A9 Dualling Programme Strategic Environmental Assessment Non-Technical Summary
7. Material Assets
SEA Challenges/ Opportunities
A9 dualling presents a significant opportunity for the improvement of a regional (and national) material asset; however, the challenge is the consideration of dualling effects on material resources, other corridor infrastructure and the other SEA topics (inter-relationships).
SEA considers that online dualling will minimise material consumption through retained use of existing infrastructure; leading to potentially moderate adverse effects in terms of consumption of local material resources and the associated embodied carbon footprint. Alternative routes and offline dualling would increase consumption and carbon effects.
Use of local material suppliers would likely provide local population benefits and help to minimise the overall footprint in terms emissions associated with material transportation.
A9 dualling infrastructure will be designed to comply with the Design Manual for Roads and Bridges (DMRB) standards and revised to reflect relevant DMRB updates between outline/ detailed design and construction stages.
DMRB requires a phased design process with progressively more detailed environmental assessment to inform:
- DMRB 1 - broad corridor selection, generally informed by desk based identification of constraints and issues (SEA is collating this information);
- DMRB 2 - comparison of a range of alternative route alignments within the preferred corridor, informed by local environmental surveys;
- DMRB 3 - detailed design of a preferred route, with more detailed site level survey and environmental assessment to inform design level mitigation and enhancement measures.
The SEA assumes compliance with DMRB standards across all A9 dualling route alignment studies and detailed design delivery stages.
|Infrastructure features in the A9 dualling corridor|
|Highland mainline railway between Perth and Inverness|
|Existing power supply lines|
|Sections of the proposed route and some tower locations for the Beauly-Denny Line grid infrastructure project|
|3 wind farms (2 planned, 1 operational) within 1km of the current A9 route|
|Local planning authority Development Plan allocations|
A project to consider improvements to the Highland Mainline railway is in development. SEA recommends that the A9 dualling programme tracks the development of this project to ensure any cumulative issues are identified and managed.
The Beauly-Denny line crosses the A9 around the Glen Garry, Drumochter Hills and Glen Truim areas. SEA recommends a more detailed assessment around the Drumochter Hills area as part of an Appropriate Assessment to consider the potential cumulative issues.
Online dualling is not expected to significantly affect current development plans, as these have been developed with consideration to the current A9. A9 dualling is also not expected to present significant cumulative issues with wind farm proposals, although SEA recommends further assessment at the local design level.
SEA recommends further work, during the Environmental Report consultation period, to review the emerging A9 dualling Junction Strategy, Lay By Strategy and Non-Motorised Users Strategy and to develop strategic principles on lighting and signage, cuttings, barriers and structures.
Further consideration of these elements will inform a set of strategic environmental and design principles, for inclusion with the SEA Post Adoption Statement.
The ultimate aim is for the SEA and Preliminary Engineering work to inform an overarching A9 Design Guide to support route wide consistency.