Preferred Options Report

Transcription

1 Preferred Options Report Preferred Options Report Executive Summary A5 Western Transport Corridor June 2009 Produced for Roads Service Western Division Prepared by Andrew Heap Deputy Project Manager Project Office: Mouchel Shorefield House 30 Kinnegar Drive Holywood County Down Northern Ireland BT18 9JQ T F E andrew.heap@mouchel.com

2 Document Control Sheet Project Title A5 Western Transport Corridor Report Title Preferred Options Report - Executive Summary Revision 1 Status Draft Control Date 23 rd June 2009 Record of Issue Issue Status Author Date Check Date Authorised Date 1 Draft A. Heap P.G. Edwards A. Campbell Distribution Organisation Contact Copies Roads Service Conor Loughrey 2 1

3 Contents 1 Introduction Introduction to the Scheme Background to the Scheme Existing Conditions Sectional Split of A5WTC Sources of Information Existing Conditions Section 1 New Buildings to South of Strabane Existing Conditions Section 2 South of Strabane to South of Omagh Existing Conditions Section 3 South of Omagh to Aughnacloy Development of Preferred Corridor to Preferred Route Development Methodology Preferred Corridor to Preferred Route Focus of Assessment Assessment Process Engineering Process Environment Process Description of Route Options Initial Route Option Assessment Route Options for Assessment Route Development Assumptions 15 2

4 3.6.2 Section Section Section Route Assessment Section 1 Engineering Assessment (Chapter 4 of the Main Report) Section 1 Environmental Assessment (Chapter 5 of the Main Report) Section 2 Engineering Assessment (Chapter 6 of the Main Report) Section 2 Environmental Assessment (Chapter 7 of the Main Report) Section 3 Engineering Assessment (Chapter 8 of the Main Report) Section 3 Environmental Assessment (Chapter 9 of the Main Report) Cost Estimates and Economics Selection of the Preferred Route Section 1 Preferred Route Section 2 Preferred Route Section 3 Preferred Route Cost Estimate and Benefit to Cost Ratio (BCR) Cost Estimate Benefit to Cost Ratio (BCR) Conclusions and Recommendations Conclusions Recommendations

5 1 Introduction 1.1 Introduction to the Scheme Proposals to upgrade the A5 between Londonderry and Aughnacloy have featured prominently in recent strategy documents produced by the Department for Regional Development. In July 2007, the Irish Government indicated its intention to make available a contribution of 400m to help fund major roads programmes in Northern Ireland, providing dual carriageway standards on routes serving the Northwest Gateway and Eastern Seaboard Corridor from Belfast to Larne. The Northern Ireland Executive has confirmed its acceptance, in principle, to taking forward these two major roads projects, which have been included in the Investment Delivery Plan (IDP) for Roads, which was published in April A number of milestones have been agreed, the first of which was the announcement of the Preferred Corridor in late A further milestone is the announcement of the Preferred Route in July The production of this Preferred Options Report is a key part of the process and includes the rationale and process behind the decisions that contribute to the defining of the Preferred Route. 1.2 Background to the Scheme In September 2001, the Department for Regional Development, of which Roads Service is part, formulated Shaping Our Future: The Regional Development Strategy for Northern Ireland 2025 (RDS). An integral feature of the RDS was the requirement to develop a Regional Transportation Strategy having a vision of a modern, integrated and sustainable transportation system which benefits society, the economy and the environment and which actively contributes to social inclusion and everyone s quality of life. In July 2002, the Assembly approved the strategic direction and underlying principles of the Regional Transportation Strategy for Northern Ireland (RTS). Delivery of the RTS is being progressed through three multi modal transport plans, one of which is the Regional Strategic Transport Network - Transport Plan (RSTN - TP), published in March A number of priority schemes to improve the RSTN were ongoing and appraisal work (based on the Government s five key criteria of environment, safety, economy, accessibility and integration) was undertaken to identify further Strategic Roads Improvement (SRI) schemes for inclusion in the RSTN - TP. Delivery of the RDS received a boost in 2005 with the announcement of the Investment Strategy for Northern Ireland (ISNI). The 16bn strategy set out a high level view of planned investment up to 2015 with proposals for up to 1.4 billion of strategic road improvement schemes. In July 2006, Roads Service published the 4

6 consultation document Expanding the Strategic Road Improvement Programme 2015 which included schemes to the value of the ISNI programme as well as a list of schemes that performed well in assessment but were not affordable within anticipated ISNI funding for the period The strategy has recently evolved further in conjunction with the Northern Ireland Executive s Programme for Government and three year budget plan. In 2008 the Northern Ireland Executive agreed it s first three year Budget and endorsed a revised ten year Investment Strategy, covering the period This strategy includes proposals to invest over 3bn, which includes a contribution of 400m from the Irish Government, in the Northern Ireland roads infrastructure. The RSTN TP has 8 primary objectives including the need to examine access to regional gateways and cross border links with an emphasis on improving connections from the 5 key transport and 4 link corridors. The A5 Western Transport Corridor (A5 WTC) is one of the five Key Transport Corridors and starts in the North West of the province at Londonderry and runs for a distance of 88km south to the border, close to the village of Aughnacloy. The A5 WTC joins the N2 in the Republic of Ireland at the Moy Bridge border crossing and together the A5 and N2 provide a strategic link between Dublin and the North West. Within the extent of the scheme itself there are strategic links between the urban centres of Londonderry, Strabane, Omagh, and Aughnacloy. The existing corridor, in addition, provides crucial links from both Dublin and Northern Ireland to urban centres in County Donegal. In October of 2007 Mouchel were appointed by Roads Service to take the scheme through to Preferred Route Announcement. The first major deliverable of this process, the Preliminary Options Report, was published in October 2008 and is available electronically from the A5WTC website, This Preferred Options Report will report on the conclusions of the Preliminary Options Report and will describe the existing engineering, traffic and environmental status of the Preferred Corridor. It will also detail the various route options available to Roads Service for the improvement of the corridor as well as detailing the results and conclusions of the assessment process that has been undertaken in accordance with Roads Service Policy and Procedure Guidelines (RSPPG) E030 Major Road Improvement Schemes - Inception to Construction and TD 37/93 Scheme Assessment Reporting of the Design Manual for Roads and Bridges (DMRB) Volume 5 Section 1. The key purpose of the report is to compare the different route options and, from those comparisons, to make a recommendation for the Preferred Route. 5

7 2 Existing Conditions 2.1 Sectional Split of A5WTC For the purposes of route option development and assessment the A5WTC has been divided into three sections:- Section 1 New Buildings to South of Strabane Section 2 South of Strabane to South of Omagh Section 3 South of Omagh to Aughnacloy 2.2 Sources of Information In order to establish the existing site conditions, data was gathered from numerous sources including, public records, statutory body records and policies, Roads Service records, desk based studies and site surveys. 2.3 Existing Conditions Section 1 New Buildings to South of Strabane The existing A5 within Section 1 is approximately 21km in length and runs 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. South of the river crossing, the A5 continues to traverse between sparsely located residential and commercial properties, while passing through the settlements of Cloghcor and Ballymagorry. The A5 then enters Strabane and continues to 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 along the Strabane Bypass which follows an alignment around the western edge of the town. The A5 then joins Melmount Road at another roundabout at the southern end of Strabane Bypass, before heading south to Sion Mills. There are many natural and man-made constraints along the existing A5 which obstruct upgrading possibilities. These include a number of settlements comprising commercial properties such as shops, filling stations, public houses and housing. The settlements in Section 1 fall within either The Derry Area Plan (2011) or the Strabane Area Plan ( ). There are various cultural, landscape and environmental features both within and surrounding the A5 corridor, such as McKeans Moss and the Rivers Finn and Foyle to the west (and associated floodplain), Strabane Glen, Knockavoe Hill and the West Sperrin Mountains to the east (including the Sperrins Area of Outstanding Natural Beauty). 6

8 North of Strabane, in geotechnical terms, the existing road marks a distinct east west division. To the west of the A5 is the broad flat flood plain of the River Foyle, with extensive sand and gravel but potentially some soft surface soils and localised peat. East of the A5 the ground rises steeply in the foothills of the Sperrins Mountains, formed by ancient metamorphosed sandstones, limestones and mudstones. These mountains are dissected by east-west trending side valleys, some of which are broad with extensive gravel deposits (Burn Dennet Valley) and some of which are very steep sided (Pattens Glen). There are 8 structures (cumulative span greater than 40m) on the existing A5 in Section 1. Existing (24 hour) traffic flows for Section 1 are shown in Figure 2.1 below. 7

9 2.4 Existing Conditions Section 2 South of Strabane to South of Omagh In Section 2, the existing A5 carriageway is approximately 31km in length. It 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 then follows the meander of the Mourne River where it passes through the village of Victoria Bridge and intersects with the B165 (Clady to Douglas Bridge Road) before exiting the corridor again. 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. North of Newtownstewart the B164 (Deerpark Road) joins the A5 at Lower Deerpark. Newtownstewart Bypass, which opened in 2002, follows a route to the north and east of the town where it is intersected by the B46 (Plumbridge Road). The bypass crosses the Strule River twice before tying back into the original A5 to the south-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 Poe Bridge before entering the outskirts of Omagh. The A5 then passes through the urban areas within Omagh and, as such, is outside the Preferred Corridor. There are many natural and man-made constraints along the existing A5 which obstruct upgrading possibilities. These include a number of settlements comprising commercial properties such as shops, filling stations, public houses and housing. The settlements in Section 2 fall within either The Strabane Area Plan ( ) or the Omagh Area Plan ( ). There are various cultural, landscape and environmental features both within and surrounding the A5 corridor, such as the Strule River, the Owenkillew River, Harry Avery s Castle, Grange Wood, Bessy Bell, the Sperrins AONB, Fairy Water and Tully Bog SAC. In geotechnical terms, north of Newtownstewart, the valley system is broad with widespread deposits of sand and gravel (that have been extensively worked), though south of Newtownstewart the valley is narrow and steep sided, with existing roads benched onto the slopes. At the edges of the valley, the ground (formed of the same ancient sandstone/mudstone/limestone strata) rises steeply into the Sperrins and Bessy Bell. There are extensive sands, gravels and alluvial clay associated with the river floodplains which have been proved to be up to 25m deep at Strabane and Newtownstewart. Elsewhere, the bedrock is covered by a variable thickness (generally thinnest or absent on the high ground) of stony glacial clays. 8

10 South of Mountjoy the terrain changes from the steep sided mountains & valleys with ancient bedrocks to a more open, lower-lying character. Around Omagh, the glacial clays are largely much thicker and there are a series of drumlins present (mounds of stony clay) and the hollows between them are likely to be affected by soft clays and peats. There are 14 significant structures (cumulative span greater than 40m) on the existing A5 in Section 2. Existing (24 hour) traffic flows in Section 2 are shown in Figure 2.2 below. 9

11 2.5 Existing Conditions Section 3 South of Omagh to Aughnacloy In Section 3, the existing A5 carriageway is approximately 32km in length. It runs from Doogary (south-west of Omagh) to the border south of Aughnacloy, joining the proposed N2 in the Republic of Ireland. From Doogary it travels south east and passes to the north east of Gortaclare. It continues through Garvaghy to the east of Garvaghy Big Hill until it joins the A4 (Annaghilla Road) at the Ballygawley Roundabout. The existing road then continues in a south-easterly direction to Aughnacloy before joining the existing N2 at Moy Bridge. There are natural and man-made constraints along the existing A5 which obstruct upgrading possibilities, including a number of settlements comprising commercial properties such as shops, filling stations, pubs and housing. The settlements in Section 3 fall within either Omagh Area Plan ( ) or the Dungannon & South Tyrone Area Plan (2010). There are various cultural, landscape and environmental features both within and surrounding the A5 corridor, such as a broad rounded ridge that forms part of the Brougher Mountains, Clogher Park, Errigal Kerrogue, The Thistle and Favour Royal. In geotechnical terms, between Omagh and Ballygawley, the ground rises gently up the north slope of a ridge of Carboniferous age purple sandstone/conglomerate. These rocks are likely to be very close to surface, though there are local pockets of gravel and clay with (especially south of Omagh) peat covering them. The crest of the ridge at Slievemore is also covered by blanket peat. The south facing slopes of the ridge are very steep but are dissected by several narrow valleys, which have been utilised as the existing north-south road corridors. South of the Slievemore Ridge, the Clogher Valley and the area round Aughnacloy is a second well developed drumlin field, with steep sided clay drumlins up to 20m high, though the hollows in between are infilled with soft clays and peat. This area is crossed by the 100m wide floodplains of the Ballygawley Water and the River Blackwater, which are expected to consist of soft clays with some gravel. There are 9 significant structures (cumulative span greater than 40m) on the existing A5 in Section 3. 10

12 Existing (24 hour) traffic flows in Section 3 are shown in Figure 2.3 below. 11

13 3 Development of Preferred Corridor to Preferred Route 3.1 Development Methodology Preferred Corridor to Preferred Route Following announcement of the Preferred Corridor, the development of the Preferred Route was carried out in accordance with the flow chart in Fig 3.1 below. Preferred Corridor identified Review aerial photographs and update constraints information Review constraints to eliminate areas where route options cannot be developed Identify and develop route options Public Consultation February 2009 Undertake initial route option assessments and consider public/stakeholder comments Develop routes within retained sections Determine full length sectional routes, and undertake further assessments Recommend a Preferred Route Ministerial Announcement Preferred Route Exhibitions 12

14 3.2 Focus of Assessment The primary focus of this assessment is to recommend a Preferred Route that can be developed and progressed through the next stage of assessment. The key objectives of the proposed A5 WTC scheme are: To improve road safety, To improve the road network in the west of the Province and North/South links, To reduce journey travel times along the A5 Western Transport Corridor, To provide increased overtaking opportunities for motorists along the A5 Western Transport Corridor, To develop the final proposals in the light of environmental, engineering, economic and traffic considerations. The purpose of this Stage 2 assessment procedure is to critically evaluate the various routes culminating in the selection of a Preferred Route. 3.3 Assessment Process Engineering Process The Engineering assessment has been undertaken in accordance with the guidance detailed in Roads Service Policy and Procedure Guide (RSPPG) _E030 Major Road Improvement Schemes - Inception to Construction and TD 37/93 Scheme Assessment Reporting of the Design Manual for Roads and Bridges (DMRB) Volume 5 Section Environment Process The Environmental assessment has been undertaken in accordance with the guidance detailed in Volume 11 of the Design Manual for Roads and Bridges (DMRB) (as updated August 2008), and reported in this document in accordance with TD 37/93. Volume 11 provides a framework for taking into account environmental interests and assessing and reporting on environmental impacts and their resultant effects. 13

15 3.4 Description of Route Options Four Route Options were developed and displayed at the Public Consultation Events, held in February 2009, namely:- Brown Route Option Pink Route Option Green Route Option Blue Route Option Plans of these route options are contained on drawing numbers D to D in Appendix A of this Executive Summary. 3.5 Initial Route Option Assessment As part of the assessment process, the route options presented at the February 2009 Public Consultation Events were appraised in consideration of comments received from the public and key stakeholders and against the four criteria of engineering, environment, economics and traffic to assist in the development of routes to be taken forward for Stage 2 Assessment. As a result of this appraisal it was considered that: Routes should not be developed south of the Glenmornan River, within the Brown Route Option in Section 1, on the grounds of impact on the River Foyle and Tributaries SAC, River Foyle floodplain and for reasons of poor traffic transfer. With the exception of the area around Newtownstewart, routes should not be developed within the Brown Route Option in Section 2 on the grounds of poor transfer of traffic from the existing A5, poor connectivity to Omagh and south Strabane, and the significant landscape and visual impacts associated with a new road corridor on the eastern slopes of Bessy Bell. Routes should not be developed south of Newtownstewart to north of Mountjoy, within the Green Route in Section 2, on engineering grounds or around Omagh due to poor connectivity. Routes should not be developed within the Brown Route Option in Section 3 on the grounds of poor transfer of traffic from the existing A5 and poor connectivity to Omagh and the A4 dual carriageway. 14

16 Routes should not be developed north of the A4, within the Blue Route Option, as large sections are coincident with other route options. However, discrete sections could be considered to provide links between the Pink and Green Route Options. 3.6 Route Options for Assessment Route Development Assumptions The following approach to road design was taken when developing routes, for comparison purposes, with reference to Chapter 6 of the Design Manual for Roads and Bridges: Design speed 120kph Dual 2 All-Purpose cross-section Departures from Standard only permitted in exceptional circumstances eg. when incorporating the existing A5 into a route option Minimal use of relaxations permitted by standards eg. gradients up to 8% Grade separation of junctions Side roads generally bridged over or passed under Developing the routes to the above criteria presented a worst case scenario when assessing the engineering and environmental impacts and enabled comparable assessment. Further development of the Preferred Route, to be made after its announcement, will reduce impacts along the road. Other specific aims and considerations when developing routes include: Connectivity to future A5/A6 Link; Connectivity to the main towns and communities including Strabane, Sion Mills, Newtownstewart, Omagh, Fintona, Ballygawley and Aughnacloy; Consideration of links to the N14 and N15 in County Donegal; Consideration of links to the N2 in County Monaghan; Consideration of the local road network required as roads are crossed by the route options; 15

17 Minimization of loss of residential and commercial properties and community facilities; and Avoidance, where possible of significant statutory undertakers apparatus Section 1 As a result of the above the following routes were developed in Section 1 for assessment:- Purple Route; Black Route; Pink Route; Green Route It should be noted that new colours for routes were used when combinations of sections of route options were utilised. A plan of these routes is contained on drawing numbers D and D in Appendix A of this Executive Summary Section 2 As a result of the above the following routes were developed in Section 2 for assessment:- Yellow Route; Black Route; Red Route; Purple Route. It should be noted that new colours for routes were used when combinations of sections of route options were utilised. A plan of these routes is contained on drawing numbers D and D in Appendix A of this Executive Summary. 16

18 3.6.4 Section 3 As a result of the above the following routes were developed in Section 3 for assessment:- Green Route Pink Route Purple Route; Red Route. It should be noted that new colours for routes were used when combinations of sections of route options were utilised. A plan of these routes is contained on drawing numbers D and D in Appendix A of this Executive Summary. 17

19 4 Route Assessment 4.1 Section 1 Engineering Assessment (Chapter 4 of the Main Report) In Section 1 the key issues differentiating the routes in terms of Engineering Assessment are:- Buildability difficulties associated with the Purple and Green Routes; Departures from Standard and Relaxations required on the Purple and Green Routes; The Pink and Black Routes provide greater connectivity to Strabane due to the link to the A38 and the proximity of potential junctions to the border. They also cater for a larger number of local movements in addition to enhancing strategic traffic movements; The Black Route has the shortest additional carriageway requirements to serve the new link to the ROI at Strabane. The Purple and Green Routes require significant additional lengths of carriageway to facilitate the crossing; The Pink and Black Routes may have very large impacts on flooding and the flood plains of the River Finn and River Mourne and require significant lengths of multi-span viaduct; The Green Route requires earthworks of a massive scale (deep rock cuttings); The Pink Route utilises a length of the existing A5 via the Strabane throughpass, which would restrict standards (50mph speed limit) and compromise the scheme objectives in terms of providing a high quality dual carriageway throughout; A junction provided on the Pink and Purple Routes to the south-west of Strabane provides greater connectivity to the south west of the town but requires further development land to do so. The Green Route offers the greatest benefits in terms of journey time savings for strategic traffic but attracts the least volume of traffic; 18

20 4.2 Section 1 Environmental Assessment (Chapter 5 of the Main Report) In Section 1 the key issues differentiating the routes in terms of Environmental Assessment include:- The Purple Route, Black and Pink Routes would have similar impacts on the low lying valley floor west of the existing A5, whilst the Green Route and southern part of the Purple Route would have a severe and significant impact on the landscape character associated with the foothills and tributary valleys that constitute the eastern margin of the Preferred Corridor and that frame the Foyle Valley to the east; Landtake from the Bready Cricket Club at Magheramason under the Green Route; Potential impacts of the Black, Pink and Purple Routes on populations of wildfowl that use the part of the Foyle flood plain known as Grangefoyle; Landtake from McKeans Moss ASSI under the Black, Purple and Pink Routes; The loss of the Grade B1 listed Castletown House under the Black Route; The impact of the Black and Pink Routes on Strabane Canal Scheduled Monument; The Green Route and southern part of the Purple Route would have severe and significant impact on landscape character, particularly east of Strabane; Potential impacts of the Black Route on the internationally designated Special Area of Conservation (SAC) associated with the River Finn, south of Strabane; Potential impacts of the Purple and Green Routes on the landscape, ecology, surface and ground water regimes of the nationally designated Strabane Glen ASSI. 4.3 Section 2 Engineering Assessment (Chapter 6 of the Main Report) In Section 2 the key issues differentiating the routes in terms of Engineering Assessment are:- The Red and Purple Routes have potentially large/very large impacts on flooding and flood plains. 19

21 Buildability difficulties of the Purple and Red Routes around Newtownstewart in terms of required closures of the existing road; Departures from Standard and Relaxations required on the Purple, Red and Yellow Routes; Significant structures will be required, on poor ground, to cross the Strule River at Newtownstewart on both the Purple and Red Routes; Poor ground conditions on significant sections of the Purple Route; The Yellow and Black Routes include earthworks of a large scale; Potential large number of watercourse diversions and culverts associated with the Yellow Route. The Black, Red and Purple Routes offer the better connectivity to Omagh via the existing A5 and A Section 2 Environmental Assessment (Chapter 7 of the Main Report) In Section 2 the key issues differentiating the routes in terms of Environmental Assessment include:- The Yellow and Black Routes would have significant impacts on the setting and amenity value of Harry Avery s Castle; The Red and Purple Routes would have significant impacts on the Pubble Friary and graveyard; The Black and Yellow Route Options are prominently located on the high ground west of Newtownstewart and on the slopes of Bessy Bell whilst the Red and Purple Routes would increase the influence of the existing road corridor in the attractive composition of town and valley below; The Red and Purple Routes would involve the loss of high value woodland at Grange Wood ASSI; The Red and Purple Routes have the potential to impact the aquatic and marginal habitats along a 5km reach of the Owenkillew and Strule Rivers (part of the River Foyle and Tributaries SAC); 20

22 The Black, Red and Purple Routes would have significant impact on an area of well-wooded landscape near Mountjoy, these woodland areas also provide important habitats for protected species; The Black, Red and Purple Routes would result in severance at Mountjoy. 4.5 Section 3 Engineering Assessment (Chapter 8 of the Main Report) In Section 3 the key issues differentiating the routes in terms of Engineering Assessment are:- Buildability difficulties of the Purple and Pink Routes in areas close to the existing A5; Departures from Standard and numerous Relaxations, due to topography and alignment, would be required on the Purple and Pink Routes; Remoteness of Green Route affects accessibility for construction purposes; Large cuttings (up to 21m deep) associated with the Green and Red Routes; The Green Route has the most potentially large/very large impacts on flooding and flood plains; The Red and Green Routes provide the better connectivity to Fintona via the B46; Poor connectivity of the Green Route to the existing A4 and A Section 3 Environmental Assessment (Chapter 9 of the Main Report) In Section 3 the key issues differentiating the routes in terms of Environmental Assessment include:- The Green and Red Routes would have large adverse impacts on landscape and visual context between Gortaclare/Moylagh and Ballygawley; The Green, Red and Pink Routes encroach on the settlement limits of the hamlets of Gortaclare and Moylagh; The Green and Red Routes both result in a major adverse impact on Errigal Keerogue ecclesiastical site; The Green and Red Routes have the potential to cause significant impacts to bats (European protected species); 21

23 The total number of potential visual receptors is similar for the Green, Pink and Purple Routes, whilst the Red Route would have an impact on a markedly lower number of receptors; The Green Route causes the greatest level of impact on landscape and visual context around Aughnacloy; The Red Route would result in the loss of part of the Lissenderry Golf Course and part of a graveyard to the north of Aughnacloy; The Green Route results in a significant adverse impact on The Thistle Registered Park, Garden and Demesne. 4.7 Cost Estimates and Economics Cost estimates for each route were calculated sectionally, based on a level of design detail suitable for a Stage 2 Assessment, to provide a range of scheme cost estimates that were used for the economic comparison of the various full length routes. These are detailed in the main report. Economic evaluations, based on the aforementioned costs and the calculated benefits for the various full length routes were also carried out and used in to inform the decision on the Preferred Route. Again, these are detailed in the main report. 22

24 5 Selection of the Preferred Route 5.1 Section 1 Preferred Route Following due consideration of the assessments undertaken and reported in Section 4 of this Executive Summary, it is recommended that the following route is selected as the Preferred Route for Section 1. The Purple Route is preferred from the commencement of the scheme south of New Buildings. It continues south before adopting the Black Route, at approximately Chainage 8000, for the remainder of Section 1. The Preferred Route in Section 1 is summarised below: Single carriageway bypass to the west of New Buildings; The dual carriageway starts south of New Buildings; Passes west of Magheramason; Passes east of Bready; Passes between Drumgauty and Magherareagh; Passes west of Cloghcor and Ballymagorry; Skirts the western edge of Strabane town, before heading south-east towards Glebe and Sion Mills. There are proposed junctions at the following locations: J1.1 - Towards the centre of the single carriageway New Buildings Bypass; J1.2 - South end of the single carriageway New Buildings Bypass; J1.3 - North of Strabane on the existing A5; J1.4 - West of Strabane on the A38 (Lifford Road)/existing A5; J1.5 - West of Strabane on B85 (Urney Road). This junction will also accommodate the new Lifford (N14/N15) Link; J1.6 - North-west of Sion Mills on the existing A5. 23

25 A plan of the Section 1 Preferred Route is contained on drawing numbers D and D in Appendix A of this Executive Summary. 5.2 Section 2 Preferred Route Following due consideration of the assessments undertaken and reported in Chapter 4 above, it is recommended that the Black Route should be taken forward as the Preferred Route for Section 2. The Preferred Route in Section 2 is summarised below: Starts between Sion Mills and Glebe; Passes to the west of Seein; Passes to the west of both Newtownstewart and Harry Avery s Castle; Traverses the lower slopes of Bessy Bell before passing to the west of Mountjoy, roughly following the path of the disused railway line; Follows a line close to the western outskirts of Omagh There are proposed junctions at the following locations: J2.1 - Adjacent to Victoria Bridge on the B72 (Fyfin Road); J2.2 - West of Newtownstewart on the B84 (Baronscourt Road); J2.3 - North-west of Omagh with the existing A5; J2.4 - South-west of Omagh on the A32 (Clanabogan Road); For the location of the junction south of Omagh, see section 5.3 below. A plan of the Section 2 Preferred Route is contained on drawing numbers D and D in Appendix A of this Executive Summary. 5.3 Section 3 Preferred Route Following due consideration of the assessments undertaken and reported in Chapter 4 above, it is recommended that the Preferred Route for Section 3 initially follows the alignment of the Red Route as far as the A4 before adopting the Pink Route for the remainder of Section 3. 24

26 The Preferred Route in Section 3 is summarised below: Starts south-east of Omagh at Doogary; Passes west of Moylagh; Passes east of Newtownsaville; Passes west of Garvaghy Big Hill; Passes west of Ballygawley; Passes west of Tullyvar; Passes north of Aughnacloy before bypassing the town to the east; Ties in to the existing A5 north of the border at Moy Bridge with a single carriageway link between the A28 and the existing A5; There are proposed junctions at the following locations: J3.1 - South of Omagh on the existing A5; J3.2 - South-west of Moylagh on the B46 (Moylagh Road); J3.3 - South-west of Ballygawley on the A4 (Annaghilla Road); J3.4 - South east of Aughnacloy on A28 (Caledon Road) A plan of the Section 3 Preferred Route is contained on drawing numbers D and D in Appendix A of this Executive Summary. 25

27 6 Cost Estimate and Benefit to Cost Ratio (BCR) 6.1 Cost Estimate The purpose of the Stage 2 cost estimates is to differentiate between the alternative route options in terms of affordability and scheme economics, and not to set the scheme budget. The rates used for pricing are consistent to each section and no consideration has been given to potential value engineering savings. The Stage 2 cost estimates are based on Q prices and are based on a combination of unit rates and measured quantities. The majority of the pricing information was obtained from analysis of costs for previous and current roads projects in Ireland including A1/N1 Newry Dundalk Link Road, M8/N8 Cullahill to Cashel and A4/A5 Dungannon to Ballygawley. Current market prices were obtained for the surfacing works. The following are included in the Stage 2 cost estimates:- Stage 2 design information; Construction costs; Land costs; Other costs including contractor s overhead and preparation and supervision costs; Risk based on a Monte Carlo type analysis; Optimism Bias applied in accordance with Director of Engineering Memorandum for Major Works Estimates. As described in Section 4 of this Executive Summary, cost estimates for each route were calculated sectionally, based on a level of design detail suitable for a Stage 2 Assessment, to provide a variety of overall scheme cost estimates. Further, more detailed, work was then carried out on the design and cost estimate of the Preferred Route in order to provide a more robust figure for affordability and use in the economic assessment of the Preferred Route. This is work that is normally carried out as the design is developed through Stage 3. The cost estimate for the Preferred Route, based on this work is 844,303, Benefit to Cost Ratio (BCR) An economic evaluation of the Preferred Route based on the above cost, and the calculated benefits arising from the scheme was carried out and provided a Benefit to Cost Ratio (BCR) of

28 7 Conclusions and Recommendations 7.1 Conclusions A plan of the Preferred Route is contained on drawing numbers D to D in Appendix A of this Executive Summary. The cost estimate for the Preferred Route is 844,303,296, which results in a BCR of Recommendations On the basis of the Stage 2 Assessment described in this report, it is recommended that the Preferred Route, shown on drawing numbers D and D in Appendix A of this Executive Summary, be taken forward and progressed through a Stage 3 Assessment (TD 37/93) culminating in the preparation and publication of the Statutory Procedures, including Notice of Intention to Make Vesting Order (NIMVO), Notice of Intention to Make Direction Order (NIMDO) and the Environmental Statement It is also recommended that, in accordance with the Habitats Regulations Assessment, the Appropriate Assessment procedure is completed for all locations where the Preferred Route crosses the River Foyle and Tributaries SAC. Continued liaison with Irish Government officials has ensured that adequate provision has been made for connectivity with the road network in the Republic of Ireland. It is recommended that the cooperative working with Irish Government officials continues with a view to maximising the benefits of the A5 project through delivery of cross border linkages. 27

29 See Separate Folder for Appendix A - Drawings 28