Tandridge District Council Local Plan Document Title: Strategic Highway
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S TANDRIDGE DISTRICT COUNCIL LOCAL PLAN Strategic Highway Assessment Report Project Title: Tandridge District Council Local Plan Document Title: Strategic Highway Assessment Report Client Reference: Date: 12th November 2015 Prepared By: Print William Bryans Authorised By: Print All maps contained in this document are licensed © Crown copyright and database rights 2015 Ordnance Survey 100019613 Amendment List Iss. / Rev. Iss. / Rev Remove Insert Date Page Iss. / Rev. Page Iss. / Rev. 2 13/10 3 12/11 0201SF10 07/08/02 Filename: S:\Project-Current\3613\53613T37_Tandridge Local Plan\05 Reports\Doc01_Strategichighwayassessmentreport_V5.Doc Issue No. 03 Page 2 Document No. 53613TS37 / 01 Tandridge District Council Local Plan Strategic Highway Assessment Report CONTENTS EXECUTIVE SUMMARY 1 INTRODUCTION 6 1.1 Overview 6 1.2 Objectives 6 2 STRATEGIC TRANSPORT MODEL 7 2.1 Model and Scope 7 2.2 Base Year 8 2.3 Modes of Transport 8 2.4 Time Periods 8 2.5 Study Area and Zones 8 3 MODEL FORECASTING, TRIP GENERATION AND TRIP DISTRIBUTION10 3.1 Forecast Year 10 3.2 Forecast Scenarios 10 3.3 Development Sites and Pro-Forma 13 3.4 Vehicle Trip Generation 13 3.5 External and Background Traffic Growth 18 3.6 Vehicle Trip Distribution 18 3.7 Forecast Network 19 3.8 Assignment 19 4 MODEL RESULTS AND ANALYSES 20 4.1 Overview 20 4.2 Network Statistics 22 4.3 Level of Service (LOS) 24 4.4 Ratio of Flow to Capacity (RFC) 24 4.5 Increase in Flow 25 4.6 Changes in Capacity and Level of Service 33 4.7 Motorways & Trunk Roads 35 4.8 Increase in Junction Delay 36 4.9 Journey Times along Key Routes 46 4.10 Cross Boundary Impacts 50 5 SUMMARY 53 APPENDICES 55 Issue No. 03 Page 3 Document No. 53613TS37 / 01 Tandridge District Council Local Plan Strategic Highway Assessment Report EXECUTIVE SUMMARY Surrey County Council was commissioned by Tandridge District Council to undertake highway modelling to assist in the provision of an evidence base for the emerging Local Plan. The Tandridge District Council Local Plan Strategic Highway Assessment is a strategic transport modelling study that aims to inform the decision making surrounding the suitability of potential development sites. It should be noted that the scenarios tested and analysed for this report were generated from statistics that at the time were still being identified from the council’s Housing and Economic Land Availability Assessment (HELAA) and may not reflect the final findings of the HELAA. This document sets out details of the transport model (SINTRAM), the forecasting methodology, as well as the results and analysis of the traffic impacts of the potential development sites. The main objectives were to: calculate the number and distribution of vehicle trips based on the quantum and locations of additional commercial and residential development in various growth scenarios from the data provided by Tandridge District Council; forecast the traffic impacts of various development scenarios; act as a starting point for identifying the locations that may require further investigation regarding traffic impacts; and report the main traffic impacts. This report does not go onto identify and recommend potential mitigation. This would need to be done at a later stage, but in advance of any Examination in Public. However, this report would act as a useful starting point for undertaking this work. A future year do-minimum reference and five do-something scenarios were tested: 2031 do-minimum scenario 1 includes all commercial and residential development sites that have received planning permission within the district of Tandridge since 2009; 2031 do-something scenario 2a contains all of the sites in scenario 1 with the addition of all the most likely Local Plan development sites; 2031 do-something scenario 2b is the same as scenario 2a, but the Local Plan development sites are assumed to be of higher density; 2031 do-something scenario 3 contains all of the sites in scenario 2a with additional commercial development and additional residential development focused on Caterham (including Caterham hill and Caterham Valley), Whyteleafe, Warlingham Oxted (including Limpsfield), Smallfield, Lingfield and Godstone; 2031 do-something scenario 4 contains all of the sites in scenario 2a with additional commercial development (as in scenario 3) and additional residential development focused on Bletchingley, Woldingham, South Nutfield, Dormansland, South Godstone, Tatsfield, Blindley Heath, Limpsfield Chart, Nutfield, Felbridge, Old Oxted; and 2031 do-something scenario 5 contains all of the sites in scenario 2a with additional commercial development (as in scenarios 3 and 4) and the additional residential development that is also in scenarios 3 and 4. Of the five do-something scenarios, scenario 2b is projected to generate the smallest traffic impacts on the highway network in Tandridge. Although this scenario represents an Issue No. 03 Page 4 Document No. 53613TS37 / 01 Tandridge District Council Local Plan Strategic Highway Assessment Report intensification of the development proposed in Scenario 2a (an additional 175 dwellings and the same amount of commercial development), the proposed residential development consists of a greater number of flats. However, the total number of new vehicle trips generated in scenario 2b is lower than in scenario 2a because the trip rate associated with flats is lower when compared with that for houses. Scenarios 2a and 2b are forecast to generate similar impacts on the district’s highway network when considering general network traffic statistics. Scenario 4 is also forecast to have relatively moderate effects on the network. In all of these scenarios, the impacts are most marked in the north of the district, including Oxted and Hurst Green, Godstone, Caterham and Warlingham. Scenarios 3 and 5 are forecast to have the greatest impacts, both in the south and north of the district, including Smallfield, Caterham. In some locations effects are expected to be experienced some distance from proposed development locations reflecting the potential cumulative impacts on existing roads and junctions. This includes some impacts across the boundary, especially to in the north east and in the south and south-west of the district. There are forecast to be limited numbers of trips added to the motorway network, although re-routing as a result of additional trips on the network does affect motorway flows. However, parts of the motorway network in the area are forecast to be either approaching or already operating overcapacity by 2031 so any additional trips may have more of a significant effect. Issue No. 03 Page 5 Document No. 53613TS37 / 01 Tandridge District Council Local Plan Strategic Highway Assessment Report 1 INTRODUCTION 1.1 Overview 1.1.1 Tandridge District Council is currently in the process of developing their Local Plan to ensure future growth is facilitated within the district. To assist with the review of the district’s development scenarios Surrey County Council has been commissioned by the district council to undertake highway modelling to aid the evidence base of their Local Plan. The Tandridge District Council Local Plan Strategic Highway Assessment is a strategic transport modelling study that aims to inform the decision making surrounding the suitability of development sites which have been identified. 1.1.2 The assessment made use of Surrey County Council’s strategic transport model, SINTRAM. 1.1.3 This document sets out details of the transport model, the forecasting methodology, as well as the results and analysis of the traffic impacts of the potential development sites. 1.1.4 This study does not consider aspects such as: accessibility to facilities and services by either car or non-car modes from the potential development sites; the impact on existing public transport services such as passenger over- crowding and possible delays to services as a result of increased traffic congestion; what opportunities there might be for reducing the number of car trips to and from the potential new developments by the enhancement of sustainable transport facilities and services; what highway mitigation might be required to address the identified impacts. Accessibility issues and impacts on public transport services might have to be considered in separate pieces of work. The consideration of increasing sustainable travel and identifying highway mitigation would need to be done at a later stage, potentially to support a Regulation 19 submission to the Secretary of State and certainly in advance of any Examination in Public. However, this report acts as a useful starting point for undertaking such work. 1.2 Objectives 1.2.1 The purpose of this study was to evaluate the highway impacts of the developments contained within the forecast scenarios as developed by Tandridge District Council. 1.2.2 The main objectives of the study were to: calculate the number and distribution of vehicle trips based on the quantum and locations of additional commercial and residential development in various growth scenarios from the data provided by Tandridge District Council; forecast the traffic impacts of various development scenarios; act as a starting point for identifying the locations that may require further investigation regarding traffic impacts; and report the main traffic impacts. Issue No. 03 Page 6 Document No. 53613TS37 / 01 Tandridge District Council Local Plan Strategic Highway Assessment Report 2 STRATEGIC TRANSPORT MODEL 2.1 Model and Scope 2.1.1 Surrey County Council’s strategic transport model, SINTRAM version 6 (SINTRAM6_0_22_Tandridge_040915) was used for the assessment, with OmniTRANS modelling program, version 6.0.22. 2.1.2 SINTRAM is a strategic highway model for the county of Surrey. The model encapsulates the road network of Surrey and surrounding local authorities. Figure 2.1 presents the entire model area. Figure 2.1: Model extent 2.1.3 All motorways, A and B roads, together with most local roads are represented within SINTRAM. Where traffic junctions and traffic signals have a significant effect in terms of delay or route choice, details of their layout and/or timing of the signals have been included in the model.