstewart riverbank - County biodiversity value (Eco ID Area 580/H406856).
There are some areas of fragmented ancient woodland which have been assessed as being of value at a district level.
In common with hedgerows within Section 1, those in this section are an important biodiversity resource in relation to flora and fauna.
Peatland
Significant examples of peatlands in addition to the internationally designated Tully Bog, are located at Aghee and Bessy Bell. The former is an active secondary bog and bog woodland of county value. The latter is an active secondary bog and wet heath which is also of county/district value.
Watercourses and Waterbodies
Significant examples of habitats associated with watercourses, in addition to the designated SACs and ASSIs, are located along reaches of the Fairy Water, the Gillygooly Burn and Kilmore Burn. Those associated with the Fairy Water are of county value whilst those associated with the other two watercourses are of county/district value.
Significant examples of habitats associated with waterbodies include a pond at Tully Bog and three ponds located at Mountjoy Forest. The Tully Bog pond is noted in the ASSI citation and is of international value. The Mountjoy ponds are of county value.
Fauna Invertebrates
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The surveys have identified 23 specific areas within the section where it has been concluded that habitats have the potential to support priority species and species of conservation concern (SOCC). The areas of high potential are shown in drawings 796036-3000-D-23190 and 796036-3000-D-23191.
Freshwater pearl mussels, which are listed under Annexes II and V of the Habitats Directive, have been found within the Mourne River, River Derg, Drumragh River and Owenkillew River within the section, mostly within deeper reaches of the rivers.
Fish
There are records of Atlantic salmon and brown trout for the River Derg, Owenkillew River and Drumragh River. Habitat surveys undertaken by the Loughs Agency for the Foyle catchment have also identified a number of important holding, nursery and spawning habitats of relevance to this section of the Preferred Corridor. These comprise:
• The Glenelly catchment, (incorporating the confluence between the Owenkillew River and the Strule River) - important for salmonid spawning.
• One small area of habitat, between the current A5 and the confluence with the Owenkillew River - important for salmonid spawning.
• The Fairy Water catchment (covering Gillygooly Burn and Kilmore tributaries) - important for nursery and some spawning potential.
• The Strule catchment - nursery habitat and presence of holding pools to aid migration.
Other species recorded include gudgeon, roach, stone loach, 3-spined stickleback and eel.
Birds
In common with Section 1, records relating to breeding birds within the section indicate that the area supports small to moderate populations of generally common species and a small number of less common species, though the field surveys noted areas of habitat which are of potential value for a larger number of species than are currently recorded. Two areas of particular potential were noted; one south of Mountjoy and one south west of Omagh and north of Cavanacar Bridge.
Otters
Otters are a qualifying feature of the Foyle and Tributaries SAC and are assumed to be present in high numbers in all watercourses within the section. Site surveys have identified some twenty-one potential breeding sites. These are indicated in drawings 796036-3000-D-23190 and 796036-3000-D-23191.
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Bats
There are a number of locations within the section where bat roosts have been identified and habitat types have been identified as being of biodiversity value in relation to bats (drawings 796036-3000-D-23190 and 796036-3000-D-23191). The most significant include:
• a number of areas of long-established semi-natural woodland, including Grange Wood ASSI, Mountjoy Forest and woodlands associated with Baronscourt;
• scrub areas associated with Grange Wood ASSI and the disused railway in the Strule Valley; and
• the riverine habitats associated with the Mourne River, Strule River (part of the Foyle River and tributaries SAC) and the River Derg.
2.3.8.5 Materials The solid and drift geology within the section are described in the geotechnical section of this chapter, paragraphs 2.3.4.2 and 2.3.4.3 respectively.
The dominant soil types are Brown Earth and Gleys. They are primarily classified as being of good and moderate agricultural potential (Grades 3a and 3b). The exceptions are where soils associated with steep slopes in the west are generally of Grade 4 potential and where there are sands and gravel in the valley bottoms and soils are generally of Grade 2 potential.
There are no statutorily designated sites of geological value within the section. There are, however, two areas which are recognised as having geological value. These comprise Deer Park Moraine and Outwash and the Strule Valley which is part of the Foyle Valley Complex.
There are no extensive areas of contaminated land within the section.
2.3.8.6 Noise In common with Section 1, the principal dominant continuous noise source within this section relates to traffic using the local road network with the busiest road being the A5. Preliminary LA10 measurements taken at the immediate roadside indicate existing traffic-related noise levels in excess of 74.5dBA. With increasing distance from the A5 levels will be noticeably lower as will levels associated with local roads within the section and throughout the rural areas that substantially constitute the Preferred Corridor.
Receptors considered to be sensitive to changes in traffic-related noise are mostly concentrated within the main settlements of Glebe, Sion Mills, Newtownstewart, and Omagh. Their location in relation to the Preferred Corridor and distribution of more
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dispersed receptors in the form of hamlets and individual properties is shown in drawings 796036-3000-D-25124 and 25125.
Taking into account the full extent of the Preferred Corridor, and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 16622 existing receptors who could be subject to increases or decreases in traffic related noise. These include 403 non-residential receptors including places of worship, rights of way and open spaces, and community facilities.
Site observations indicate that there are no continuous major sources of airborne vibration within the Preferred Corridor.
2.3.8.7 Effects on all Travellers Rights of way in the form of cycleways and footpaths within the section which could be potentially subject to discruption of loss of amenity value depending on proximity to or severance by any of the proposed alternatives are shown in drawings 796036- 3000-D-22114 and 796036-3000-D-22115 and are scheduled below.
• National Cycle Route 95 - Newtownstewart to Cookstown and Republic of Ireland.
• The North West Trail - Lifford, Strabane and Omagh.
• Sperrins Route 6 Derg Valley Cycle Route - Sion Mills, Douglas Bridge, Newtownstewart, and Castle Derg
• Sperrins Route 3 The Strule Valley Cycle Route - Sion Mills, Douglas Bridge, Newtownstewart, Gortin and Plumbridge.
• Belfast to Ballyshannon Cycle Route - Omagh to Belfast and Republic of Ireland.
• Newtownstewart to Strabane Cycle Way - Newtownstewart, Douglas Bridge, Sion Mills and Strabane.
• The Ulster Way (footpath and bridleway) - the route crosses the Preferred Corridor between Mountjoy and Newtownstewart.
2.3.8.8 Community and Private Assets Population, Community Facilities and Access The distribution of existing facilities in the form of shops, schools, churches, libraries hospitals, sports and recreational facilities and rights of way providing for access to the countryside is shown in drawings 796036-3000-D-22114 and 796036-3000-D- 22115.
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The largest settlement associated with this section is Omagh, the County Town of County Tyrone. The town is located in close proximity to the eastern margin of the corridor. It is the administrative, commercial and retail focus of the wider area within which the Preferred Corridor is located. It is also the main location for essential communal and social facilities including schools and cultural venues, hospital and medical services, leisure and entertainment facilities. The town is at the hub of key radial routes, including the existing A5 which afford access from the immediate hinterland and wider strategic links from further afield.
There are three other towns of note within or in close proximity to the corridor; Sion Mills, Castlederg and Newtownstewart. Outside of these, settlement within the contained valleys of the River Mourne and River Strule as far as the south of Bessy Bell is limited to sparsely scattered properties on the lower and middle valley slopes. South of Bessy Bell and west of Omagh, there is a greater density of dispersed hamlets and individual properties. Notable hamlets include, Mountjoy and Gillygooly.
At the northern end of the section, the relationship between Glebe and Sion Mills is an important one, Glebe being largely dependant on the communal facilities and shops within Sion Mills.
Private Assets The dominant land use is agriculture, with most of the area being classed as Best and Most Versatile (BMV) land (Grades 3A/2/1). The extent of BMV land in the section is shown in drawings 796036-3000-D-22137 and 796036-3000-D-22138.
Between Sion Mills and Mountjoy the land is predominantly Grade 3A with occasional pockets of Grade 2 north of Victoria Bridge and south of Douglas Bridge. South of Mountjoy, to the juncture with Section 3, there is a mosaic of Grade 2, 3A and lower grade land in which the two higher grades are of similar extent.
Between Sion Mills and Mountjoy there are groupings of dairy farms south of Sion Mills, east of Victoria Bridge, north of the river Derg, north west of Newtownstewart and on the east slopes of Bessy Bell. South of Mountjoy there are a significant number of dairy farms, there being a significant concentration around Gillygooly and the Fairy Water Valley.
The locations of planning approvals granted during the last three years are shown in drawings 796036-3000-D-22143 and 796036-3000-D-22144. Applications of specific note in relation to the alternatives comprise a cluster of applications on the north western fringe of Newtownstewart. Cognisance was also given to the Opportunity Omagh proposals.
Drawings 796036-3000-D-22131 and 796036-3000-D-22132 show the development limits for Sion Mills, Glebe, Victoria Bridge, Newtownstewart, Mountjoy and Gillygooly.
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2.3.8.9 Road Drainage and the Water Environment Surface Water This section of the Preferred Corridor is located within the mid and upper catchment of the River Foyle. The principal watercourses comprise the Drumragh River, Strule River, River Mourne, Fairy Water, Owenkillew River and River Derg. The watercourses and extent of existing floodplains associated with the watercourses are shown in Figures 796036-3000-D-27098 and 796036-3000-D-27099 and described in (Paragraph 2.3.5).
All of the watercourses have been classified as moderate to very good for chemical water quality and moderate to good for their biological water quality.
Due to the relatively impermeable nature of the underlying geology and soils, these rivers have high peak flows and rapid response rates during heavy rainfall events and low flows during prolonged periods of dry weather.
Historically, the settlements of Ardstraw, Newtownstewart and Omagh have all experienced extensive flooding from the River Derg, Strule River and Fairy Water respectively. The floodplain areas for the Derg and Strule are generally well confined by narrow steep sided valleys. The Fairy Water floodplain is more extensive.
Groundwater There is little or no groundwater potential within the northern half of the section due to the impermeable nature of the underlying bedrock. The southern half is primarily underlain by moderately permeable bedrock with limited or local potential as an aquifer. Other than in areas of alluvium or sand and gravel deposits permeability of the soils is low and groundwater vulnerability is correspondingly low. The areas of alluvium and sand and gravel have a high leaching potential and correspondingly higher vulnerability.
Those aquifers found in the section have been classified under the WFD as being of ‘Good’ status for both chemical quality and water quantity.
Peatlands There are numerous and, sometimes, extensive areas of peat in the southern third of the section as the corridor emerges from the contained Strule Valley below Bessy Bell and passes west of Omagh to its juncture with Section 3. One comprises the designated Tully Bog SAC & ASSI. The bog is a lowland raised peat bog fed entirely by rainwater.
The periphery of all of the bogs have been extensively cut and drained resulting in depressed water levels and associated deterioration in the condition of the bogs.
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Water Abstraction and Discharges There are no existing public water abstraction points within the section. There are, however, 6 surface water and 10 groundwater abstractions. These are for commercial, agricultural and/or private drinking supplies. Two relate to quarrying activity and 4 to commercial salmon hatcheries. There is also a proposal for a public drinking water abstraction on the River Strule, downstream of Newtownstewart. There are 8 licensed discharge consents and 6 sewage treatment plants. The location of these various abstractions and discharges is shown in Figures 796036- 3000-D-27098 and 796036-3000-D-27099.
2.3.9 Existing Traffic Conditions It should be noted that, while lengths of the existing A5 in Section 2 are located outside the Preferred Corridor, traffic conditions on the various links of the existing road network are inextricably linked and are therefore described in this section.
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2.3.9.1 Traffic Flows
Figure 2-28: Traffic flows in vicinity of Section 2 of the scheme during May 2008 (daily Monday to Thursday average, excluding bank holidays)
Figure 2-28 shows typical traffic flows in Section 2 of the A5 WTC scheme. These values are 24 hour weekday vehicle flows (Monday to Thursday). The figures show that the road with the highest flow in this area is the A5, with a 24 hour flow between about 12,200 and 15,020 vehicles per day.
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Detailed traffic analyses are presented for the location shown by the green triangle on Figure 2-28. This location is on the A5 immediately to the north of Derry Road roundabout, just to the north of Omagh. These analyses are presented in Figure B-4 to Figure B-7 inclusive, within Appendix B.
Figure B-4 displays the monthly average daily flows at the long-term ATC at NIRS site 626. This site is used to represent traffic conditions in Section 2 of the scheme and is coincident with the green triangle shown on Figure 2-28.
The values for May 2008 are somewhat higher than values for most other months, at around 14,000 vehicles per day. The average daily flows for all months are between 12,000 and 15,000 vehicles.
The daily flow profile in May 2008 at this location is shown on Figure B-5. This figure indicates that the principal movement of traffic is southbound in the morning peak (towards the centre of Omagh), between 8am and 9am, and northbound in the afternoon peak (away from the centre of Omagh), between 5pm and 6pm. The maximum hourly flow is about 800 vehicles per hour in the dominant direction.
The daily flow profile in May 2008 indicates very prominent peak flows, especially in the morning peak, when the southbound flow is nearly twice that of the northbound flow. In the afternoon peak the northbound flow is more than 50% greater than the southbound flow. This pattern of traffic is consistent with the site’s proximity to Omagh, with commuters being attracted to the town.
Figure B-6 shows the distribution of vehicle types through a single day MCC survey on Tuesday 29 April 2008 at the location of the green triangle shown on Figure 2-28. These analyses indicate a high proportion of car journeys through Section 2. This traffic also comprises a significant proportion of journeys by LGV throughout the day. The LGV and HGV proportions are approximately equal to one another during the interpeak period. During the morning and afternoon peaks the LGV proportion is about 50% greater than the proportion of HGVs. This may suggest the use of LGV vehicles for some home to work trips.
The proportions of motorcycles, buses and coaches are very small.
An assessment of the daily flow profile of traffic on the A5 on the Omagh throughpass in central Omagh is shown as Figure B-7. This is assessed at NIRS long-term ATC site 645, between the intersections of the A5 with the A32 and with Kevlin Road.
This urban location experiences greater traffic flow than the more “rural” length to the north of Omagh assessed in Figure B-5. Peak flows occur at this location in both the morning and the afternoon in both directions. The period between the morning and afternoon peak can be seen to experience flows of at least 70% of the peak values, indicating little easing of the traffic volume throughout the day, typical of an urban location.
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Traffic flow on the A5 in the southbound direction is consistently greater across the day than in the northbound direction. This may be explained by the presence of several one-way streets in the town centre near to this location. Traffic movements in the northbound direction are permitted along these streets, but certain southbound movements are restricted. This restricted southbound traffic may therefore divert onto the A5 thus increasing the southbound flow on the Throughpass.
Turning movement flows through various significant junctions along the A5 in Section 2 are shown in Figure 2-29 to Figure 2-31 inclusive. These are shown as 12 hour vehicle flows between 7am and 7pm on Tuesday 29 April 2008.
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Figure 2-29: 12 hour Vehicle Flows at junction of the A5 with the B48 and B50 to north of Omagh on Tuesday 29 April 2008 The traffic flows shown in Figure 2-29 are for the A5/B50/B48 junction known as the Derry Road Roundabout, north of Omagh. This shows that the main movement of traffic at this junction is between the two arms of the A5 as expected. There are substantial volumes of traffic turning between the B48 and both the A5 arms, and also between the B50 and the southern arm for the A5, though not between the B50 and the A5 to the north.
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Figure 2-30: 12 hour Vehicle Flows at junction of the A5 with the A32 in Omagh on Tuesday 29 April 2008 Figure 2-30 shows the traffic flows at the junction of the A5 with the A32 and Tamlaght Rd, along the A5 Throughpass in Omagh. There is a considerable amount of traffic turning from the southbound A5 onto Railway Link Road and onto the southbound A5 from the Railway Link Road. Railway Link Road provides access from the A5 to the A32 (for Enniskillen), and is also a route used by traffic accessing Omagh town centre.
The traffic flows between the Railway Link Road and the A5 in the northbound direction are significantly lower than those between the Railway Link Road and the A5 in the southbound direction. This corroborates the trend observed in Figure B-7 within Appendix B, that the southbound traffic flow along the A5 “through” Omagh is consistently higher than the flow in the northbound direction. This may be caused by the one way streets in the vicinity of Omagh as described earlier in the section. Additionally, northbound traffic between the A32 and the A5 to the north can avoid any delay on the approach to this junction by using an alternate route around Omagh to the west. This alternate route would not be so appealing to traffic in the
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southbound direction due to the presence of several right-turn movements, and generally smaller delays approaching the A5/A32 junction from the A5 than from the A32.
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Figure 2-31: 12 hour Vehicle Flows at junction of the A5 with the A505 to south of Omagh on Tuesday 29th April 2008 The traffic flows in Figure 2-31 are those at the junction between the A5 and the A505 to the south of Omagh. This figure indicates an almost equal volume of traffic between the two A5 arms of the junction as between the A505 and the arm of the A5 to the north. The volume of traffic between the A505 and the A5 arm to the south is much lower.
2.3.9.2 Major Traffic Movements During May 2008 Roadside Interview surveys were carried along the A5 at a series of locations. The results of this survey are used in the following analyses to indicate the typical trips that pass along Section 2 of the A5. The sector system used and analyses carried out on this survey data are described in paragraph 2.2.9.2 of this report and in Figure 2-16.
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The location of the survey used to represent traffic movements through Section 2 is shown on Figure 2-32. This location is on the A5 immediately to the north of Derry Road roundabout, to the north of Omagh.
Figure 2-32: Location of survey used for Traffic Movements through Section 2 Within Appendix B, Table B-12 to Table B-17 inclusive report these traffic movements for a May 2008 weekday.
In all 3 time periods, Section 2 of the A5 carries a high flow of traffic to and from County Donegal (sector 9).
The dominant direction of travel in the morning peak is southbound. More than three-quarters of southbound trips in the morning peak are bound for locations in sector 3 (Omagh area). Half of these trips begin in the Strabane area, sector 2. Nearly one third of northbound trips in the morning peak are bound for sector 9 (Co Donegal), and another third bound for sector 2.
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Table B-14 and Table B-15 in Appendix B show that during the interpeak, almost half the northbound trips originated from within sector 3. A similar proportion of southbound trips were bound for locations in sector 3.
Approximately 10% of trips along this section in either direction during the interpeak were those traversing Northern Ireland between locations in Republic of Ireland, e.g. between County Donegal and County Monaghan.
Table B-16 and Table B-17 in Appendix B indicate that movements along Section 2 in the afternoon peak period resemble the reverse of those during the morning peak. The peak flow direction in the afternoon peak is northbound. Most of the northbound trips are from locations in sector 3, with about half of these bound for locations in sector 2. There is a greater distribution of trips across sectors in the afternoon peak than during the morning peak, especially those sectors in the Republic of Ireland, i.e. some sector to sector movements not observed in the morning peak were recorded during the afternoon peak.
Southbound vehicle movements in the afternoon peak are principally bound for locations in sector 3, many of these trips originating in sectors 1, 2 and 9 (in the vicinity of Londonderry, Strabane and County Donegal, respectively).
2.3.9.3 Journey Time Analyses A journey time analysis was undertaken as described in paragraph 2.2.9.3 of this report and in Figure 2-18.
Section 2 combines journey time routes 5/6, 7/8, 9/10 and 11/12 and is approximately 31 km long, running from south of Strabane to south of Omagh.
The southbound route along the overall length of Section 2 has been given the route identifier 201 and its corresponding northbound route has been given the identifier 202.
The results for Section 2 are shown in Table B-18 within Appendix B.
Table B-18 shows that Section 2 journey speeds are similar between time periods. The section of Omagh around the Throughpass (routes 11/12) has speeds in the order of 25 to 30km/h lower that the “rural” lengths of road through this section (e.g. routes 9/10).
2.3.9.4 Section Two Accident Data Analysis Combined Link and Junction Analysis – Appendix B, Table B-19 There are 3 main line links of the A5 in Section 2. Each had lower observed accident rates (combined link and junction) than the COBA average. Within the Omagh urban area, the accident rate was approximately one third that of the expected COBA rate. However, although the number of personal injury accidents (PIA’s) was lower than expected, the observed severity split in Section 2 was more severe than COBA default proportions throughout.
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Between 2003 and 2006, there were 2 fatal accidents on the A5 and its junctions in Section 2. One of these was between Sion Mills and Newtownstewart and the other was between Newtownstewart and Omagh. There were also 24 serious accidents, five of which occurred within the Omagh urban area.
It should be noted that the values presented are those along the A5 prior to the opening of A5 Throughpass Phase 3. Sufficient accident data was not available for the period since this recent scheme opened.
Two key side roads in Section 2 had accident rates that were slightly higher than COBA averages for the equivalent road types. These were the B165 between the A5 at Victoria Bridge and Clady, and the B50 from the A5 to the limits of the study area.
The observed accident rate on the B50 link was similar to the COBA average rate, at 0.43 (PIA/MVKms) compared with 0.40. The observed severity split was slightly higher than the COBA proportions. The observed F+S/PIA ratio on the B50 in Section 2 was 0.286, due to 2 fatal and 2 serious accidents on this link and it’s junctions, which compares with a COBA average severity split of 0.222.
The B165 is located south of Strabane and connects Clady near the Republic of Ireland border with the A5 between Sion Mills and Victoria Bridge. There were 3 PIAs on this section of the road between 2003 and 2006. These gave an observed accident rate of 0.50, compared with the COBA average of 0.40. All 3 accidents had a slight severity so the F+S/PIA ratio on the link was zero, whereas COBA expects 22% of the PIAs to be either serious or fatal along this type of road.
Link-Only Analysis – Appendix B, Table B-20 The observed accident rates for the A5 main line (link-only) in Section 2 showed a similar pattern to the combined link and junction analysis. The observed accident rates on the 3 links were consistently lower than the COBA default rates, with the observed rate on the A5 within Omagh urban area only one third of the COBA default value.
Both of the fatal and more than half of the severe accidents on the A5 in this section are attributable to links rather than junctions. The A5 within Omagh (urban) is the only link in this section to have 0 serious and fatal accidents within the links (only). The 2 lengths of A5 between Sion Mills and Newtownstewart, and Newtownstewart to Omagh both had higher F+S/PIA ratios than the COBA default proportion.
Along the Omagh urban section of the A5 there are no fatal or serious accidents within the link-only analyses. This indicates that the five serious accidents featured along this section in the ‘combined link and junction’ analyses were attributable to junctions.
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the limit of the study area. The remaining routes that were assessed had lower F+S/PIA ratios.
All 4 of the fatal and serious accidents along the B50 between Omagh and the limit of the study occurred along ‘links’ (i.e. none in proximity to junctions). The observed F+S/PIA ratio for this link is therefore higher than the COBA default. The 11 personal injury accidents along this link result in an observed accident rate only slightly higher than the COBA default.
The seven fatal and serious “link” accidents occurring along the B48 between Omagh and Gortin result in an observed severity split higher than the COBA default. However, taking into account all PIA accidents the overall observed “link” accident rate is significantly lower that the COBA default.
Junction Analysis – Appendix B, Table B-21 Seven strategic junctions have been analysed in Section 2 which are labelled numbers 7-13 in the Table. There is presently an additional junction in this section with significant traffic flows that is not included in the accident analysis. This is the A5/A505 Crevenagh Road junction in Omagh, which became operational in August 2006. Less than 1 year of accident records are currently available for analysis and therefore, the junction cannot be analysed with other strategic junctions in the study area. However, it is noted that Northern Ireland police accident records show that the junction had zero accidents during the first six months after it opened, up until March 2007.
Of the 7 analysed junctions in Section 2, only one had more than half the number of accidents forecast using COBA default calculations. This was junction 7 near Sion Mills, where the A5 Melmount Road/Mulvin Road intersects the B165 Bells Park Road. This had two observed accidents between 2003 and 2006. This is the same number that COBA would calculate at the junction (over the 4 year time period). Junctions 8 and 10 both had zero PIAs over the four year study period, and junctions 9 and 13 only had one each.
There were no fatal accidents at the strategic junctions in Section 2. Junctions 11 and 12 were the only junctions to have serious accidents. Junction 11 had one serious accident of the 2 Personal Injury accidents (PIAs) that occurred between 2003 and 2006. Junction 12 had 2 serious accidents out of the eight PIAs observed there. Due to the low value of total observed PIAs at both junctions, the F+S/PIA ratios were both above that expected by COBA.
Summary The PIA rates on the A5 in Section 2 were less than the defaults expressed in COBA. However, this did not apply to the side roads assessed where the PIA rate exceeded the COBA default.
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The severity of accidents on the A5 was generally greater than expected. This also applied to four of eight key side roads in this section. However, there were 5 key junctions on the A5 where no serious or fatal injuries occurred.
2.4 Existing Conditions – Section 3 South of Omagh to Aughnacloy 2.4.1 Description of Current Network The existing A5 for Section 3 is approximately 32km in length and runs from Doogary to the border south of Aughnacloy joining the proposed N2 in the Republic of Ireland. The existing A5 passes through Doogary, Tullyheeran, Gortaclare, Garvaghy, Seskilgreen, Ballygawley and Aughnacloy. Outside Ballygawley the existing A5 (Omagh Road) joins the Annaghilla Road (A4) at the Ballygawley roundabout before continuing south to Aughnacloy along the Tullyvar Road (A5). It continues to Aughnacloy prior to joining the existing N2 in the Republic of Ireland.
There are natural and man-made constraints along the existing A5 which obstruct upgrading possibilities. The man-made constraints include
• Primary school, St Matthew’s church and filling station in Garvaghy hamlet (Ch. 70550 – Ch. 70700),
• Glencull Parochial House & Primary School (Ch.74900 - 75200).
There are also a number of settlements comprising commercial properties such as shops, filling stations, pubs and housing throughout the stretch of the existing A5 from Omagh to the Republic of Ireland border south of Aughnacloy.
The settlements in Section 3 fall within either Omagh Area Plan 1987 - 2002 or the Dungannon & South Tyrone Area Plan 2010. Like any developments, housing, industry, commerce, community facilities and recreation/open space are situated at convenient locations in the community. Various cultural, landscape and environmental features also dot the surroundings of the A5, such as a broad rounded ridge that forms part of the Brougher Mountains, Clogher Park, The Thistle, and Favour Royal. Major planning permissions in this region include proposed GAA Development Complex (approval in 2007 – construction started) at Garvaghy and a Wind Farm Development (approved 2007 – construction completed) at Slievemore Hill.
The main economic activities in the region are agriculture. There are expansive areas of private and Department of Agriculture and Rural Development (DARD) Woodlands, and agri-environmental schemes. Major watercourses within Section 3 known to be used extensively by anglers consist of the Blackwater (passing to the south of Aughnacloy) and the Owenreagh, Quiggery, Cloghfin and Camowen Rivers. One Public Angling Estate (White Lough) is located approximately 3km east of Aughnacloy and is designated as a rainbow trout fishery.
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Public transport is run by Translink. Bus services in this area are fairly limited, with the only rail connection to the west being the Belfast-Coleraine-Londonderry line. This is due to the predominance of agriculture in this region; most people use their own vehicles for transportation. The bus routes in this corridor consist of the Ulsterbus services and serve the main settlements of Omagh, Ballygawley and Aughnacloy.
Sustrans are responsible for the National Cycle Network. The cycle route for this region is designated as Route 92 Enniskillen to Derry, and travels through Omagh and Fintona.
Figure 2-33: Overview of Section 3: Preferred Corridor, Development Limits and Intersecting Routes/Links within section 3
2.4.2 Existing Highway Conditions The majority of the existing A5 from South of Omagh-Doogary to the border with the Republic of Ireland is derestricted, and is therefore subject to the national speed limit of 60mph. In accordance with the Design Manual for Roads and Bridges (DMRB) TD9/93, this equates to a design speed of 100kph. Some sections have imposed speed limits including 50mph at Garvaghy, 40mph and a 30mph limit through the town of Aughnacloy.
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The geometric assessment of the existing A5 was carried out using the existing speed limits and is graphically presented in drawings 796038-0800-D-00039 to 796038-0800-D-00058, in Volume 4 and summarised (lengths greater than 100m) in Appendix A. The drawings note the variances in speed limit. As shown on these drawings, there are 45 areas that are sub-standard to such an extent that they would require departures from the current standard TD9/93 (DMRB 6.1.1).
Section 3 of the A5 is approximately 32km in length and runs from Doogary towards Tullyheeran (Augher Point Road) where there are 24 private accesses and 13 public accesses. Most sections of road along the A5 in Section 3 are considered to be a high density access constraint, which has an impact on both traffic speed and safety.
Approximately 63% of the road can be classified as below standard with regards to horizontal and vertical geometry and would require departures from standard based on current design standards. In addition to this, 20% and 26% of the sight stopping distances northbound and southbound respectively do not achieve current design standards. The A5 is generally undulating ranging from 69.00m AOD to 167m AOD.
Figure 2-34: Junction with Greenmount Road at Ch 67,400m In the first 1.3km of section 3 of the A5, the road rises from a level of approximately 73.00m AOD to a level of approximately 92.00m AOD. At the junction of the Tullyrush Road and the Doogary Road the level of the road is approximately 102.00m AOD.
The road then passes between Tullyheeran and Gortaclare where there are 9 public accesses and 10 private accesses. The existing A5 alignment for this section rises from approximately 110.00m AOD to a high of 124.00m AOD back down to 110.00m AOD at Gortaclare.
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Figure 2-35: Two+One Southbound from Seskilgreen From here the A5 runs south from Gortaclare to Garvaghy with 18 public accesses and 38 private accesses along this 6.75km stretch of road. The road is undulating in this section rising steeply initially from approximately 122.00m AOD to 140.00m AOD then reducing back to 127.00m AOD before rising steeply again to 141.00m and 167.00m AOD near Garvaghy.
Figure 2-36: Climbing Lane Northbound of Ballygawley Roundabout The road continues south between Garvaghy and Seskilgreen with 7 public accesses and 29 private accesses along this 4.55km stretch of the A5. Once again this section of the road rises and falls sharply ranging between 167.00m AOD and 105.00m AOD at the Ballynasaggart Road outside of Seskilgreen.
The road continues south between Seskilgreen and Ballygawley Roundabout (Grange) with 14 public accesses and 8 private accesses along this 3.0km stretch of the A5.
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Figure 2-37: Pedestrian crossing in Aughnacloy – Moore Street The A5 between Ballygawley Roundabout (Grange) and Aughnacloy, has 14 public accesses and 32 private accesses along this stretch. The A5 has a level of approximately 69.00m AOD gradually rising to approximately 95.00m AOD as it moves south.
Part of the A4 and A5 Corridor Improvements scheme, which is currently being constructed, includes the realignment of 2.7km of the A5 between Ballygawley and Aughnacloy known as the Tullyvar scheme. The scheme follows the existing A5 and then goes off-line as it approaches Tullywinny Road to avoid sharp bends in the existing road. The scheme then ties back onto the existing A5 south of the existing crossroads with Lisginny Road and Aghaloo Road. Climbing lanes are being provided in both directions on Tullyvar hill which has a rising gradient up to 120.00m AOD.
The A5 continues in a southeasterly direction to Aughnacloy before joining the existing N2 at Moy Bridge.
2.4.3 Utilities Electricity, potable water, foul water and various telecommunications are the main services located within the Preferred Corridor. These services are concentrated in, and around, settlement areas, however, transmission lines and trunk mains also traverse the rural areas of the scheme corridor. The existing A5 provides the main utility corridor in the vicinity of the proposed scheme. Details of the major ultilities plant can be found in drawings 796036-0100-D-30001 and 30002 in Volume 4.
2.4.3.1 Electricity NIE have 33kV transmission lines at various locations within Section 3. At the north end of the section a 33kV cable traverses the preferred scheme corridor, running from the south of Omagh towards New Bridge. Another 33kV conductor, again originating from the substation due south of Omagh, continues southerly along the eastern fringes of the Preferred Corridor, occasionally diverting over the boundary into the corridor at Tallyneel and further south due north of the site of the new windfarm at Slieve Divena. Staying within the Preferred Corridor, the cable continues on to Ballygawley.
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NIE have a network of distribution cables within this section, these are more concentrated in and around settlement areas.
2.4.3.2 Water Mains and Sewers NI water have a 450mm – 600mm diameter water main, positioned parallel to and north of the A4 approximately 3km west of Ballygawley Roundabout towards Augher. A 300mm – 450mm diameter water main runs south along the A5 as far as the B83.
The sewerage network within Section 3 consists generally of sewers smaller than 300mm diameter and are mainly within Ballygawley and Aughnacloy.
2.4.3.3 Telecommunications BT has a network of underground and overhead services located within the preferred corridor, predominantly within existing A5 over the full extent of section 3. A significant length of underground cable extends westerly from the Ballygawley roundabout along the Annaghilla Road.
Virgin Media, Eircom and Bytel have apparatus within this section, contained within a common trench and following the existing A5 from Omagh to Ballygawley. Cable and Wireless have services located to the south of Aughnacloy, which generally follows the A5 and A28 roads.
T-Mobile, Vodafone, Orange and O2 have mobile phone base stations/masts located within the Preferred Corridor, throughout this section. Locations as outlined on the appended utilities drawings.
2.4.3.4 Miscellaneous A windfarm consisting of 12 turbines, with a further 8 proposed, is located at Slieve Divena to the east of Garvaghy.
Current utility information indicates that there are no gas pipes located within Section 3.
2.4.4 Geotechnical Engineering The ground conditions in Section 3 of the scheme break easily into 3 zones which are defined by the underlying geology and in particular two prominent southwest- northeast trending geological faults.
Omagh – Gortaclare/Seskinore (Poorly developed Drumlin Topography)
Seskinore/Gortaclare – Ballygawley (the Slievemore Ridge)
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The northern and southern blocks are relatively low lying (drumlin landscapes) with the Slievemore Ridge forming a block of high ground between them. Drawings of the ground conditions for Section 3 are split into the following three categories and can be found in Volume 4.
• Digital Terrain Model/ Drift Geology on drawings 796036-0600-D-30001 & 30002
• Slope Gradient/ Potential Contaminated Land/ Quarry Exents on drawings 796036-0600-D-30003 & 30004, and;
• Solid Geology on drawings 796036-0600-D-30005 & 30006.
2.4.4.1 Topography As the shaded relief plan indicates the northern section (north of Seskinore/Gortaclare) is relatively low lying, with a number of poorly developed drumlins scattered across the landscape. Drumlins vary between 4 & 10m high, are irregular in extent and typically have 1:10 to 1:5 side slopes. There are a number of areas of flat ground occupied by peat bogs north of Moylagh and the narrow, shallow valley of the Camowen cuts into the eastern edge of the Preferred Corridor.
Continuing southeast, between Gortaclare and Ballygawley this section consists of an east/north-east – west/south-west trending ridge of relatively high ground, dominated by the summit of Slievemore (313mAOD) and Slievedivena (290mAOD). The north-west facing slopes of this ridge fall at a shallow gradient towards Omagh and are cut by broad, shallow valleys of the Eskragh Water and Garvaghy Water.
Conversely, the steep south-east facing slope, which is fault controlled, is typically a 1:5 gradient, though locally as steep as 1:3. The ridge is crossed by a number of valleys which have been adopted by the current A5 alignment north-west of Ballygawley and by other minor roads. These valleys are narrow, sinuous, and steep sided.
Land is also constrained by development around the settlement areas of Garvaghy, Gortaclare/Moylagh and Eskragh/Newtownsaville.
In the Clogher Valley the terrain in this area comprises very closely packed drumlins. The drumlins here are better developed and higher than around Omagh, with heights up to 20m and side slopes of 1:8 – 1:5. Deep inter-drumlin areas are often infilled with soft soils. The valley is crossed by the Ballygawley Water and Blackwater River, both of which have locally broad, flat flood plains, 50-300m wide.
To the east of Aughnacloy & Ballygawley, the ground rises to form the rocky high ground of Big Hill, Burnt Hill & Branny Hill (120mAOD) which have localised steep slopes.
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2.4.4.2 Solid Geology Section 3 of the scheme is underlain by Devonian and Carboniferous age rocks that are dominated by sandstone, but with some mudstone and (in the south) limestone. As described above, the strata are divided into 3 distinct fault blocks defined by 2 major east-north-east – west-south-west trending faults:
• The Killadeas – Seskinore and Tempo – Sixmilecross Faults in the north.
• The Clogher Valley Fault complex in the south.
South of Omagh the strata in the Fintona block are formed of the Shanmullagh Formation, of Devonian age. The Shanmullagh Formation is a brown, coarse, pebbly sandstone, with interbedded bands of purple sandstone and mudstone. Outside the peat bogs and between drumlins this sandstone is indicated to be quite close to the ground surface.
The major faults are clearly visible in the terrain mapping between Gortaclare and Ballygawley, and the up-thrust central block forms the Slievemore Ridge, which comprises coarse conglomerates (and minor volcanic lavas) of the Gortinfinbar Conglomerate Formation, again of similar Devonian Age. The conglomerate contains mainly volcanic cobbles, with some quartzite and sandstone. In the north- west of this section, the strata become finer in grain size of the red brown coloured Raveagh Sandstone Formation. Throughout this area, the conglomerate and sandstone will be very close to surface.
The Clogher Valley Fault consists of a complex of several interlinked faults and some of these have dropped down blocks of the younger Ballyness (sandstone) and Clogher Valley (mudstone) Formations. The Clogher Valley Fault complex defines the steep south eastern face of the Slievemore Ridge.
The Clogher Valley is underlain by Carboniferous age rocks of the Clogher Valley and Maydown Limestone Formations. The Clogher Valley Formation is a fossiliferous mudstone, with bands of sandstone and limestone, while the Maydown Formation is a fossil rich limestone. This forms the high ground east of Aughnacloy and is one of the few strata in the district that may be a significant groundwater resource
2.4.4.3 Drift Geology South of Omagh is a number of poorly developed drumlins and locally thick layers of glacial till. Both these tend to be firm red brown very stony clay. Between the drumlins, the hollows have become infilled with soft weathered clay, silt and sometimes peat.
Extensive peat bogs are present in the north of this section around the Tattyreagh – Seskinore Forest area.
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In the south of this section, drift soils are often absent and the underlying rock is close to surface. Soft and/or variable Alluvium can be expected to occur associated with the Camowen River on the eastern edge of the corridor.
The high ground of Slievemore Ridge is extensively drift free with the underlying bedrock close to surface.
Extensive blanket peat bog covers the very high ground but there are also pockets of peat in local hollows, such as can be found to the south east of Garvaghy. The valleys of the Eskragh Water and (to a lesser degree the Garvaghy Water) contain associated bands of variable clay & sand alluvium.
The glacial Ballygawley delta complex which extended north-west from the ridge has left some widespread deposits of sand and gravel, the closest being at Eskragh, on the western edge of the Preferred Corridor.
Drift deposits are thickest in the Clogher Valley where extensive glacial till surmounted with Drumlins is present. Like those near Omagh, the drumlins consist of stony firm clay, but the hollows between drumlins are infilled with soft clay, alluvial soils and frequently peat. These can be of substantial thickness.
The Ballygawley Water and particularly the Blackwater River have wide, but very variable flood plains of soft and variable clay/sand alluvial soils which are expected to have poor bearing capacity.
The high ground to the east of Aughnacloy is largely devoid of any drift cover, with bedrock at or close to surface.
2.4.4.4 Man-made Features, Contaminated Land and Mineral and Mining Resources Man-made Features, Contaminated Land There are a number of disused mills and kilns are located within Section 3 but should present a low risk of ground contamination which may have occurred as a result of accidental spillage of chemicals in storage areas or during processing. A steam fabricators yard is adjacent to the A5 north of Ballygawley in addition to several petrol stations/fuel storage areas located throughout the area including the petrol station at Garvaghy and 5No petrol station/fuel storage areas concentrated around Aughnacloy which may present associated hydrocarbon contamination.
The only significant high risk contamination sites within Section 3 is the active landfill site at Tullyvar and a reclaimed landfill site to the east of Aughnacloy. Potential contamination will depend on the history of the site and the range of materials handled there. Potential hazards include landfill gas which may vent to the atmosphere or migrate into ground around the landfill and leachate breakout to surrounding ground or into the groundwater.
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The disused Clogher Valley railway roughly extends west of the existing A5 alignment and may potentially have ash & cinder contaminates associated there with. A civic amenity recycling centre exists to the west of the A5 at Tullyvar but this contains non hazardous domestic and industrial waste. Two waste water treatment stations exist within the development limits of Gortaclare/Moylagh. Three Sewage Pumping Stations exist southeast of Ballygawley with 2 Waste Water Treatment Works adjacent to the Ballygawley Water at Lisdoart which may present a medium to low risk to ground and water contamination.
Mineral and Mining Resources Active sand and gravel extractions occur in the area at Eskragh and Slievemore however these are outside of the Preferred Corridor. Numerous disused sites of historical mineral extraction are located within the area, all of which are backfilled and the land reclaimed with the exception of 5 areas north and south of Ballymakilroy close to the A5 which may remain as open scars in the landscape and require backfilling.
North of Gortaclare there are approximately 10 small disused quarries and gravel pits which, according to records, are reclaimed. It should be noted that there are a prolific number of disused gravel pits and quarries which are backfilled and 3 disused which may still remain as open scars in the landscape. These are located at, Drumaslaghy, and east and west of the Preferred Corridor close to Lismore Bridge & Glencull.
2.4.5 Hydrology and Drainage Engineering The existing drainage and hydrological features within the Preferred Corridor are described in this section. Specific engineering constraints are outlined in conjunction with information relating to flooding considerations.
Preliminary hydrological assessments have been made in order to ascertain the principal rivers and associated drainage basins within the A5 WTC Preferred Corridor. The main drainage basins are shown in Figure 2-36. The River Blackwater catchment does not form part of the Foyle basin and drains away to the south.
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Figure 2-38: A5 WTC Drainage Basins This section incorporates 4 main hydrological catchment areas. The Camowen basin and the Quiggery Water basin feed into the main River Foyle catchment basin and flow north towards Lough Foyle. The River Backwater catchment in the southern region of the study area supplies the Blackwater and conveys flows towards Lough Neagh.
The Camowen watercourse is approximately 30km in length and flows from its source in the Cappagh Mountain area to the east of Omagh to its point of discharge into the River Strule at Drumragh Bridge in Omagh. Major tributaries of the watercourse include the Cloghfin River, the Owenbrack River, the Altanagh River and the Sluggan River. The catchment area of the watercourse is predominately rural but it does incorporate the small urban catchments of Sixmilecross and Beragh.
The Owenreagh River (Dromore) and Quiggery Water River converge at Relaghdooey approximately 4km south-west of Omagh to form the Drumragh River which then flows for 8km in a northern direction until its confluence with the Camowen River to form the Strule River. The Quiggery Water is formed when the Seskinore and Fintona Rivers converge in Tattyreagh, between Omagh and Fintona. Upstream tributaries of the Seskinore River include the Routing Burn and the Eskragh River which converge approximately 2.5km south east of Seskinore. In general these watercourses flow from a south-east to north-west direction and in doing so feed into the major river systems.
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The principal watercourse in the River Blackwater hydrological catchment basin is the Ballygawley River, which crosses at the south end of the Preferred Corridor. The Ravella and the Aughnacloy River minor watercourses also cross at Aughnacloy.
Through discussions with Roads Service Maintenance Section Offices and Rivers Agency, it is known that sections of the existing A5 within Section 3 have been prone to historical flooding.
• The area to the west of Ballygawley roundabout is liable to flooding.
• Low-lying ground around the River Blackwater near Aughnacloy is liable to flooding.
There are narrow floodplains running parallel to a number of watercourses within this section. These include the Cloghfin River, the Drumragh River, the Quiggery Water, the Owenreagh River (Dromore), the Fintona Water and the Seskinore. In general these floodplains vary in width from approximately 100m to 400m.
The Ballygawley River Floodplain varies from 100m to 500m wide near Ballygawley. The Ravella and Aughnacloy River floodplains approach 1km wide to the west of Aughnacloy. The Lisadavil River Floodplain to the east of Aughnacloy is approximately 200m wide.
The potential for minor floodplain areas have also been identified for the following watercourses: the Roughan River, Annaghilla River, Ballynanny River, and the Tullyvar River.
2.4.6 Existing Structures Conditions This section of the document deals with the assessment of the condition of the existing structures, recommendations on any remedial works required and comments on the options for widening each structure in Section 3. For those sections of the existing route where there are significant constraints to widening the route, such observations are made.
2.4.6.1 Summary of Route There are 9 significant structures in Section 3 having a span greater than 1.8m in length.
All of the bridges carry the A5 over watercourses with no road over road bridges. This is typical of routes in such landscapes where most junctions are at grade. Generally the structures are not very large with a median span of 4.1m but with a maximum span of 9.05m.
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Table 2-14: Bridges by Function and Section
Section Function 3
Footbridge Over Road - Road Over Accommodation - Road Over Pedestrian Subway - Road Over Road - Road Over Watercourse 9 Grand Total 9
As indicated in Table 2-14 above, there are a total of 9 significant bridges (i.e. > 1.8m span) on the route. Additionally, there are 3 retaining walls over 1m high which either support the road or retain landscape and/or structures adjacent to the road. The vast majority of these structures are in fair to very good condition and, when considered in isolation, most could be modified for use in a scenario where the existing A5 was widened to dual carriageway, if required. There are also a number of smaller structures (less than 1.8m span) along the route although these were not thoroughly inspected and no condition ratings were assigned.
2.4.6.2 Structure Types Of the significant bridges, there are a wide variety of construction types, with some of mixed construction where the structure has been widened.
Table 2-15: Significant Structures by Road Section
Structure Type Section 3
Composite Concrete & Steel Concrete Arch/Masonry Arch Concrete Box Culvert 2 Corrugated Steel Pipe 2 Half Joints Masonry Arch 1 Masonry Arch/RC Slab 1 Prestressed Concrete Beams 1 RC Pipe RC Slab 2 RC Slab/RC Pipe Steel Truss/Steel Plate Grand Total 9
In addition, there are a number of small culverts (less than 1.8m) whose construction was often unclear as they were submerged or otherwise hidden.
Three retaining walls (>1m high) were identified along the route where failure may impact on the efficacy of the carriageway. There does not appear to be a register of
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retaining walls for this route and therefore not all of the walls which were recorded in the survey may be in public ownership. However, they are included as they should be monitored as part of an asset management programme and they will need to be addressed as part of any proposed A5 widening scheme. For convenience, these walls have been split into four arbitrary height bands:
• Small – less than 3m;
• Medium – 3 to 5m;
• Large – 5 to 9m;
• Very Large – Over 9m.
Table 2-16: Significant Retaining Wall by Size and Road Section
Height Band
Section Small Medium Large Very Large Grand Total
3 2 1 3
Very few construction details were available for inspection for any of the major structures and none for the minor structures or the retaining walls. An assessment of the basic construction type is included in the national database and this has been used as a basis for this study. For the minor structures and retaining walls, no attempt has been made to classify the construction type.
The following tables indicate the size, type and general condition of the structures. As can be seen, the structures are of mixed size and construction type but are generally in fair to good condition throughout although there are a few structures which are in a poor condition. Some relatively minor defects are present and the key information about each structure is presented below.
Table 2-17: Section 3 Structures – Construction Types and Size
NIRS Structure No of Span Width No Structure Name Structure Type Spans (m) (m)
62139 Unnamed Concrete Box Culvert 1 3.1 13.50 61587 Crawford's Bridge Corrugated Steel Pipe 1 4.05 45.00 62208 Monteith's Culvert Corrugated Steel Pipe 1 2.1 30.00 60733 Barony Bridge RC Slab 1 5.8 15.90 62213 Unnamed Concrete Box Culvert 1 2.5 27.30 60316 Clarkes Cattle Creep RC Slab 1 6.2 17.00 60289 Glenchuil Big Bridge Masonry Arch/RC Slab 1 4.3 22.50
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60742 Unnamed Prestressed Concrete Beams 1 9.05 16.80 61010 Unnamed Masonry Arch 1 1.8 12.05
Table 2-18: Section 3 Structures – Condition Ratings [Scores are based on draft Highways Agency standard performance measurement of highway structures (PMHS)]
NIRS Structure No Structure Name Average Assessment Rating
62139 Unnamed Fair 61587 Crawford's Bridge Fair 62208 Monteith's Culvert Good 60733 Barony Bridge Fair 62213 Unnamed Poor 60316 Clarkes Cattle Creep Poor 60289 Glenchuil Big Bridge Fair 60742 Unnamed Fair 61010 Unnamed Fair
Retaining Walls
Table 2-19: Section 3 Retaining Walls – Size, Function and Condition [Scores are based on draft Highways Agency standard performance measurement of highway structures (PMHS)]
Mouchel Wall Length Wall Height Overall Structure No (m) (m) Function Assessment
DUN7 80 3 Supports the A5 Very Good DUN8 80.2 2.75 Supports the A5 Very Good DUN20 35 2 Supports Farmland Very Good
Widening Issues Approximately one third of the structures in Section 3 would be difficult to widen on line. Typically, the structure itself could be widened but there are existing constraints adjacent to them.
Another one third of the structures could readily be widened on line, if required, although this would be considered further as the design is developed through Stage 3.
The remaining structures would best be replaced, either because they are in poor condition, present vertical alignment difficulties or are considered to be at high risk of needing major repairs in the short to medium term.
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2.4.6.3 Structural Capacity The assessed capacity of the structures is reported in the NIRS database although the records were not complete at the time of inspection.
Of the 9 bridges, all have been assessed as having 40 Tonne HA loading capacity. 5 bridges are rated at 45 units HB, 2 at 37.5 units HB and 1 at 30 units HB. The remaining structure has no HB rating.
2.4.7 Existing Pavement Conditions 2.4.7.1 Deflectograph From this analysis it was found that approximately 32% of the Section 3 has a residual life of less than 5 years, 42% is between 5 and 20 years, and 21% has a residual life greater than or equal to 20years. Approximately 5% of the exisitng A5 in Section 3 has no data available.
No traffic flow statistics were made available during the analysis of the data so no comments can be made on the structural adequacy of the individual sections of the route and its ability to sustain the future traffic loading.
2.4.7.2 Visual Assessment using Digital Video Survey The data represented in this section applies to the entire length of the existing A5. Approximately 48% of northbound and 45% of southbound carriageways are considered to be showing signs of physical deterioration. No rutting is apparent in either direction. The northbound carriageway has the highest concentration of “two- wheel path” cracks while the southbound shows more “one-wheel path” cracks.
The visual survey method used replicates that of a UKPMS visual survey. Therefore, the result of the visual assessment was analysed similar to a UKPMS automatic pass. This process involves all the defects collected being analysed to produce constant defective lengths, which are then given a defect rating. This defect rating is in turn analysed to produce a condition index, i.e. structural or wearing course. The data was then further processed through bespoke scheme analysis software which utilises the condition index values to produce realistic scheme lengths. Therefore the defects recorded from the DV were broken down into condition indices and treatment options.
2.4.8 Baseline Environment 2.4.8.1 Air Quality There are no AQMA’s in Section 3. Data for current concentrations related to the
two traffic-based pollutants (nitrogen dioxide (NO2) and particulate matter (PM10) within this section of the Preferred Corridor indicates that existing levels are well within statutory thresholds defined to protect human-heath (40 µg/m3 for both pollutants)
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In relation to NO2, initial diffusion-tube data collected at key roadside locations indicates a range of concentrations between 5.3 – 14.16 µg/m3 the former being related to B158 Donaghanie Road (Grid Ref 251611, 372794) and the latter to A4 Annaghilla Road (Grid Ref 262288, 356487).
In relation to PM10, there is no monitoring data available for locations within the section. The section is, however, one within which there are no large settlements and where traffic flows associated with the local road network are lower than for the other two sections of the overall corridor. Taking into account the data obtained from the AQMA in Strabane (concentrations range from 20-25 µg/m3) and the lesser scale of potential contributing sources throughout this section, it can be reasonably concluded that concentrations within the section will be lower than those identified at Strabane and they are accordingly well within the statutory threshold levels.
Receptors considered to be sensitive to changes in air quality are located in dispersed hamlets and individual properties throughout this section. Their location is shown in drawings 796036-3000-D-35126 and 35127. Taking into account the full extent of the Preferred Corridor and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 3014 existing receptors who could be subject to increases or decreases in concentrations of the two pollutants. These include 2995 residential properties, 14 schools, 4 medical facilities and 1 residential care home.
Preliminary calculations for regional emissions associated with traffic using the identified network within the section indicate total emissions of nitrous oxides (NOx)
in the order of 171 tonnes/annum. Equivalent figures for PM10 and Carbon (C) are 4 and 13,475 tonnes/annum respectively.
2.4.8.2 Cultural Heritage Archaeology The review of baseline data and information derived from field walkover surveys has established the presence or potential presence of 293 sites or monuments within this section. The location of each is shown in drawings 796036-3000-D-34016 and 796036-3000-D-34017.
There are 121 sites and monuments of which 21 are scheduled and of medium/high value, 44 are Industrial Heritage Sites of medium/low value and 107 potential new sites located during the walkover survey. The latter are of unknown value.
In common with the previous two sections, raths are the commonest archaeological feature found within the landscape of the corridor south of Omagh. There is a marked concentration of raths to the south of the Brougher ridge, there being a rath or enclosure associated with many of the drumlins. North of the ridge the raths are more widely distributed.
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An important group of megalithic tombs are located along the Brougher Ridge in the form of the Sess Kilgreen passage tomb cemetery. There are also a number of more isolated megaliths located on the slopes of the ridgeline. Whilst there is no evidence for the settlements of the people buried in these tombs, their presence suggests a high potential for the discovery of prehistoric settlement.
The Hillfort at Tycanny Hill is a scheduled monument located on the ridgeline. The site dates to the Iron Age and is of national importance.
There are four important ecclesiastical sites located within the section at Aghaloo, Drumragh Bridge, Errigal Kerrogue and Lisdoart.
Figure 2-39: Aerial Photograph of Errigal Kerrogue Favour Royal Bawn is located on the slope of a drumlin in the southern part of the section. This site is an important example of a Bawn (a defensive Anglo-Norman castle).
In relation to archaeological potential, the sites and features identified during the preliminary walkover survey suggest significant potential throughout much of the section. To the south of Omagh, the landform is dominated by increasingly pronounced drumlins, with significant potential for, as yet, undiscovered evidence of dispersed settlement which could date from the prehistoric period through to the post-medieval period. There are routeways over the higher ground of the Brougher Ridge which will have been used since prehistoric times and where there is significant potential for undiscovered evidence beyond the known features identified to date. South of the ridgeline, the land again is dominated by drumlins, with significant potential for prehistoric, Early Christian and medieval remains.
Built Heritage
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There are 15 listed buildings and 8 Industrial Heritage Sites in this section. There are also 62 non-designated built heritage assets which the field survey team has identified during initial walkover surveys. The location of each is shown in drawings 796036-3000-D-34016 and 796036-3000-D-34017.
Although there are assets dispersed throughout the section, the majority are located south of the Brougher ridge. This is an area of fertile land with an abundance of water courses, characteristics conducive to the development of prosperous agriculture and industry.
All fifteen of the listed buildings are listed as Grade B/B1/B2, such that they are of regional importance and have a medium value.
All 8 of the industrial heritage sites are of low value or less.
Most of the 62 non-designated assets are vernacular buildings of low value. Of particular note however, are the remains of Ballygawley Park House (852) and associated Gate House (851) which have a value of low/medium, and the ruins of Garvey House which is of regional importance and has a medium value.
Historic Landscape Characterisation The baseline survey has concluded that there is one area where the combination of landform, land use pattern, field pattern, and complexes of archaeological/built form or design within the landscape warrant consideration in terms of their cultural/historic sensitivity. This relates to the landscape west of Aughnacloy which includes the designed landscapes of the Aughnacloy Thistle and Favour Royal.
2.4.8.3 Landscape The landscape associated with the Preferred Corridor south of Omagh is characterised by extensive areas of drumlin lowland, enclosed and divided by a series of sandstone ridges and local hill forms.
South of Omagh there is an area of intimate drumlin landscape where views are generally localised, though there is an awareness of the extent of the wider landscape where there are occasional broad vistas to the surrounding hills.
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Figure 2-40: Drumlin river landscape south of Omagh Near Gortaclare, the landform of Curr Mountain marks the first real transition in landscape character and a marked change in the zone of visual influence; it is here that the rolling dip slope terrain of the Brougher ridgeline is encountered. Beyond Gortaclare, the Preferred Corridor divides into two around an area of high ground at Garvaghy Big Hill. One corridor follows the existing A5 corridor, the second diverts west of Garvaghy Big Hill to negotiate the Brougher ridge via Kilgreen and Culnaha. The corridors then re-converge at the crossing of the A4 road corridor to the west of Ballygawley.
The landscape along the existing A5 corridor ascends the gentle dip slope of the Brougher Ridge, within the upper valley of the Routing Burn and flanked by the slopes of Garvaghy Big Hill to the west and Slievedivena to the east. Beyond Garvaghy, the corridor reaches the head of the valley and plateaus between the ridge peaks of Knockbrack and Slievemore, marking the highest point of transition across the ridge. Views are contained by these local and distinctive hill forms. The wind turbines on Slievedivena are a prominent feature in close proximity to the corridor.
As the corridor descends from the ridgeline there are interrupted, yet expansive, vistas across the extensive drumlin fields of the River Blackwater towards the distant Slieve Beagh hill mass. An elevated area of hummocky moraine deposits separates Ballymackilroy from the expanse of the more open drumlin field landscapes below. This area has a particular sense of place, heightened by the diversity of landform and the long association of settlement within the valley. There are views from Ballygawley across this part of the corridor.
Within the western corridor, the transition from drumlin landscape to ridgeline dip slope is less pronounced. It is a lower-lying landscape as the corridor skirts Tullanafoile Hill before rising onto the ridgeline west of Tycanny. As it crosses the ridge and begins to descend towards the Clogher Valley the corridor is contained
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within a shallow elevated valley flanked by Beltany Hill, Birney’s Hill and Tycanny Hill. The section of corridor between Glennageeragh and Culnaha is a visually appealing area of coherent landscape character.
The Clogher valley lowlands are broadly confined between the Brougher Mountain and Slievemore ridges to the north and Slieve Beagh to the south. This is a distinctive part of the corridor with a drumlin landform crossed by a network of rivers and streams. Between the drumlins are numerous local water courses, small raised bogs and numerous hedgerows. There is a strong sense of enclosure.
The crossing of the A4 corridor marks a transition as the influence of the Brougher Ridge is left behind. Black Hill, an outlying and conspicuous drumlin/moraine landform marks this point of transition between the higher, rolling terrain of Big Hill/Branny Hill to the east of the Preferred Corridor and the lower valley setting of the River Blackwater to the west.
Views from within and across this landscape are varied. The hill mass of Slieve Beagh is the primary backdrop to elevated views from the corridor. There are filtered expansive vistas towards the rounded, wooded hills of Favour Royal Forest. At lower levels the landscape is markedly more intimate with views contained by the rounded drumlin landforms.
The town of Aughnacloy is located at the southern end of the corridor on the River Blackwater where it leaves the Clogher Valley. Here, the surrounding landscape is one of visually appealing drumlin landform and riverside settings. The historic core of the town is located on a drumlin crest, set above the shallow river margin landscapes and drumlin landforms of the river. Its broad and linear main street accommodates the current A5 and has a strong townscape and visual quality, very much enclosed by its built frontages, yet with expansive views across the landscape where channelled views between, or widespread views behind properties allow. The town’s churches are conspicuous features of the landscape setting, often visible through drumlin landforms and providing a strong sense of place.
West of the town there is a broad and low-lying marginal river landscape with widespread views to distinct and rounded drumlin landforms, with Slieve Beagh a distant backdrop. The influence of the town and of designed landscapes is marked, with extensive views to Ravellea across the “Thistle”, an early 18th Century design laid out in a series of extensive ditches and planted banks. The form of the Thistle is barely evident at ground level but can be noticed from the elevated prospect of the town.
To the east and north of the town, there is a more elevated and enclosed landscape of moraine deposits with restricted views and occasional prospects westwards. As the nature of the terrain rises towards neighbouring hills, the hummocky form and pattern of the drumlins varies, with slightly wider prospects through the river valley connecting Aughnacloy with Carnteel. To the south, the River Blackwater continues
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to influence the drumlin defined valley landscape across the border with the Republic of Ireland.
Landscape Character Areas and Landscape Character Zones Six of the sub-regional landscape character areas identified in the Northern Ireland Landscape Character Assessment are associated with this section of the Preferred Corridor: Omagh Farmland (character reference No.22); Slievemore (character reference No.44); Dungannon Drumlins and Hill (character reference No.45); Blackwater Valley (character reference No.46); Clougher Valley Lowlands (character reference No.17); and Brougher Mountain (character reference No.16). The extent of the character areas is shown in drawings 796036-3000-D-31017 and 796036- 3000-D-31018.
At a more detailed level, the assessment team has identified 18 Local Landscape Character Zones (LCZs). These are shown in drawings 796036-3000-D-31017 and 796036-3000-D-31018. All 18 have been identified as being of good or very attractive quality and high landscape value, such that they would be sensitive to the introduction of the proposed dual carriageway. Ten have been identified as having a low capacity to accept change allowing for the consideration of the potential to mitigate likely impacts. These 10 are:
• Slievelahan Farmlands
• Garvaghy Valley
• Beltany & Tullanafoile Farmlands
• Crocknatummoge Hillform
• Slievemore Ridge Top
• Knockmany Forest & Ridgeline Hilltops
• Ballymackilroy Ridge Moraines
• Killymorgan & Legaroe Hill Slopes
• Branny Hill & Rehaghy Mountain Hillforms
• Aughnacloy
Visual Context and Receptors The following potential visual receptors have been identified:
• scattered properties across the drumlin landscapes to the south of Omagh;
• clustered properties within Moylagh and Gortaclare;
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• properties in and around Newtownsaville;
• properties within Garvaghy and along the adjacent hill slopes;
• residential properties along the Brougher/Slievemore ridgeline, from Ballymackilroy through to Culnaha, Longridge and Glenhoy;
• residential properties to the western margins of Ballygawley;
• scattered properties across the drumlin landscapes crossing the A4 between Ballygawley and Augher;
• scattered properties across the drumlin landscapes between Ballygawley and Aughnacloy; and
• properties bordering the main street in Aughnacloy with direct views to the west and properties to the northern and southern limits of the town with exposed views.
In addition, there are views from a section of the Ulster Way where its crosses the southern part of the section from Favour Royal Forest through to Aughnacloy. There are also several marked trails in the vicinity of Knockmany Forest, a popular local recreational destination. National Cycle Network Route 92 crosses the northern part of the section connecting Fintona with Omagh as shown in drawings 796036-3000- D-32116 and 32117.
2.4.8.4 Nature Conservation Statutory Designated Sites There are no statutory nature conservation sites associated with the section.
Non-Statutory Designated Sites There is one Site of Local Nature Conservation Importance (SLNCI) of county level importance. This is Ravellea SLNCI wet grasslands which constitute a local fen interest and are frequented by waders. This site (Ravellea North and Ravellea South) is also a Royal Society for Protection of Birds (RSPB) breeding wader survey site.
Habitats The principal habitat types identified within the section are indicated in drawings 796036-3000-D-33186 and 796036-3000-D-33187. The more significant examples of the types within the section are outlined below. There are also two records of legally protected plant species within the section, one for birds nest orchid and one for cowslip. Both records relate to locations between Aughnacloy and Ballygawley.
Woodland and Hedgerows
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Significant examples of woodland include areas of mixed woodlands close to Knockmany Forest and north of Aughnacloy.
In common with Sections 1 and 2 the hedgerows within the area, are also an important biodiversity resource in relation to flora and fauna.
Peatland Significant examples of peatlands include Tattykeel Bog and Tullyrush Bog. Both are of national importance. Bogs near Beagh and Near Relaghdooey are of county value and Tullanafoile Hill is of district value.
Watercourses and Waterbodies Significant examples of habitats associated with water courses are located along reaches of the River Blackwater, Drumragh River, Routing Burn, Ballygawley Water, Gortaclare River, Kilgreen River and Roughan River. The Blackwater is of national value and the Drumragh is of County value. The remainder are of District value.
Significant examples of habitats associated with waterbodies include ponds at Fireagh Lough and Lough Muck.
Fauna Invertebrates
The surveys have identified 16 specific areas within the section where it has been concluded that habitats have the potential to support priority species and species of conservation concern (SOCC). The areas of high potential are shown in drawings 796036-3000-D-33192 and 796036-3000-D-33193.
Fish
There are records of Atlantic salmon and brown trout for the Ballynahatty Water, Quiggery Water, Camowen River, Routing Burn, Eskragh Water, Roughan River, and Ballygawley Water. Other freshwater species present within the rivers in this section included lamprey, minnow, stone loach, eel, 3-spined stickleback, and white- clawed crayfish.
Birds
Records relating to breeding birds within the section indicate that the area supports small to moderate populations of generally common species and a small number of less common species though the field surveys noted areas of habitat which are of potential value for a larger number of species than are currently recorded. Higher value areas have been identified to the south of Enderry/north east of Crockacrotty, to the north of Seskinore/south east Crockacrotty, to the north west of Gortaclare, near Moylagh and to the east of Garvaghy/north of Black Hill.
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Otters
A total of 11 locations and stretches of watercourses have been identified during site surveys where the type and status of habitat are indicative of potential breeding sites for otter. These locations are shown in drawings 796036-3000-D-33192 and 796036-3000-D-33193.
Bats
There are a number of locations within the section where bat roosts have been identified and habitat types have been identified as being of biodiversity value in relation to bats (drawings 796036-3000-D-33192 and 796036-3000-D-33193). The most significant include:
• clusters of buildings around Ballygawley, Augher, Seskinore and Gortaclare.
• Seskinore Wood ; and
• woodland habitats such as those near the Greenmount Lodge plantation, Tycanny Hill and Lismore Wood.
2.4.8.5 Materials The solid and drift geology within the section are described in the geotechnical section of this chapter, paragraphs 2.4.4.2 and 2.4.4.3 respectively.
The dominant soil types are Brown Earth and Gleys. They are primarily classified as being of good and moderate agricultural potential (Grades 3a and 3b). The exceptions are areas of peat and high ground where soils are generally of Grade 4 or lower potential, and where there are sands and gravels and soils are generally of Grade 2 potential.
There are no statutorily designated sites of geological value within the section. There are, however, 4 areas which are recognised as having geological value. These comprise the following deglacial complexes; Murrins Complex, Fintona Hills Complex, Ballygawley Complex and Clogher Valley Complex.
There are localised areas of contaminated land in the form of former landfill sites at Tullyvar and near Aughnacloy.
2.4.8.6 Noise In common with Sections 1 and 2, the principal dominant continuous noise source within this section relates to traffic using the local road network with the busiest road being the A5. Preliminary LA10 measurements taken at the immediate roadside indicate existing traffic-related noise levels in excess of 74.5dBA. With increasing distance from the A5 levels will be noticeably lower, as will levels associated with local roads within the section and throughout the rural areas that substantially constitute the Preferred Corridor.
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Receptors considered to be sensitive to changes in traffic-related noise are mostly concentrated within the main settlements of Ballygawley, Garvaghy, and Aughnacloy. Their location in relation to the Preferred Corridor and distribution of more dispersed receptors in the form of hamlets and individual properties is shown in drawings 796036-3000-D-35126 and 35127.
Taking into account the full extent of the Preferred Corridor, and other receptors associated with parts of the wider road network where implementation of the proposed scheme would potentially involve changes in traffic flows, there are some 7779 existing receptors who could be subject to increases or decreases in traffic related noise. These include 159 non-residential receptors including places of worship, rights of way and open spaces, and community facilities.
Site observations indicate that there are no continuous major sources of airborne vibration within the Preferred Corridor.
2.4.8.7 Effects on all Travellers Rights of way in the form of cycleways and long distance footpaths within the section which could be potentially subject to disruption or loss of amenity value depending on proximity to or severance by any of the proposed alternatives are shown in drawings 796036-3000-D-32116 and 796036-3000-D-32117 and are scheduled below.
• National Cycle Route 92 (Foyle Valley Cycle Route) runs from Omagh, to Fintona, crossing the Camowen River and A5;
• Belfast to Ballyshannon cycle route – Cross-country route linking Omagh to Belfast and the Republic of Ireland;
• The Ulster Way long distance footpath – The route crosses the Preferred Corridor at Aughnacloy;
• Seskinore Forest Walk – A short walk with 3 options in Seskinore Forest;
• Carleton Trail – Walk following lanes and forest tracks, connects with Sliabh Beagh Way at Clogher;
• Sliabh Beagh Way – Official Waymarked Way from Auchnacloy to Slibh Beagh then to Lisnaskea.
2.4.8.8 Community and Private Assets Population, Community Facilities and Access The distribution of existing facilities in the form of shops, schools, churches, libraries hospitals, sports and recreational facilities and rights of way providing for access to
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the countryside is shown in drawings 796036-3000-D-32116 and 796036-3000-D- 32117.
There are 3 settlements of note within or in close proximity to the existing A5; Ballygawley, Garvaghy and Aughnacloy. Outside of these, settlement throughout the section is limited to small, frequently dispersed hamlets and individual properties.
Figure 2-41: Aughnacloy Section 3 of the Preferred Corridor is predominantly rural, characterised by small towns, villages, and hamlets, with individual dwellings and farm holdings dispersed throughout the area. As such, many people residing within this section live a relatively long way from their nearest facilities such as GP surgeries, shops, post offices, pharmacists, and larger settlements.
There is a high dependence on Omagh, Ballygawley and Aughnacloy and on other centres including Augher, Clogher, Fintona, Castlecaulfield and Dungannon for educational, medical and recreational facilities and retail outlets other than the local shop.
There is one designated recreation ground located near the existing A5 in Ballygawley. Other recreational facilities include a number of golf courses/ driving ranges. Fishing is also popular particularly on the Drumragh River, Routing Burn, Garvaghy River and River Blackwater.
Private Assets The dominant land use is agriculture, with most of the area being classed as Best and Most Versatile (BMV) land (Grades 3A/2/1). The extent of BMV land in the section is shown in drawings 796036-3000-D-32139 and 796036-3000-D-32140.
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South of Omagh, as far as Tullyrush and Tullyheeran, there is a mosaic of Grade 2, Grade 3a and lower grade land of equal proportion. South of Tullyrush/Tullyheeran to Newtownsaville/Garvaghy the substantial part of the corridor is Grade 3A. Immediately south of Newtownsaville /Garvaghy and along the dip slope of the Brougher Ridge there is a band of Grade 2 and lower grade land across the width of the corridor. Crossing and descending from the ridge to the northern margins of the Blackwater valley Grade 3A land predominates other than for a large area of Grade 2 land south of Ballygawley. At the southern end of the corridor there is a marked band of lower grade land associated with the Blackwater Valley that surrounds Aughnacloy.
There are local concentrations of dairy farms west of Gortaclare/Moylagh and west of Ballygawley along the northern margins of the Blackwater Valley.
The locations of planning approvals granted during the last three years are shown in drawings 796036-3000-D-32145 and 796036-3000-D-32146. Applications of specific note, in relation to the alternatives, comprise two major planning applications to the north and east of Garvaghy; one for the development of a wind farm (now complete), and the other for the provision of a centre of sporting excellence.
Drawings 796036-3000-D-32133 and 796036-3000-D-32134 also show the development limits for Gortaclare/Moylagh, Roscavey, Newtownsaville, Garvaghy, Ballygawley and Aughnacloy.
2.4.8.9 Road Drainage and the Water Environment Surface Waters This section of the Preferred Corridor is located within the catchments of the Drumragh River, Ballynahatty River, Quiggery Water, Routing Burn and Camowen River, which ultimately flow north into the River Foyle, and Ballygawley Water and the Blackwater River which ultimately flow south east into Lough Neagh. Due to the nature of the underlying geology and soils these rivers have a tendency to be slightly ‘flashy’ with high peak flows and rapid response rates during heavy rainfall events and low flows during prolonged dry spells.
All of the watercourses have been classified as moderate to very good for chemical water quality and moderate to good for their biological water quality.
There are a number of areas within the section that are at risk of flooding, although the extents of the individual floodplains are small. These are primarily associated with the larger rivers.
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Figure 2-42: The Ballygawley Water Stream Channel Groundwater Most of the section is underlain by bedrock which forms aquifers of limited or local potential for groundwater. These areas have a low groundwater vulnerability classification, other than where they are overlain by alluvium or sand and gravel and their vulnerability classification is high. Immediately north of Aughnacloy a band of Carboniferous Limestone forms a highly productive aquifer.
Those aquifers found in the section have been classified under the WFD as being of ‘Good’ status for both chemical quality and water quantity.
Peatlands There are numerous, and sometimes extensive, areas of peat in the northern third of the section. Most have been heavily modified and have little ecological value, but are still an important part of the hydrological catchments. Further destruction or modification could alter the hydrological regime of the area. Tattykeel and Tullyrush Bogs are raised bogs fed solely by direct rainfall. The periphery of both has been extensively cut and drained resulting in depressed water levels and associated deterioration in the condition of the bogs.
Water Resources There are no existing public water abstraction points within the section. There are, however, 21 groundwater abstractions primarily related to agricultural and/or private drinking supplies. There are 5 licensed discharge consents. The location of these various abstractions and discharges is shown in drawings 796036-3000-D-37100 and 796036-3000-D-37101.
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2.4.9 Existing Traffic Conditions 2.4.9.1 Traffic Flows
Figure 2-43: Traffic flows in vicinity of Section 3 of the scheme during May 2008 (daily Monday to Thursday average, excluding bank holidays) Figure 2-43 shows typical traffic flows along roads in Section 3 of the A5 WTC scheme. These values are 24 hour weekday vehicle flows (Monday to Thursday). The figure shows that the road with the highest flow in this area is along the A4 to the east of the A5, with a traffic flow of 18,700 vehicles.
The A5 itself carries 24 hour traffic flows of between about 10,800 and 12,500 vehicles to the north of the A4, and between 6,850 and 8,850 vehicles to the south of the A4.
Traffic analyses have been prepared for the location shown by the green triangle in Figure 2-43. This location is on the A5 to the south of the A4 at Ballygawley. The analyses are presented in Appendix B, Figure B-8 to Figure B-10 inclusive.
Analysis of the NIRS long-term (ATC) site 608 is presented in Figure B-8 within Appendix B. This is also the location of the green triangle in Figure 2-50 and is used
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to assess the characteristics of Section 3 of the scheme. The traffic flows through this site are relatively low, the peak flow in each direction being less than 300 vehicles per hour.
Planned improvement works were ongoing along the A4 at the time of the survey. These in particular included operation of heavy plant crossings across the A5 between Ballygawley and Aughnacloy, from May until June 2008.
The operation of these crossings may have had an impact upon traffic flows along Section 3 of the scheme, and so all subsequent analyses have been conducted for the period preceding installation of the crossings.
For the reason stated above the daily traffic profile at the site as shown in Figure B-9 is for April 2008.
Figure B-9 within Appendix B indicates that the flows in the peak hours are not significantly greater than the traffic flows in the interpeak period. The peak hour flows are similar in both directions in both the morning and afternoon, thus demonstrating little tidality.
Figure B-10 within Appendix B shows the distribution of vehicle types through a single day MCC survey on Tuesday 29 April 2008 at the location of the green triangle shown on Figure 2-43. The proportion of vehicle types at this site indicates a lower proportion of cars in the morning and interpeak periods compared with the other scheme sections. There are large proportions of HGVs in the morning peak and also in the interpeak. This suggests that cross-border traffic may have a markedly different composition than traffic between towns within Northern Ireland, comprising of far fewer cars and a much larger proportion of HGVs.
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1 2 10 50 21 4 64 17
0 1 8 30 5 07 D 1 3 23
4 44 2391 4 3061 2 0 7 2 3 0 4 1 2 0 5 3 2
6 8 5 3 3 1 7 2
3 73 3 52 2 NORTH
1 2 2 3 9 6 8 9
Figure 2-44: 12 hour Vehicle Flows at junction of the A5 with the A4 to south of Ballygawley on Tuesday 29 April 2008 Figure 2-44 shows the traffic movements at the two junctions forming the interchange between the A4 and the A5 at Ballygawley. The volumetric surveys carried out on Tuesday 29th April 2008 observed these junctions independently of one another. Consequently the interactions between the two junctions cannot be fully determined from this data.
Automatic Number Plate Recognition (ANPR) surveys were carried out at locations surrounding these junctions on Tuesday 29th and Wednesday 30th April 2008. The ANPR surveys provide further information on movements through this pair of junctions by matching the registrations of vehicles approaching the interchange with those departing from it.
The ANPR surveys indicate that the most significant movements are between the A4 East and A4 West, and between the A5 North and the A4 East. These two pairs of movements have approximately the same volumes. There is also a substantial (but smaller) volume of traffic travelling between the A5 North and the A5 South.
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.
2.4.9.2 Major Traffic Movements During May 2008 Roadside Interview surveys were carried along the A5 at a series of locations. The results of this survey are used in the following analyses to indicate the typical trips that pass along Section 3 of the A5. The sector system used and analyses carried out on this survey data are described in paragraph 2.2.9.2 of this report and in Figure 2-45.
The location of the survey used to represent traffic movements through Section 3 is shown on Figure 2-45. This location is on the A5 immediately to the north of junction with the A28, to the north of Aughnacloy.
Figure 2-45: Location of survey used for Traffic Movements through Section 3 Within Appendix B, Table B-22 to Table B-27 inclusive report these traffic movements for a May 2008 weekday.
These tables show that Section 3 experiences reasonably low traffic volumes. In each time period, a significant proportion of journeys begin or end at locations in the Republic of Ireland, with a reasonable amount of this traversing all the way across Northern Ireland between County Donegal and the other counties of Republic of Ireland.
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During the morning period the peak flow is in the southbound direction, though is not particularly prominent. Most of the southbound journeys in the morning peak begin at locations in the vicinity of Omagh (sector 3) or further to the south, sector 4. In the southbound direction most journeys are bound for locations in the Republic of Ireland (south).
The highest proportion of northbound journeys in the morning period originates from locations in the Republic of Ireland (south), shown in Table B-22. Northbound journeys are destined about equally for either sectors 2, 3 or 9 (in the vicinity of Strabane, Omagh and County Donegal, respectively).
As shown in Table B-24 and Table B-25, during the interpeak period approximately half of the northbound journeys along Section 3 begin at locations in the Republic of Ireland (south). Likewise about half of the southbound journeys are bound for locations in the Republic of Ireland (south). There is a generally wider distribution of trips ends in the interpeak period than during the morning peak, i.e. a number of sector to sector movements not observed in the morning peak were recorded during the interpeak period.
There is no clearly pronounced peak direction in the afternoon period. Table B-26 and Table B-27 within Appendix B show that the locations at which journeys start and end generally follow the same trends as observed during the other 2 time periods.
2.4.9.3 Journey Time Analyses A journey time analysis was undertaken as described in paragraph 2.2.9.3 of this report and in Figure 2-21.
Section 3 is 32 km long and combines routes 13/14, 15/16, 17/18 and 19/20, running from Omagh South to Aughnacloy South. The overall southbound route along the length of Section 3 has been given the route identifier 301 and its corresponding northbound route has been given the identifier 302.
Table B-28 within Appendix B presents the results from the analysis for Section 3.
The average speeds through the Aughnacloy urban area are between about 30 and 40km/h, making it the slowest part of the whole A5 corridor. These low speeds may be due in part to delays at the priority junction of the A5 with the A28 at the south of Aughnacloy. The A5 forms the minor arm of this junction at a location with significant gradients. These factors compound to result in the slow movement of vehicles, especially HGVs.
Also, northbound speeds through Aughnacloy are significantly slower than those southbound through Aughnacloy during the morning and afternoon peak periods. The reverse is true during the interpeak period, when southbound speeds are slower than those northbound.
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2.4.9.4 Section Three Accident Data Analysis Combined Link and Junction Analysis – Appendix B, Table B-29 The observed accident rates on the A5 main line links and their junctions in Section 3 were all lower than the COBA default rates. The rate on the A5 link between the A4 and Aughnacloy was the closest to the default rate with an observed PIA rate of 0.35 compared with the COBA average of 0.38.
On the 2 other A5 links, between Omagh and the A4 and within Aughnacloy urban area, the observed accident rate was less than half the COBA default rate.
There were 4 fatal and 11 serious accidents on the A5 in Section 3 between 2003 and 2006. Three of the fatal accidents occurred on the A5 between Omagh and the A4, the busiest main line link in this section. However, the observed severity splits on all 3 A5 links were less than the COBA default proportions.
Between 2003 and 2006, all the key side roads in Section 3 had fewer personal injury accidents than COBA defaults.
Despite having a higher flow, the eastern link of the A4 had fewer serious and fatal (link and junction) accidents than the western link, from the A5 to Clogher. As a result, the western A4 link had a higher F+S/PIA ratio than COBA ratio, while the F+S/PIA ratio on the eastern A4 link was similar to but less than COBA.
There were no fatal or serious observed accidents on both the B83 (between Seskinore and the A4 near Clogher) and the B46 (between the A5 and Fintona). Two serious link and junction accidents occurred on the B83 between the A5 and Seskinore which caused the F+S/PIA ratio to exceed that of the COBA default proportions.
Link-Only Analysis – Appendix B, Table B-30 In the link-only analysis, the main line A5 links in Section 3 follow a similar pattern to the link and junction (combined) analysis. The A5 between the A4 and Aughnacloy had a similar link-only observed accident rate (0.24) to the COBA default value of 0.23 PIA/MVKm. Both the A5 from Omagh to the A4 and within Aughnacloy urban area had link-only accident rates lower than the COBA default rate.
On the A5 from Omagh to the A4, which has the highest flow of the 3 A5 links in Section 3, 2 of the 3 fatal accidents during the studied period are attributable as ‘link- only’, as well as 4 of the 7 serious accidents. However, the observed link-only F+S/PIA ratio on this link was still lower than expected by COBA. The A4 to Aughnacloy link also had a lower link-only F+S/PIA ratio than COBA. However, the Aughnacloy (urban) section had an observed F+S/PIA ratio exceeding the COBA default.
All observed accident rates on key side roads in Section 3 were lower than the COBA default rates. On the eastern B46 link from the A5 to Sixmilecross, there
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were no personal injury accidents between 2003 and 2006 attributable as ‘link-only’. Similarly, the western B46 link from the A5 to Fintona had a much lower link-only accident rate than the COBA default rate, with only one slight link-only accident during the studied time period.
The B83 from Seskinore to the A4 and both B46 links within the study area each had an observed F+S/PIA ratio of 0. All other key side roads in Section 3 had a similar observed F+S/PIA ratio to the COBA ratio.
Junctions – Appendix B, Table B-31 Section 3 contains five strategic junctions, labelled 14 to 18 inclusive. Junction 16 in Ballygawley, where the A5 Tullyvar Road intersects the A4 Annaghilla Road, had two more observed PIAs (6) than the COBA average (4). All other strategic junctions in Section 3 had fewer than expected personal injury accidents during the study period. Junction 14 (B83 Seskinore Road) had zero observed PIAs even though COBA calculates the junction would have 5 accidents over the 4 years.
There were no fatal injuries at strategic junctions in Section 3 and only 2 serious accidents, both at Junction 16 between the A5 and A4 (west). All other junctions in Section 3 have an F+S/PIA ratio of 0. The F+S/PIA ratio at junction 16 was 0.33, compared with a COBA average value of 0.21.
Summary The PIA rates on the A5 in Section 3 were generally less than the COBA defaults. This also applied to all key side roads in Section 3.
The severity of accidents on the A5 was also generally less than expected in COBA.
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