Hertfordshire COMET: Local Plan Forecasting Report - LTP4 FINAL DRAFT Project number: 60588905 June 2019 Hertfordshire COMET: Local Plan Forecasting Report Project number: 60555331 Quality information Prepared by Checked by Approved by PNG, TTS CW SK Revision History Revision Revision date Approved by Draft for comment 03 May 2019 SK Final incorporating HCC Comments 05 June 2019 SK FINAL DRAFT 2 AECOM Hertfordshire COMET: Local Plan Forecasting Report Project number: 60555331 Prepared for: Hertfordshire County Council Prepared by: AECOM Limited AECOM House 63-77 Victoria Street St Albans Hertfordshire AL1 3ER United Kingdom T: +44(0)1727 535000 aecom.com FINAL DRAFT © 2019 AECOM Limited. All Rights Reserved. This document has been prepared by AECOM Limited (“AECOM”) for sole use of our client (the “Client”) in accordance with generally accepted consultancy principles, the budget for fees and the terms of reference agreed between AECOM and the Client. Any information provided by third parties and referred to herein has not been checked or verified by AECOM, unless otherwise expressly stated in the document. No third party may rely upon this document without the prior and express written agreement of AECOM. 3 AECOM Hertfordshire COMET: Local Plan Forecasting Report Project number: 60555331 Table of Contents 1. Executive Summary ............................................................................................ 7 1.1 Background to the Forecast ..................................................................................................... 7 1.2 Highway Network Results ......................................................................................................... 9 1.3 Public Transport Network Results .......................................................................................... 13 2. Introduction ....................................................................................................... 14 2.1 Background ............................................................................................................................. 14 2.2 Purpose of this Document ...................................................................................................... 15 2.3 Caveats ................................................................................................................................... 15 2.4 Previous Local Plan COMET Forecasting .............................................................................. 16 2.5 Report Structure ..................................................................................................................... 17 3. Forecast Approach ........................................................................................... 18 3.1 Forecast Objectives ................................................................................................................ 18 3.2 Model Years ............................................................................................................................ 18 3.3 Treatment of Variable Demand ............................................................................................... 18 3.4 Model Structure ...................................................................................................................... 18 4. Forecast Network Development ...................................................................... 20 4.1 Public Transport Network........................................................................................................ 20 4.2 Highway Network .................................................................................................................... 24 4.3 Road Traffic Forecasts 2018 (RTF 2018) ............................................................................... 27 5. Forecast Trip Matrix Development .................................................................. 31 5.1 Overview ................................................................................................................................. 31 5.2 COMET Trip End Model .......................................................................................................... 31 5.3 Forecast Planning Data .......................................................................................................... 35 5.4 Model Development Zones ..................................................................................................... 42 5.5 Variable Demand Modelling .................................................................................................... 45 5.6 Economic Parameters ............................................................................................................ 46 5.7 Forecast Growth Rates ........................................................................................................... 47 6. Forecast Assignments ...................................................................................... 49 6.1 Highway Assignment .............................................................................................................. 49 6.2 Public Transport Assignment .................................................................................................. 50 7. Highway Forecast Results ............................................................................... 51 7.1 Simulation Area Statistics ....................................................................................................... 51 7.2 Traffic Flows ............................................................................................................................ 55 7.3 Network Stress and Delays .................................................................................................... 59 7.4 Inter-urban Journey Times ...................................................................................................... 72 8. Public Transport Forecast Results .................................................................. 78 8.1 HertfordshireFINAL Statistics ................................ ................................DRAFT............................................ 78 9. Summary and Discussion ................................................................................ 86 9.1 Summary ................................................................................................................................ 86 9.2 Discussion .............................................................................................................................. 86 10. Appendices ....................................................................................................... 88 10.1 Appendix I: Employment Densities used for Calculation of Jobs ........................................... 88 10.2 Appendix II: SATURN Highway Assignment Parameters ....................................................... 90 10.3 Appendix III: Full List of Highway Schemes ........................................................................... 93 10.4 Appendix IV: Highway Simulation Area Statistics by User Class ......................................... 107 4 AECOM Hertfordshire COMET: Local Plan Forecasting Report Project number: 60555331 Figures Figure 1-1: Flow Difference on Key Corridors (2036 AM Peak minus 2014 AM Peak) ........................ 10 Figure 1-2: Volume over Capacity on Key Links (2036 AM Peak) ........................................................ 10 Figure 1-3: Delay at Key Junctions (2036 AM Peak) ............................................................................ 11 Figure 3-1: COMET Model Structure .................................................................................................... 19 Figure 4-1: Modal Shift Zones ............................................................................................................... 28 Figure 5-1: Change in numbers of dwellings 2014-2036 by COMET model zone (wider zoom) ......... 38 Figure 5-2: Change in numbers of dwellings 2014-2036 by COMET model zone (HCC zoom) .......... 38 Figure 5-3: Change in numbers of jobs 2014-2036 by COMET model zone (wider zoom) .................. 41 Figure 5-4: Change in numbers of jobs 2014-2036 by COMET model zone (HCC zoom)................... 41 Figure 5-5: Model Development Zone Selection Process .................................................................... 43 Figure 5-6: Model Development Zones (only shows sites that have a location allocated) ................... 43 Figure 7-1: Travel Distance (Simulation Area only)............................................................................... 53 Figure 7-2: Total Travel Time (Simulation Area only) ............................................................................ 53 Figure 7-3: Average Speed (Simulation Area only) ............................................................................... 54 Figure 7-4: Queues (Simulation Area only) ........................................................................................... 54 Figure 7-5: 2036 AM Peak Flow minus 2014 AM Peak (Key Links) ..................................................... 56 Figure 7-6: 2036 AM Peak Flow minus 2014 AM Peak (All Links)........................................................ 56 Figure 7-7: 2036 Inter-peak Flow minus 2014 Inter-peak (Key Links) .................................................. 57 Figure 7-8: 2036 Inter-peak Flow minus 2014 Inter-peak (All Links) .................................................... 57 Figure 7-9: