A303 Stonehenge Amesbury to Berwick Down Technical Appraisal Report Volume 1
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A303 Stonehenge Amesbury to Berwick Down Technical Appraisal Report Volume 1 Public Consultation 2017 A303 Amesbury to Berwick Down | HE551506 Table of contents Chapter Pages Executive summary 1 Purpose of report 1 Problems and opportunities 1 Scheme objectives 2 Options identification 2 Initial Corridor appraisal – Design Fix A 2 Development of route options within corridors – Design Fix B 5 Initial route options appraisal – Design Fix C 6 Further route options appraisal 9 Appraisal summary 14 Programme 14 Overall Summary 15 1 Introduction 16 1.1 Purpose of this report 16 1.2 Scheme context 16 1.3 Scheme history 18 1.4 Technical reports 27 1.5 Structure of the report 27 2 Planning brief 30 2.1 Introduction 30 2.2 Client Scheme Requirements 30 2.3 Expansion on headline requirements 30 3 Existing conditions 32 3.1 Engineering conditions 32 3.2 Environmental status 49 3.3 Environmental conditions 50 3.4 Social conditions 56 3.5 Distributional conditions 58 3.6 Maintenance and repair strategy statement 59 3.7 Other relevant factors 62 4 Planning context 64 4.1 Introduction 64 4.2 UK Legislation and European Directives 64 4.3 National policy 66 4.4 Other relevant policy and strategy 68 4.5 Local policy 70 5 Initial corridors appraisal 72 5.1 Introduction 72 5.2 Initial corridors identification and appraisal 72 A303 Amesbury to Berwick Down | HE551506 6 Development of route options within corridors 104 6.1 Introduction 104 6.2 Basis of geometric design 104 7 Initial route options appraisal 118 7.1 Introduction 118 7.2 Route option proposals for assessment 118 7.3 Appraisal methodology 118 7.4 Corridor D route options assessment 124 7.5 Corridor F route options assessment 133 7.6 Conclusions 144 8 Description of route options for further appraisal 145 8.1 Introduction 145 8.2 Route descriptions 145 8.3 Road layout 149 8.4 Highway design relaxations and departures from standards 150 8.5 Junction and side roads strategy 150 8.6 Carriageway lighting 153 8.7 Impact on existing utilities 153 8.8 Proposed structures 154 8.9 Public Rights of Way (PRoW) 155 8.10 Tunnel design with Route Options D061 and D062 155 8.11 Earthworks 157 8.12 Surface water drainage 158 8.13 Buildability 159 9 Client Scheme Requirements and policy assessment 162 9.1 Introduction 162 9.2 Assessment methodology 162 9.3 Assessment 163 9.4 Summary and conclusions 167 10 Traffic analysis and modelling 170 10.1 Introduction 170 10.2 Initial corridors appraisal (Design Fix A) traffic modelling 170 10.3 Initial route options appraisal (Design Fix C) traffic modelling 175 10.4 Further WebTAG appraisal traffic modelling 180 10.5 Road layout and standards 186 10.6 Conclusions 191 11 Economic assessment 194 11.1 Introduction 194 11.2 Overview 194 11.3 Presentation of results 196 11.4 Approach 196 11.5 Results – Typically monetised impacts (initial BCR) 208 11.6 Results – Other transport and economic impacts (adjusted BCR) 209 HE551506-AA-GEN-SWI-RP-CX-000020 |P13, S0| 21/12/2016 A303 Amesbury to Berwick Down | HE551506 11.7 Results – Other Monetised Impacts 209 11.8 Results – supplementary approach to wider economic benefits 210 11.9 Sensitivity Tests 210 11.10 Programmatic Appraisal 211 11.11 Economic assessment conclusions 212 12 Social assessment 215 12.1 Introduction 215 12.2 Assessment methodologies 215 12.3 Assessment 220 12.4 Conclusions 224 13 Distributional impact assessment 226 13.1 Introduction 226 13.2 Assessment methodology 227 13.3 Assessment 228 14 Safety assessment 234 14.1 Introduction 234 14.2 Impact on road user 234 14.3 Impact during construction, maintenance, operation and demolition (CDM) 241 15 Operational assessment 243 15.1 Introduction 243 15.2 Schemes operating regime 243 15.3 Driver compliance 245 15.4 Conclusion 245 16 Technology assessment 246 16.1 Introduction 246 16.2 Option design implications of ITS systems 246 16.3 Regional Control Centre systems and sub systems 247 16.4 Conclusion 248 17 Maintenance assessment 249 17.1 Introduction 249 17.2 Maintenance and repair strategy for civils 249 17.3 Maintenance and repair strategy for technology 250 17.4 Conclusion 250 18 Environmental assessment 252 18.1 Introduction 252 19 Stakeholder engagement 268 20 Appraisal summary 277 20.1 Introduction 277 20.2 Appraisal Summary Tables (ASTs) 281 21 Programme 284 21.1 Introduction 284 21.2 Key milestones 284 HE551506-AA-GEN-SWI-RP-CX-000020 |P13, S0| 21/12/2016 A303 Amesbury to Berwick Down | HE551506 22 Overall Summary 285 GLOSSARY 288 GLOSSARY DESCRIPTIONS 292 Appendix A Existing conditions 303 A.1 Existing features 304 A.2 Existing public utilities 305 A.3 Existing geology mapping 306 A.4 Existing traffic, journey time and accident data 307 A.5 Environmental constraints 308 Appendix B Initial corridors appraisal (Design Fix A) 309 B.1 Historical routes 310 B.2 Corridors identified 311 B.3 Environmental assessment methodology and scoring assessment 312 B.4 Client Scheme Requirements 313 B.5 Environmental NPSNN assessment 314 B.6 EAST assessment 315 B.7 Better performing corridors 316 Appendix C Development of route options within preferred corridors (Design Fix B) 317 C.1 Corridor D with historic routes 318 C.2 Corridor D rationalised route options 319 C.3 Corridor D route options for initial appraisal 320 C.4 Corridor F with historic routes 321 C.5 Corridor F rationalised route options 322 C.6 Corridor F historic route rationalisation table 323 C.7 Corridor F refined route options 327 C.8 Corridor F route options for initial appraisal 328 Appendix D Initial route option assessment (Design Fix C) 329 D.1 Initial route option assessment (Design Fix C) 330 Appendix E Route options for further appraisal 331 E.1 Route options for further appraisal (D001, D003 and F010) 332 E.2 Intermediate route options (D031, D032 and F010) 333 E.3 Amended route options for further appraisal (D061, D062 and F010) 334 Appendix F Description of route options for further appraisal 335 F.1 Route Option D061 proposed layout 336 F.2 Route Option D062 proposed layout 337 F.3 Route Option F010 proposed layout 338 Appendix G Client Scheme Requirements and policy assessment 339 G.1 Client Scheme Requirements and policy assessment 340 Appendix H Assessment summary 341 H.1 Appraisal summary tables 342 HE551506-AA-GEN-SWI-RP-CX-000020 |P13, S0| 21/12/2016 A303 Amesbury to Berwick Down | HE551506 Table of Figures Figure 1 Options identification process ...................................................................... 2 Figure 2 Better performing corridor options (Design Fix A) ........................................ 5 Figure 3 Corridor D route options for initial appraisal ................................................. 7 Figure 4 Corridor F route options for initial appraisal ................................................. 9 Figure 5 Route options for further appraisal ..............................................................10 Figure 1-1 A303/A30 trunk route and Amesbury to Berwick Down scheme ...........16 Figure 1-2 Schemes to deliver an Expressway to the South West ........................18 Figure 1-3 Examples of alternative routes considered ...........................................20 Figure 1-4 Scheme published in 2003 for A303 Stonehenge Improvement ..............23 Figure 1-5 Plan showing location of relocated Stonehenge Visitor Centre ............25 Figure 1-6 Highways England's Project Control Framework structure ......................27 Figure 3-1 A303 Amesbury to Berwick Down scheme assessment area ...............32 Figure 3-2 Proximity of Stonehenge to the A303 ...................................................33 Figure 3-3 Climate graph – Boscombe Down ............................................................35 Figure 3-4 Distribution of traffic on the A303 at Stonehenge .....................................43 Figure 3-5 A303 – Westbound daily traffic by day and month ...................................44 Figure 3-6 A303 – Eastbound daily traffic by day and month ....................................44 Figure 3-7 A303 through traffic (between Hampshire border and Winterbourne Stoke) ..................................................................................................................................46 Figure 3-8 Accident section locations ........................................................................48 Figure 3-9 Accident sections between Amesbury to Berwick Down ..........................49 Figure 5-1 Options identification process ..................................................................72 Figure 5-2 Corridor A - Surface routes more than 1km north of A303 (outside WHS) ..................................................................................................................................75 Figure 5-3 Corridor B - Surface routes more than 1km north of A303 (at least partially within WHS) ..............................................................................................................76 Figure 5-4 Corridor C - Surface routes within 1.0 km of the existing A303 (at least partially within WHS) .................................................................................................77 Figure 5-5 Corridor D - Partially tunnelled route options within 1.0km (on plan) of the existing A303 (partially within WHS)..........................................................................78 Figure 5-6 Corridor E - Surface routes and more than 1km south of A303 (at least partially within WHS) .................................................................................................79 Figure