Evaluation of Transport Impacts
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South Bucks District Council Core Strategy Evaluation of Transport Impacts June 2010 Notice This document and its contents have been prepared and are intended solely for South Bucks District Council’s information and use in relation to the South Bucks Core Strategy. Atkins Limited assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents. Document History JOB NUMBER: 5064105 DOCUMENT REF: SBDC Transport Evaluation_revF.doc F Submitted Report LB LB HN HN 18/06/10 E Updated Report LB LB HN HN 14/06/10 D Final Report LB LB CPG CPG Feb 2010 C Draft Report LB - - - Feb 2010 B Draft Report LB - - - Feb 2010 A Draft Report LB LB CPG CPG Jan 2010 Revision Purpose Description Originated Checked Reviewed Authorised Date 5064105/SBDC Transport Evaluation_revF.doc Evaluation of Transport Impacts Contents Section Page Executive Summary 4 1. Introduction 6 Location 6 Report Structure 6 2. Baseline Conditions 7 Study Area 7 Highway Network 7 Transport Area Action Plans 12 Sustainable Modes of Travel 13 3. Policy Context and Review of Studies 17 National Level 17 Regional Level 19 Local Level 21 District Level – South Bucks District 24 DaSTS Study 26 4. Future Base Evaluation 27 5. South Bucks District Council Transport Evaluation 31 The Development Options 31 Impact on Highway Network 33 Mitigation Measures 36 Revised Impact Scenario with Mitigation Measures 40 Traffic Increases 43 Impact on Sustainable Modes of Travel 45 6. Conclusions and Recommendations 47 List of Tables Table 2.1 – Transport Area Action Plans Summary 12 Table 2.2 – Rail Services in South Bucks District 14 Table 2.3 – Bus Services in South Bucks District 15 Table 4.1 – Links that are Nearing or Over Capacity in the Future Base Scenarios (presented as a percentage of capacity) 27 Table 5.1 – Option 1 Housing Figures by Settlement 32 Table 5.2 – Option 2 Housing Figures by Settlement 32 Table 5.3 – Links Predicted to be Nearing or Over Capacity in 2026, Over and Above the Future Base Scenario 34 Table 5.4 – South Bucks Options – Potential Mitigation Measures 38 Table 5.5 – Links Predicted to be Nearing or Over Capacity in 2026, Over and Above the Future Base Scenario, with Mitigation Measures in Place 41 Table 5.6 – Flow Comparison Summary at Motorway Junctions – AM Peak Hour 44 Table 5.7 – Flow Comparison Summary at Motorway Junctions – PM Peak Hour 44 Table 5.8 –Multi Modal Total Two Way Person Trips for All Development Options 45 5064105/SBDC Transport Evaluation_revF.doc 2 Evaluation of Transport Impacts List of Figures No table of figures entries found. Appendices Appendix A 49 A.1 Road Network and Areas of Congestion 50 A.2 Sustainable Modes of Travel 51 Appendix B 52 Appendix C 53 Appendix D 54 5064105/SBDC Transport Evaluation_revF.doc 3 Evaluation of Transport Impacts Executive Summary South Bucks District Council has commissioned Atkins Transport Planning & Management to prepare an Evaluation of Transport Impacts (ETI) that will inform their emerging Core Strategy. The main objective of the ETI is to define and evaluate the transport impacts resulting from the potential development in the District and identify and exclude any options that would have an unacceptable impact on the road network, even with mitigation measures in place. In undertaking the ETI, Atkins has consulted with the Highways Agency (HA) and Buckinghamshire County Council (BCC) as well as working closely with South Bucks District Council (SBDC). The scope of the ETI, including the methodology and assumptions has been agreed with the Highways Agency at the project outset. The main body of this report covers an analysis of the baseline conditions, policy context and a review of studies as well as a summary of the evaluation in relation to Future Baseline conditions and the potential development in South Bucks District. Appendices to this report include figures supporting the evaluation. This report should be read in conjunction with the evaluation’s Report of Evidence, which describes the methodology and assumptions applied in the ETI as well as data and other evidence that supports it. A key element in the evaluation of development impact on transport infrastructure has been the analysis of road link capacities - a bespoke spreadsheet model has been created for this purpose. The ETI also includes multi-modal trip generation analyses and evaluation of impacts on sustainable modes of transport. The analysis of Baseline and Future Baseline conditions indicates that there is and will be significant pressure on existing transport infrastructure. Results of this analysis show that a number of links within the Study Area would be over capacity in the period of assessment even without considering the developments being evaluated. However it must be noted that a robust approach, following guidelines from the HA, has been applied where traffic growth factors have assumed a significant increase in background traffic growth due to population and economic growth. Two main development options, Option 1 and 2, have been assessed for South Bucks District which include different volumes of housing, based around broadly the same locations within the District. In addition, three sub-options for Option 2 have been assessed which include the opportunity sites being delivered as well as other key development areas. Conclusions from the evaluation generally highlight the importance of new development making use and optimising existing infrastructure. National, Regional and Local policies recommend that future development makes use of existing transport infrastructure as much as possible in order to avoid the reliance on the private car and encourage sustainable modes of transport. Conclusions from the evaluation indicate that the potential developments associated with the South Bucks Core Strategy will have an impact on the transport networks within the Study Area which will add to existing problems. However they are not shown to have a significant impact on the predicted capacity of the motorway links, including the slip roads, except at Junction 1 of the M40 where a large proportion of the additional traffic is a result of general background traffic growth. Infrastructure upgrades may be required at this location towards the end of the plan period and potential funding sources would need to be investigated. Due to the impact on the road network from development in South Bucks, mitigation measures to promote sustainable travel would be recommended. A revised highway impact scenario has been undertaken with a predicted mode shift away from the private car, which has been assessed to demonstrate the impact with mitigation measures in place. It is expected that mitigation measures would be required for all development options, especially with the background traffic growth taken account of as is the case in this analysis. These measures should focus on promoting travel by alternative means to the private car, through Travel Plans, with the focus towards making travel by sustainable transport modes more attractive than currently the case in the area. 5064105/SBDC Transport Evaluation_revF.doc 4 Evaluation of Transport Impacts The revised traffic impact assessment showed a small reduction in trips on all links including the Strategic Highway Network, therefore reducing the impact on capacities to a minimum extent. It is apparent that measures to improve highway capacity on the road network in South Bucks may be required in some locations, although this would require further work at the detailed planning application stage. Overall the conclusions from this analysis show that whilst Option 1 would be most preferable from a transport perspective, options 1-2b could be delivered without an unacceptable impact on the road network with appropriate mitigation in place. Option 2c would require further work to evaluate the impact of the development with the proposed mitigation measures included in the analysis. 5064105/SBDC Transport Evaluation_revF.doc 5 Evaluation of Transport Impacts 1. Introduction 1.1 South Bucks District Council has commissioned Atkins Transport Planning & Management to prepare an Evaluation of Transport Impacts (ETI) that will inform their emerging Core Strategy. 1.2 The Core Strategy Development Plan Document will set out the vision, objectives and strategy for development in the District in accordance with the South East Plan. It will plan for the period up to 2026 and set out policies and proposals to guide future development in the area, and provide a framework which planning applications can be assessed against. 1.3 This evaluation gives a greater understanding of the local transport movements and the effects of wider traffic movement on the Strategic Highway network in, and around the District. In summary the objectives of the project are as follows: • Define and evaluate the transport impacts due to the potential development in the District; • Evaluate the likely transport impacts of the proposals in the emerging core strategy; and • Identify and exclude any areas in which mitigation measures are undeliverable. 1.4 In undertaking the ETI, we have consulted the Highways Agency (HA) and Buckinghamshire County Council (BCC) as well as worked closely with both Chiltern District Council (CDC) and South Bucks District Council (SBDC). The scope of the ETI, as well as its methodology and assumptions has been agreed with the HA, who have collaborated in ensuring that a robust evaluation was undertaken. Location 1.5 South Bucks District is located in south Buckinghamshire, just south of Chiltern District. Slough and Maidenhead are located to the south and south west respectively, the London Borough of Hillingdon to the east, Wycombe District to the west and Aylesbury to the north-west. 1.6 The Study Area covers the whole area of both Chiltern and South Bucks Districts and strategic highway junctions serving the district areas as the study began as a joint one between the two councils.