This Report is presented to Transport Scotland in respect of the A75 Trunk Road Improvements – Hardgrove to Kinmount and may not be used or relied on by any other person or by the client in relation to any other matters not covered specifically by the scope of this Report.
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This Report has been prepared by Mouchel. No individual is personally liable in connection with the preparation of this Report. By receiving this Report and acting on it, the client or any other person accepts that no individual is personally liable whether in contract, tort, for breach of statutory duty or otherwise.
Introduction
Transport Scotland is proposing to improve the overtaking opportunities along a 3.6 km section of the A75 Trunk Road (the A75) between Carrutherstown and Upper Mains Farm; in Dumfries and Galloway. This will be achieved through the construction of a realigned wider single-carriageway to the south of the existing road, which will also include short alternating overtaking sections on either side of the road.
The scheme proposal is called the A75 Hardgrove to Kinmount Improvement and is shown in Figure 1.1.
Background
The case for upgrading the A75 as the key strategic route in South West Scotland and a priority route in the Trans-European Transport Network linking the ferry ports of Stranraer and Cairnryan with the motorway network has been the subject of a route action plan and strategic assessment report for the total 159km trunk road.
These studies were principally based on safety and road layout issues given that the type and volumes of traffic currently using the A75 far exceed that for which the road was initially designed. In turn, this has led to a number of accidents, which have notably increased in the last 15-years.
To improve road safety, decrease journey times and reduce the stressful driving conditions currently experienced along the road at present, it was suggested, as the output of the initial studies, that a number of safe overtaking opportunities should be provided along the A75.
The follow-on studies targeted various key locations along the road that had the worst safety records and were considered the most dangerous. The most notable location was around Hardgrove, where current road-visibility is poor, accident rates are high and there are a number of sub-standard local accesses onto the existing road.
Whilst initial scheme proposals focussed on improving the existing A75 it was soon realised that more benefit would be gained through realigning the A75 to the south and retaining the current route as a local access road to Carrutherstown. This proposal also provided a safer means for the local traffic that currently use the U81a to cross under the A75 via a newly constructed underpass.
The choice to realign to the south was supported by a number of potential environmental issues that would emerge through realigning to the north; chiefly related to the larger number of existing properties to the north and the presence of an important archaeological feature at Braehill.
Environmental Impact Assessment
Given the size and location of the proposed scheme there is a legal requirement to determine the likely predicted environmental impacts that will arise during its construction and once it is fully operational.
The process by which such an assessment is made is well defined in a specialist guidance document relating to the design of roads called the Design Manual for Roads and Bridges (DMRB). The DMRB provides a standardised and accepted approach to the formal process of Environmental Impact Assessment (EIA). A report on the findings of the assessment is also produced. This is called an Environmental Statement (ES); an element of which must include a non-technical summary.
The purpose of the EIA is as follows:
The Scope of the EIA
It is an important principle when undertaking a formal EIA that it only focuses on the potentially ‘significant’ impacts that arise from introducing the proposed scheme in to this part of south east Dumfries and Galloway.
The process by which only significant environmental impacts are addressed within the context of a formal EIA is called ‘scoping’. Scoping continues throughout the EIA process so as to allow various topics and specific considerations to be added to, or omitted, in light of emerging information or preliminary assessment findings.
Volume 11 of the DMRB provides guidance on the environmental interests under which a road scheme of the type proposed may result in specific impacts. These comprise:
During the initial constraints identification exercise and development of scheme options, it was concluded that there was no potential for significant impacts to be associated with three of the above topic areas, and accordingly there was no need to undertake a corresponding full assessment of these during the EIA.
Therefore, operational effects resultant from changes in noise levels and the local air-quality along with the scheme’s impact on the local geology and soils were scoped out; save for the consideration of effects that could occur during the construction phase.
The Existing Environment
The proposed scheme is located within a gently undulating area that is characterised by moderately-sized pastoral and arable fields that are bounded by hedgerows. The local highpoints, which stand-out against the rolling landscape, include a prominent ridge at Braehill (comprising Birch Bank and Oak Wood) and two hillock summits; one immediately south of Popin Moss and the other at Kiln Knowe.
Within the landscape there are a number of dispersed farmsteads, which are surrounded, and therefore screened, by copses of planting, which are there to provide a degree of shelter and privacy. Areas that are less accessible or fertile have been planted with mixed and coniferous plantations, which break-up an otherwise open landscape. The most prominent areas of woodland include Braemoss Wood, Popin Moss, Kelhead Moss Plantation, Popin Well Wood, Braehill Oak Wood and an area of broad-leaved semi-natural plantation located around the Stenriesgate property.
The trunk road and its traffic are a prominent and intrusive feature of the area, whilst side roads and lanes are relatively unobtrusive as they sit more comfortably within the undulating landscape.
Carrutherstown is a small village including a number of white-rendered buildings typical to this area of Scotland. There is a local school with playing field, a village hall and post office. East of the village impressive stone gate posts mark the access to Whitecroft Gate; the pillars are listed features.
The Proposed Scheme
The principal realignment would diverge from the existing A75 at the eastern end of the Carrutherstown bypass, following a line to the south of the existing trunk road before rejoining some 50 m west of the access to Upper Mains Farm.
Opportunities for overtaking would be prioritised for westbound traffic between the Carrutherstown bypass and the U81a; where a second lane for westbound traffic would be constructed. An opposing second eastbound lane would be constructed between the U81a and Upper Mains Farm. The realignment would also include three transition points to facilitate the overtaking sections; at the divergence and convergence points with the existing A75 and around the U81a, where overtaking priority switches from west to east.
Access for local traffic on and off the new alignment would be improved. A retained and modified staggered junction would be created for the B725, whilst a new access on to the realignment would be created immediately east of the access track to Topmuir Farm. The only other direct access onto the new carriageway would be limited to the private access for Topmuir Farm.
In contrast to the existing arrangement, there would be no direct access onto the new section of trunk road from the U81a, U82a or any of the existing farmsteads and private property other than Topmuir Farm. For property to the north of the retained section of the A75, the existing junctions with the declassified trunk road would remain and would provide a means of local access to Carrutherstown segregated from the displaced trunk road traffic. The U81a would be realigned continuing to link into the declassified A75. The new A75 alignment would pass over the U81a via a newly constructed overpass. At Fostermeadow Farm, the lost access onto the A75 would be compensated through the creation of a new access that would be provided by upgrading an existing track running west of the farmstead to the B725.
Environmental Impacts
Cultural Heritage
The assessment has identified a number of known sites of archaeological and built heritage interest in the local area; though none are directly located where any construction works are taking place.
The nearest, most extensive and prominent of the interests locally comprises Braehill Fort and Settlement and Braehill Enclosure located close to the north of the existing trunk road. Movement of the existing traffic onto a new alignment to the south would avoid any direct impact on these interests and would not have a detrimental affect on their setting; which has already been influenced by the feature’s relationship to the existing A75 and its traffic.
The nearest architectural feature of historic interest are the impressive entrance pillars at Whitecroft Gate. These would not be affected or disturbed by the proposals.
There is the potential for discovering previously undisturbed or undetected cultural interests on constructing the proposed scheme; a situation on which Historic Scotland has been consulted. It has been agreed that a pre-construction walkover survey followed by further potential intrusive surveys in the proposed construction corridor would be let and administered by Historic Scotland. This is common practice on similar schemes of this nature.
The assessment has concluded that there would be no residual effects on known sites and features of archaeological or built heritage interest. It has recognised the potential for unknown archaeological sites and features to be uncovered and has accordingly identified an appropriate mitigation strategy.
Ecology and Nature Conservation
There are no designated or important ecological sites in close proximity to the proposed scheme. However, there are a number of habitats of value and protected species that occur locally including badgers, red squirrel, otters and birds.
Of significance, will be the loss of approximately 2 ha of locally-important woodland at Braemoss, Popin Well and Kelhead Moss Plantation and the risk of badger and otter road kill. These impacts, although certain to occur, are assessed as only having an effect on the local ecology. There is also the unlikely potential for a significant ecological impact as a result of the increase in road runoff from the proposed scheme.
Accordingly, the proposed landscaping measures incorporate species that encourage the creation of locally important habitats. The measures include the creation of mixed woodland, scrub and roadside hedgerow and verge.
Five kilometres of wire fencing will be installed 250 m either side of any structure passing under the road; the first 100 m of which will include an overhang. This will exclude badgers and otters from the highway and will be attached to the post and rail fencing used to mark the edge of the highway boundary.
With regards to birds, any construction or operational maintenance works will be ideally timed to avoid peak breeding season, which is considered to be March to August inclusive. Where this is not possible a survey will be undertaken by a qualified ornithologist ahead of any works to check that no active nests would be affected. With regards to barn owl, sections of broad-leaved hedgerows will be planted along the verges of the new alignment where possible. These will be planted with native species where possible and will be maintained at least 2-3m from the edge of the carriageway. Pollutant runoff is being managed through the measures discussed in the Road Drainage and the Water Environment section below.
On including these measures, it is anticipated that the residual effects of the scheme proposals will not be significant, neither in legal terms nor in relation to the local ecological value of the area.
Landscape Effects
Notwithstanding the transfer of most of the traffic from the existing road to the new alignment, the retention of the existing road would extend the overall influence of the transport corridor in the local landscape. With the new alignment there is a need for cuttings and embankments to create the new overpass over the U81a. This would increase the impacts on landform and would be most noticeable for the views gained from the south along the U81a. However, the influence would be locally contained given that the rolling landscape and presence of woodland reduces the extent and value of the views to the south in the area.
Scheme improvements would be made; however to reduce the view of the road and its associated infrastructure dense woodland and scrub would be planted in the existing agricultural land that would be severed and isolated between the two alignments. Once the planting is established it would both screen the road and traffic from many parts of the surrounding landscape and would extend and enhance the influence of woodland and scrub in the area whilst linking established planting areas and enhancing the availability of ecological corridors within the landscape.
Initial moderate/significant and adverse impact on the landscape would reduce to a residual effect of moderate/slight and adverse. In the context of the character of the wider regional landscape, such localised impact along a substantial strategic road corridor would not have a significant impact beyond the immediate landscape between Carrutherstown and Upper Mains Farm.
In the context of an area where the A75 and its existing traffic forms a significant view for some 80 buildings/public places identified by the assessment, it is predicted there would be no significant visual impacts once proposed planting is established and begins to mature. There would be a moderate to slight adverse impact for one property; all others have been assessed as being slight, negligible or no impact.
Land Use
Land locally is primarily used for agricultural purposes. The realignment of the road and its traffic to the south would involve severance of some 4.4 hectares of prime agricultural land. This loss would however be small in the context of the agricultural resource regionally or nationally. In the context of individual land owners, the loss would range between 2-4% of any one holding.
The improvement of the U81a would serve to improve accessibility for holdings to the south; whilst there would be no marked change in access at either end of the scheme.
The scheme would require the demolition of one existing property at Stenriesgate. The property has already been purchased by The Scottish Ministers.
Pedestrian, Cyclists, Equestrian and Community Effects
There are no recognised rights of way within, or close to, this section of the A75. There is also no evidence of significant levels of use of private access tracks or local roads by walkers, pedestrians, cyclists and equestrians. Local access to Carrutherstown for property to the south of the existing trunk road and east of the village is currently dependant on the need to access and cross the existing A75.
The segregation of the new trunk road and U81a crossing and retention of the existing section of trunk road as a local road would improve this situation; this is especially true in relation to the local school, village hall and post office. It would further open up the opportunity for increased use of the local road network by walkers and cyclists as a recreational resource; including the retained section of trunk road.
Vehicle Travellers
The assessment concluded that there would be no significant change in the traveller’s experience related to views from the road. There would, however be a marked reduction in driver frustration and stress, as local and strategic traffic is largely separated, private access onto trunk road would be reduced, and guaranteed overtaking opportunities would be provided.
Road Drainage and the Water Environment
The scheme will see road runoff discharging into two of the local watercourses, the Hardgrove Burn and Glen Burn (which are shown on Figure 4.2 in the main ES). In contrast to the existing situation, discharges would be controlled and the runoff intercepted and treated through the use of three balancing ponds, which will contain reed beds. The new alignment also reduces the risk of accidents; however these pollution control measures provide more protection should an accident occur along the new alignment.
In common with most road construction work there would be the potential for pollution of local watercourses in the form of increased sedimentation as earthworks progress close to watercourses and contamination associated with fuel spillage by construction vehicles or wash off from construction materials such as cement and concrete. Procedures to address these potential impacts are a well defined and integral part of road construction contracts and would be formalised within any contract for the proposed scheme as part of a mandatory construction environmental management plan (cEMP).
The assessment has concluded that with the proposed drainage design and pollution prevention measures during construction, there would be no significant impacts on surface waters.
Policies and Plans
The assessment has included a review of current national, regional and local policies and plans of relevance to the proposals and the local environment. The review has demonstrated that the scheme would either positively support such policies and plans or prove neutral in relation to them.
Disruption during Construction
Construction of the form and extent proposed would inevitably result in some disruption to local communities, landowners and users of the trunk road. It would also potentially involve temporary disruption to some of the natural environmental features and interests associated with the local area above those predicted once the road is complete and open to use.
Those that may be mostly affected by the construction works include the residents at Carrutherstown and the isolated farmsteads and holdings local to the road. Noise and dust inevitably raise concern for such receptors. The assessment has demonstrated that a substantial part of the work would take place at a distance sufficiently far from many of these receptors to be a concern; and where works do occur close-by they will be relatively short-term.
Measures to reduce the level of construction-derived impacts have been identified and would be implemented to ensure that noise levels are controlled in accordance with Dumfries and Galloway Council requirements and that the generated dust will be controlled to prevent its dispersion. Both aspects would be monitored during construction.
Access to the trunk road would be temporarily affected as would the traffic currently using the road. This would be managed in accordance with a traffic management and access plan, negotiated by the contractor with landowners, Dumfries and Galloway Council and trunk road maintenance operator. Minimisation of temporary disturbance to fauna and control of potential discharges to local watercourse would be controlled in accordance with a species protection plan and water management plan.
All mitigation proposed in relation to construction activities and identified in the ES would be implemented via the cEMP.
Conclusions
It is assessed that the scheme proposals will result in a decrease in journey times and the road conditions would become safer and less stressful. This is achieved through constructing a new alignment to the south of the existing A75, retaining and declassifying the current road as a local access and improving access on to the trunk road locally.
The impact of the scheme during its construction is assessed as being greater than during the scheme’s operation; however despite the impacts being temporary, through the introduction of effective management and control measures the associated effects would be appropriately mitigated to a level where the resultant residual effect would not be significant.
The EIA has concluded that post construction and upon the scheme opening there would be no significant residual effects.
Obtaining and Commenting on the Environmental Statement
This ES and copies of the Draft Orders can be viewed during normal working hours at:
Transport ScotlandThe ES can also be viewed on Transport Scotland website: www.transportscotland.org.uk.
Copies of the ES are available in hard copy for £150 or on CD or DVD for £10 (both including postage and packing). VAT is chargeable on DVDs and CDs. The statement also contains a Non-Technical Summary (NTS), which is provided free of charge. The NTS and the main ES are available from the Director of Major Transport Infrastructure Projects at Transport Scotland (address as above).
Comments on the proposals or their environmental effects can be sent in writing to the Director of Major Transport Infrastructure Projects at Transport Scotland at the address given above within six-weeks of publication of the notice of the ES.
