A4 Bristol to East Keynsham Corridor Study - Option Assessment Report Prepared for West of England Combined Authority May 2018 1 The Square Temple Quay Bristol BS1 6DG Document history A4 Bristol to East Keynsham Corridor Study Option Assessment Report This document has been issued and amended as follows: Version Date Description Created by Verified by Approved by 1.0 Jan 2018 Draft for client review VE DJL DJL (chapters 1 – 7) 2.0 March Draft for client review VE DJL DJL 2018 (inc EAST assessment) 3.0 May 2018 FINAL DL DL Contents Section Page Acronyms and Abbreviations ............................................................................................................... i 1 Introduction .......................................................................................................................... 1 1.1 Purpose of this report ......................................................................................................... 1 1.1.1 Description of the Study ........................................................................................ 1 1.2 Strategic Context ................................................................................................................ 3 There are several important strategic policies that have informed the development of the proposals described in this report. These are identified below. ..................... 3 1.2.1 National Planning Policy Framework ..................................................................... 3 1.2.2 Joint Spatial Plan and Local Plans .......................................................................... 3 1.2.3 Joint Local Transport Plan ...................................................................................... 4 1.2.4 Relationship with Transport Topic Paper .............................................................. 5 1.2.5 Approach to Options Assessment Reports ............................................................ 5 1.2.6 Structure of this report .......................................................................................... 5 2 Understanding the Current Situation ...................................................................................... 7 2.1 Description of the Study Area ............................................................................................. 7 2.1.1 General................................................................................................................... 7 2.1.3 Constraints - General ............................................................................................. 8 2.1.4 Physical constraints ............................................................................................... 8 2.1.5 Environmental constraints ..................................................................................... 9 2.1.6 Non-car modes..................................................................................................... 10 2.2 Current Vehicle Demands ................................................................................................. 11 2.3 Existing Transport Problems ............................................................................................. 13 2.3.1 Wider connectivity challenges in Keynsham ....................................................... 14 3 Understanding the Future Transport Situation ...................................................................... 16 3.1 Future Land Uses and Policies .......................................................................................... 16 3.1.1 Committed developments ................................................................................... 16 3.1.2 JSP proposals........................................................................................................ 17 3.2 Future Changes to the Transport System ......................................................................... 19 3.2.1 Keynsham Transport Strategy.............................................................................. 19 3.2.2 West of England Joint Transport Study ............................................................... 21 3.3 Future Traffic Demand ...................................................................................................... 22 3.4 Future Transport Related Problems ................................................................................. 24 3.4.1 Base-line Modelling (2029) .................................................................................. 24 3.4.2 Connectivity from the North Keynsham SDL ....................................................... 24 3.4.3 Requirement for improved connectivity from Broadmead to A4 ....................... 25 4 Need for Intervention, Objectives and Geographical Scope ................................................... 26 4.1 Summary of Current and Future Problems, Impacts and Outcomes ............................... 26 4.2 Scheme Objectives and Outcomes ................................................................................... 26 4.3 Measures for Success ........................................................................................................ 26 5 Generating and Initial Sifting of Options ............................................................................... 28 5.1 Approach to Option Generation ....................................................................................... 28 SECTION PAGE 5.2 Results of Option Generation ........................................................................................... 28 5.3 Approach to Initial Option Sifting ..................................................................................... 30 5.4 Results of Initial Sifting ..................................................................................................... 31 6 Option Development and Assessment .................................................................................. 35 6.2 Option Development ........................................................................................................ 36 6.2.1 Option 2A - ‘Pixash to Avon Mill Lane’ ................................................................ 36 6.2.2 Option 2C - ‘Pixash to new junction on A4175’ ................................................... 38 6.2.3 Option 3A - ‘A4 new junction to Avon Mill Lane’ ................................................ 40 6.2.4 Option 3C - ‘A4 new junction to new junction on A4175’ ................................... 41 6.3 Construction Access .......................................................................................................... 42 6.4 Traffic Modelling ............................................................................................................... 43 6.5 Cost Estimating and Economic Assessment ...................................................................... 46 6.5.1 Cost Estimating .................................................................................................... 46 6.5.2 Economic Assessment .......................................................................................... 47 7 TAG Appraisal Stage 1- Early Assessment and Sifting Tool Tables ........................................... 48 7.1 Introduction ...................................................................................................................... 48 8 Early Assessment and Sifting Tool - Supporting Information .................................................. 53 8.1 Strategic Case .................................................................................................................... 53 8.1.1 Scale of Impact ..................................................................................................... 53 8.1.2 Fit with wider transport and government objectives .......................................... 54 8.1.3 Fit with scheme objectives .................................................................................. 55 8.1.4 Key uncertainties ................................................................................................. 56 8.1.5 Degree of consensus over outcomes ................................................................... 57 8.1.6 Summary of strategic case ................................................................................... 57 8.2 Economic Case .................................................................................................................. 57 8.2.1 Economic growth ................................................................................................. 57 8.2.2 Carbon emissions ................................................................................................. 60 8.2.3 Local environment ............................................................................................... 60 8.2.4 Socio-distributional and regionals impacts .......................................................... 63 8.2.5 Well being ............................................................................................................ 64 8.2.6 Value for Money .................................................................................................. 64 8.2.7 Summary of economic case ................................................................................. 65 8.3 Managerial Case ................................................................................................................ 65 8.3.1 Implementation Timetable .................................................................................