Transportation Transport Scotland March 2013 A9 Keir Roundabout to West of Broxden Roundabout Corridor Study - DMRB Stage 1 Route Study Assessment Report Table of Contents 1 Introduction ....................................................................................................................................................................... 4 1.1 Introduction ............................................................................................................................................................ 4 1.2 Background ........................................................................................................................................................... 4 1.2.1 STPR 16 – A9 Upgrading from Dunblane to Inverness ......................................................................................... 4 1.2.2 Infrastructure Investment Plan ............................................................................................................................... 4 1.3 Study Objectives .................................................................................................................................................... 5 1.3.1 National Transport Strategy ................................................................................................................................... 5 1.3.2 STPR Intervention 16 Objectives ........................................................................................................................... 5 1.3.3 Study Objectives .................................................................................................................................................... 5 1.4 The Project Brief .................................................................................................................................................... 5 2 Existing Conditions........................................................................................................................................................... 6 2.1 Introduction ............................................................................................................................................................ 6 2.2 Background ........................................................................................................................................................... 6 2.3 Route Description .................................................................................................................................................. 7 2.4 Existing Traffic Conditions ..................................................................................................................................... 7 2.4.1 Introduction ............................................................................................................................................................ 7 2.4.2 Traffic Flows .......................................................................................................................................................... 7 2.4.3 Congestion .......................................................................................................................................................... 15 2.4.4 Safety .................................................................................................................................................................. 15 2.4.5 Non-Motorised Users ........................................................................................................................................... 21 2.4.6 Public Transport Network .................................................................................................................................... 22 2.5 Future Conditions ................................................................................................................................................ 24 2.6 Existing Road Network ........................................................................................................................................ 27 2.6.1 Alignment ............................................................................................................................................................. 27 2.6.2 Junctions ............................................................................................................................................................. 27 2.6.3 Roadside Features .............................................................................................................................................. 31 2.6.4 Cross Section ...................................................................................................................................................... 32 2.7 Other Potential/Proposed Improvements ............................................................................................................. 34 2.8 Existing Environmental Conditions ...................................................................................................................... 34 2.8.1 Air Quality ............................................................................................................................................................ 34 2.8.2 Cultural Heritage .................................................................................................................................................. 34 2.8.3 Landscape ........................................................................................................................................................... 35 2.8.4 Ecology and Nature Conservation ....................................................................................................................... 37 2.8.5 Geology & Soils ................................................................................................................................................... 38 2.8.6 Noise and Vibration ............................................................................................................................................. 38 2.8.7 Community and Private Assets ............................................................................................................................ 39 2.8.8 Road Drainage and the Water Environment ........................................................................................................ 43 3 Route Strategies and Options ........................................................................................................................................ 48 3.1 Introduction .......................................................................................................................................................... 48 3.2 Grade Separation of Keir Roundabout ................................................................................................................. 48 3.3 Alternative Strategies for Grade Separation between Keir Roundabout and Broxden Roundabout .................... 48 3.3.1 Collisions ............................................................................................................................................................. 49 3.3.2 Strategy 1: Do Minimum ...................................................................................................................................... 49 3.3.3 Dual Carriageway Categorisation ........................................................................................................................ 50 3.3.4 Strategy 2: Roundabouts to facilitate u-turning traffic .......................................................................................... 50 3.3.5 Strategy 3: Grade separation of junctions ............................................................................................................ 51 3.4 Additional Options for Grade Separation ............................................................................................................. 58 3.4.1 A824 Auchterarder/Loaninghead Interchange Link ............................................................................................. 58 3.4.2 Shinafoot ............................................................................................................................................................. 59 3.5 Other Minor Roads/Accesses .............................................................................................................................. 59 3.6 Alternative Strategy Conclusions ......................................................................................................................... 59 4 Engineering Assessment ............................................................................................................................................... 60 4.1 Introduction .......................................................................................................................................................... 60 4.2 Locations considered for grade separation .......................................................................................................... 60 4.3 Keir Roundabout .................................................................................................................................................. 61 4.3.1 Site Description.................................................................................................................................................... 61 4.3.2 Topography and