Assessment of alternatives

Alternatives Studies

As described in the Scheme Background section of this chapter, the proposed scheme is being progressed based upon the findings and recommendations of a number of previous studies including STPR2 and SWestrans RTS. A full review of these studies is included in the A75 Strategic Assessment Report.

The SWestrans RTS considered multi-modal improvements on key strategic corridors in the south-west, with a particular focus on access to the ports at Cairnryan. STPR2 lists 45 recommendations for transport improvements across all regions of Scotland and across all modes. Through these previous studies a consideration of alternatives has been undertaken. Further detail of the previous studies can be found in the A75 Strategic Assessment Report.

Do Minimum Scenario

While the approach to the DMRB Stage 1 Assessment focusses on major improvements along the A75 in the vicinity of Springholm and Crocketford, it is also necessary to consider the “Do-Minimum” scenario in the quantitative assessment, including economic appraisal, against which the proposed scheme is compared.

The Do-Minimum scenario reflects the most likely transport situation where the proposed scheme is not progressed and no major intervention is assumed to occur. The current road layout is largely maintained as is, with essential road maintenance continuing to be addressed and minor interventions undertaken. This allows the assessment to determine the potential impacts of not progressing the proposed scheme and allows a consistent baseline comparison against which the effects of the proposed scheme can be determined.

Examples of these potential interventions that could be anticipated in the Do-Minimum scenario include improvements to the safety and operation of the route such as updated signing and lining, the installation of additional Variable Message Signs (VMS).