2 The Need for the Scheme
2.0 Strategic Role of the A75 Trunk Road
2.0.1 The A75 has been the subject of ongoing studies relating to its effectiveness as a key strategic corridor since the early 1990s. At that time, Dumfries and Galloway Council investigated the corridor on behalf of the then Scottish Office (latterly the Scottish Executive) with a view to identifying sections that pose a high safety risk. These studies culminated in the identification of a number of Accident Investigation and Prevention schemes (AIPs).
2.0.2 In 1996, a Route Accident Reduction Plan (RARP) specific to the A75 was completed; the objective being to bring the route up to a consistent standard in terms of safety and the ‘level of service’13.
2.0.3 In 1997, the RARP was followed up by a Route Action Plan Study (RAPS), which covered the entire length of the A75. The trunk road was subsequently divided into four sections along its length based on differing standards and traffic conditions. Strategic Assessment Reports (SARs) detailing various strategies were produced for each section; the four studies being combined in a final Firm Strategy Report (FSR).
2.0.4 The SAR relevant to the Proposed Scheme comprised three strategies one of which saw the upgrading of the 7 km section of the A75 between Carrutherstown to the western end of the Annan Bypass. The proposals within this section took the form of the creation of wide-single carriageway with alternating overtaking sections (referenced as WS2+1) and the restriction of side-road access to transitional lengths of road between the overtaking sections.
2.0.5 Out of this it was identified that the section between Hardgrove to Kinmount provided the only positive benefit in terms of safe overtaking; thus the development of the Proposed Scheme.
2.1 Existing Conditions
2.1.1 The existing section of the A75 extends some 3.6 km, from a point immediately south and west of Carrutherstown village to a point some 50 m west of the existing access off the trunk road to Upper Mains Farm (Figure 2.1 – Extent of Scheme). It is a single-carriageway road that does not meet the current design standards required of a strategic route carrying the volumes and mix of traffic that routinely use it.
2.1.2 Recent data indicates that the two-way daily traffic flows on the trunk road are approximately 13,000 vehicles and that 18% of the traffic comprises HGVs (the national average for similar roads is 10%).
2.1.3 Forward visibility is poor. There is no provision for overtaking. There are four side road junctions and six private access junctions within this relatively short section of the trunk road which are used by residents, the local community and farm vehicles on a daily basis.
2.1.4 The result is a section of road where there are significant conflicts between the local/agricultural traffic and the strategic traffic travelling to and from Stranraer and Cairnryan resulting in frequent travel delays and a high accident rate. A total of 56 accidents have been recorded between 1992 and 2007 (2 fatal, 18 serious and 34 slight). The main likely cause of these relates to dangerous attempted overtaking manoeuvres.
2.1.5 Access from side roads onto the trunk road and for turning movements off the trunk road into side roads involves merging with, and crossing oncoming, traffic. This presents a safety issue along with raised levels of driver frustration, stress and anxiety caused by the associated delays.
2.1.6 In light of the strategic and local context for the Proposed Scheme, the following scheme objectives have been identified.
- Improve the operational performance and level of service and safety on the A75 by reducing the effects of driver stress and journey times by constructing guaranteed overtaking sections designed to break up the effects of convoys/platoons.
- Improve and increase the number of overtaking opportunities to eradicate the conflicts between long distance users and the local and agricultural traffic.
- Undertake the construction of one long-term overtaking section which includes carriageway widening, the rationalisation of side road junctions and realignment improvements to junctions, bends and private accesses.
- Wherever practicable, incorporate measures for non-motorised users, incorporating the ‘Trunk Road Cycling Initiative’.
- Maintain the asset value of the A75 Trunk Road.
- Mitigate the environmental impact of the new works where possible.
- Achieve good value for money for both taxpayers and transport users.