wycombe district local plan - high wycombe area ... · document title: high wycombe area –...

Wycombe District Local Plan High Wycombe Area Transport Study January 2014

Wycombe District Local Plan - High Wycombe Area - Transport Study - Final.docx

Document Control Sheet BPP 04 F8 Version 16; October 2013

Project: Wycombe District Local Plan Client: Transport for Buckinghamshire Project No: B1279891/RE

Document title: High Wycombe Area – Transport Study Ref. No: WDLP/HWA/TS

Originated by Checked by Reviewed by

ORIGINAL NAME NAME NAME

Christine Paine Emily White Rich Smith

Approved by NAME As Project Manager I confirm that the above document(s) have been subjected to Jacobs’ Check and Review procedure and that I approve them for issue

INITIALS

Rich Smith

DATE 22/01/14 Document status: Draft

REVISION A NAME NAME NAME

Rich Smith Emily White Paul Smith


INITIALS

Rich Smith

DATE 31/01/14 Document status: Final

REVISION NAME NAME NAME


INITIALS

DATE Document status

Jacobs U.K. Limited This document has been prepared by a division, subsidiary or affiliate of Jacobs U.K. Limited (“Jacobs”) in its professional capacity as consultants in accordance with the terms and conditions of Jacobs’ contract with the commissioning party (the “Client”). Regard should be had to those terms and conditions when considering and/or placing any reliance on this document. No part of this document may be copied or reproduced by any means without prior written permission from Jacobs. If you have received this document in error, please destroy all copies in your possession or control and notify Jacobs.

Any advice, opinions, or recommendations within this document (a) should be read and relied upon only in the context of the document as a whole; (b) do not, in any way, purport to include any manner of legal advice or opinion; (c) are based upon the information made available to Jacobs at the date of this document and on current UK standards, codes, technology and construction practices as at the date of this document. It should be noted and it is expressly stated that no independent verification of any of the documents or information supplied to Jacobs has been made. No liability is accepted by Jacobs for any use of this document, other than for the purposes for which it was originally prepared and provided. Following final delivery of this document to the Client, Jacobs will have no further obligations or duty to advise the Client on any matters, including development affecting the information or advice provided in this document.

This document has been prepared for the exclusive use of the Client and unless otherwise agreed in writing by Jacobs, no other party may use, make use of or rely on the contents of this document. Should the Client wish to release this document to a third party, Jacobs may, at its discretion, agree to such release provided that (a) Jacobs’ written agreement is obtained prior to such release; and (b) by release of the document to the third party, that third party does not acquire any rights, contractual or otherwise, whatsoever against Jacobs and Jacobs, accordingly, assume no duties, liabilities or obligations to that third party; and (c) Jacobs accepts no responsibility for any loss or damage incurred by the Client or for any conflict of Jacobs’ interests arising out of the Client's release of this document to the third party.


Contents

1� Introduction 1�1.1� Purpose of Report 1�1.2� Background 1�1.3� Overview of Modelling Assessment 2�1.4� Structure of Report 3�

2� Policy and Document Review 5�2.1� Introduction 5�2.2� Policy Review 5�

3� Baseline Review 10�3.1� Introduction 10�3.2� Population Characteristics 10�3.3� Highway Network 11�3.4� Public Transport 19�3.5� Non-motorised Users 21�3.6� Summary 22�

4� High Wycombe Area in 2031 23�4.1� Introduction 23�4.2� Land Use 23�4.3� Highway Network 23�4.4� Public Transport 29�4.5� Non-motorised Users 30�4.6� Summary 30�

5� Land Use and Infrastructure Scenarios 31�5.1� Introduction 31�5.2� Land Use Developments 31�5.3� Transport Mitigation Packages 33�5.4� Sustainable Travel / Mode Shift 34�

6� Traffic Assessment and Appraisal 37�6.1� Introduction 37�6.2� Modelling Results - Do Something Scenario 37�6.3� Modelling Results - Do Something Mitigation Packages 43�6.4� Performance of Significant Schemes 48�6.5� Mitigation Package Appraisal 51�6.6� Summary 53�

7� Land North of Heath End Road (M40 Junction 3a) 54�7.1� Introduction 54�7.2� Land Use Development 54�7.3� Strategic Transport Mitigation 55�


7.4� Modelling Results – Land North of Heath End Road (M40 J3a) 56�7.5� Overall Network Performance 65�7.6� Mitigation Package Appraisal 65�7.7� Summary 67�

8� Summary and Conclusion 68�8.1� Overall Summary 68�8.2� Conclusion 69� Table 3-A� 2013 AM and PM peak modelled journey times 15�Table 3-B� Collision clusters at junctions in High Wycombe 2009-2011 18�Table 4-A� Journey time and speed 2031 Do Minimum 28�Table 5-A� 2031 land use development sites 31�Table 5-B� Trip rates from TRICS database by land use class 32�Table 5-C� Traffic generation from land use development sites 33�Table 5-D� Policy DM2 Transport Requirements 36�Table 6-A� Journey time and speed - 2031 Do Something 42�Table 6-B� M40 Handy Cross TRANSYT analysis – summary of results 43�Table 6-C� Network summary statistics 44�Table 6-D� PM Peak average trip length 46�Table 6-E� Type of junction serving land use sites in each scenario 46�Table 6-F� Summary appraisal table – mitigation packages 52�Table 7-A� 2031 land use development sites – Land North of Heath End

Rd 54�Table 7-B� Trip rate assumptions – Land North of Heath End Rd 54�Table 7-C� Traffic generation – Land North of Heath End Rd 55�Table 7-D� Two-way traffic volume differences with mitigation packages 60�Table 7-E� Key changes in junction delay – Land North of Heath End Rd 63�Table 7-F� Network summary statistics – Land North of Heath End Rd 65�Table 7-G� Summary appraisal table – Land North of Heath End Rd

mitigation packages 66� Figure 1-A� Study area 2�Figure 3-A� 2011 Census household vehicle ownership 10�Figure 3-B� 2011 Census main method of travel to work 10�Figure 3-C� Local highway network 11�Figure 3-D� 2013 AM peak modelled flows 12�Figure 3-E� 2013 PM peak modelled flows 13�Figure 3-F� 2013 AM base model trip distribution 13�Figure 3-G� 2013 PM peak through trips 14�Figure 3-H� Journey time routes 15�Figure 3-I� 2013 AM peak modelled link speeds and delay 16�Figure 3-J� 2013 PM peak modelled link speeds and delay 17�Figure 3-K� Outline of proposed High Wycombe AQMA 19�Figure 3-L� Summary of total entries and exits for High Wycombe station 20�Figure 3-M� High Wycombe Local Bus Routes 21�Figure 4-A� 2031 Do Minimum AM Peak modelled flows 24�Figure 4-B� 2031 Do Minimum PM Peak modelled flows 24�Figure 4-C� Change in AM peak traffic volumes between 2013 and 2031 25�Figure 4-D� Change in PM peak traffic volumes between 2013 and 2031 25�Figure 4-E� 2031 Do Minimum AM peak link speeds and delay 27�


Figure 4-F� 2031 Do Minimum PM peak link speeds and delay 27�Figure 5-A� Land use development site locations 32�Figure 6-A� 2031 Do Something (unmitigated) AM peak modelled flows 38�Figure 6-B� 2031 Do Something (unmitigated) PM peak modelled flows 38�Figure 6-C� 2031 AM peak Do Something traffic volume comparison 39�Figure 6-D� 2031 PM peak Do Something traffic volume comparison 39�Figure 6-E� 2031 AM peak Do Something link speeds and delay 41�Figure 6-F� 2031 PM peak Do Something link speeds and delay 41�Figure 6-G� AM peak journey time difference with mitigation packages 45�Figure 6-H� PM peak journey time difference with mitigation packages 45�Figure 6-I� AM peak maximum delay per vehicle 47�Figure 6-J� PM peak maximum delay per vehicle 47�Figure 6-K� AM peak hour total number of vehicles using junction 48�Figure 6-L� PM peak hour total number of vehicles using junction 48�Figure 6-M� 2031 AM peak flow differences - Winchbottom Lane 49�Figure 6-N� 2031 PM peak flow differences - Winchbottom Lane 50�Figure 6-O� 2031 AM peak flow differences - Ragmans Lane 50�Figure 6-P� 2031 PM peak flow differences - Ragmans Lane 51�Figure 7-A� 2031 Land North of Heath End Rd (A) AM peak modelled flows 57�Figure 7-B� 2031 Land North of Heath End Rd (A) PM peak modelled flows 57�Figure 7-C� 2031 AM Land North of Heath End Rd (A) traffic volume

comparison 58�Figure 7-D� 2031 PM Land North of Heath End Rd (A) traffic volume

comparison 58�Figure 7-E� M40 Junction 3a slip road traffic distribution (Package A) 59�Figure 7-F� 2031 AM Land North of Heath End Rd (C) link speeds and

delay 62�Figure 7-G� 2031 PM Land North of Heath End Rd (C) link speeds and

delay 62�Figure 7-H� AM peak journey time difference with mitigation packages 64�Figure 7-I� PM peak journey time difference with mitigation packages 64� Appendix A� Glossary of Terms�Appendix B� Traffic Volumes - High Wycombe�Appendix C� Traffic Volumes Link Capacity and Delay – Wooburn Town�Appendix D� Historic Traffic Growth – High Wycombe Area�Appendix E� Handy Cross TRANSYT Analysis�Appendix F� Transport Mitigation Packages�Appendix G� Land Use Traffic Distributions�Appendix H� Link Volume Traffic Distribution – Key Schemes�Appendix I� Land North of Heath End Rd (M40 J3a) – Sensitivity Test�

Wycombe District Local Plan - High Wycombe Area - Transport Study - Final.docx 1

1 Introduction

1.1 Purpose of Report

Jacobs are framework consultants to the Transport for Buckinghamshire Alliance (TfB) between Ringway Jacobs and Buckinghamshire County Council (BCC). Under the terms of this contract, Jacobs are commissioned to undertake transport planning, modelling and assessment studies on behalf of the County Council, working in partnership with District Councils. Jacobs has been commissioned by BCC and Wycombe District Council (WDC) to undertake a transport study. The study provides an evidence base which demonstrates the possible traffic implications of potential new land use development and considers a range of associated transportation infrastructure schemes. The evidence base will support and inform the development of the new Wycombe District Local Plan (WDLP). This report is one of number of documents that form the background evidence for the new WDLP. This report contains an assessment of current and forecast traffic demand to identify the impacts of new land use development, taking into consideration findings from previous studies and relevant policy and strategy documents. Together, this information provides: • an assessment of the impact of additional housing and employment-related

land use in and around the High Wycombe urban area • a comparative assessment of the traffic and transportation implications of

locating new land use development in particular areas • the role of transport network improvements and new strategic transport

infrastructure provision in mitigating the impact of new land use development

From this assessment, an understanding of the traffic implications of new land use and associated highway infrastructure development in the High Wycombe area is established. 1.2 Background

In March 2012 the National Planning Policy Framework (NPPF) was published, consolidating policy statements, circulars and guidance documents into a single concise framework. The NPPF outlines the Government's economic, environmental and social planning priorities for England assisting the production of robust local and neighbourhood plans and development management decisions. Local planning authorities are required to prepare plans that accommodate new development; meeting objectively assessed local needs and priorities. WDC is developing a new Local Plan for the District. Once adopted, the Plan (WDLP) will replace the adopted Core Strategy (2008) as well as the saved policies from the existing Local Plan (2004). WDLP will sit alongside the Delivery and Site Allocations (DSA) Plan for Town Centres and Managing Development document. WDC state that the new WDLP will: • set housing targets for the district and address strategic housing issues

including housing and mixed use allocations


• include policies and proposals for the protection and provision of employment land

• include site specific proposals for local communities • set detailed policies to manage development The overall objective of this study is to provide a series of assessments relating to potential land use development and possible associated transportation infrastructure requirements in Wycombe District. The study will create an evidence base that assists and supports the development of the new WDLP. The study area for this assessment is outlined in Figure 1-A which includes the urban area of High Wycombe and an area in the vicinity of Wooburn Town.

Figure 1-A Study area

1.3 Overview of Modelling Assessment

The High Wycombe Highway Assignment Model (HWHAM) is a strategic highway model with the capability to model both existing and future traffic scenarios, land use scenarios and road network infrastructure improvement options. The model is validated to a 2013 base year and reflects typical weekday morning and evening peak traffic conditions. Further details of the model are presented in the report ‘High Wycombe Highway Assignment Model - Local Model Validation Report, January 2014’. A forecast 2031 Do Minimum scenario has been developed to inform this assessment. This forecast scenario includes committed developments and those allocated in the adopted Local Development Framework, and background growth obtained from TEMPRO. Further details can be found in the ‘High Wycombe Highway Assignment Model - Traffic Forecasting and Assumptions Report, January

Contains Ordnance Survey data © Crown copyright and database right 2014

N

Wooburn Town

A4094

A40

A40

M40

A404(M)

A4010

A4094

A404

A404

A4128


2014’. The 2031 Do Minimum scenario establishes a forecast of traffic conditions within the study area, against which various new land use and infrastructure scenarios can be assessed comparatively. A stand-alone assessment tool has been developed for Wooburn Town as this area is outside the extent of HWHAM. This assessment consists of a spreadsheet-based network model supplemented by detailed junction assessment models. Year 2031 Do Minimum scenarios have also been established and form the basis of the transport study for this area. The transport modelling and assessment tools consider typical peak hour traffic conditions as per industry-standard model development and transport assessment guidance. The data derived from the model reflects the average conditions across each peak hour but does not reflect conditions that may occur during exceptional events. A series of possible land use and infrastructure scenarios for High Wycombe, Wooburn Town and other areas have been identified in consultation with WDC and BCC. An additional assessment of a separate employment-led land use development at Land North of Heath End Road is undertaken using HWHAM. This assessment considers the impact of a number of associated strategic transport packages including a potential new motorway junction referred to as ‘M40 Junction 3a’. Further information on the land use and infrastructure scenarios is presented later in this document.

It is important to note that the locations assessed for potential new land use development and transport infrastructure in sections 5 to 7 of this study reflect theoretical areas of change. These scenarios have been established to assist in the development of the Wycombe District Local Plan and are not related to any specific planning applications. A staged approach has been adopted to reduce the number of assessment scenarios to a practical level: • Stage 1 – Cumulative assessment of all land use development areas in High

Wycombe and Wooburn Town. • Stage 2 – Assessment of the impacts of three different transport packages

for key land use sites (explained further in section 5). • Stage 3 – Additional assessment of a separate employment-led land use

development scenario and consideration of three associated strategic transport packages

These scenarios are used to identify, in traffic performance terms, the impact of the sites and the impacts of a range of transport infrastructure measures. 1.4 Structure of Report

The structure of this transport study report is as follows: • Section 1 – Introduction - Outlines the purpose and background of the report • Section 2 – Policy and Document Review - Reviews relevant policy and

strategy documents to ensure consistency with Buckinghamshire’s existing policies and programmes


• Section 3 – Baseline Review - Describes existing transportation conditions to provide a clear understanding of existing traffic supply and demand in the study area

• Section 4 – High Wycombe Area in 2031 - Presents the forecast traffic conditions under a ‘Do Minimum’ scenario and describes a number of key public transport and non-motorised user schemes

• Section 5 – Land Use and Infrastructure Scenarios - Outlines the methodology for the traffic forecasting and modelling process and provides an overview of the theoretical land use and infrastructure scenarios

• Section 6 – Traffic Assessment and Appraisal - Presents the results from the traffic forecasting and modelling process and describes the impacts of the land use and transport infrastructure scenarios

• Section 7 – Land North of Heath End Road (M40 Junction 3a) – Describes the traffic impacts of a separate set of land use and transport infrastructure packages

• Section 8 – Summary and Conclusions - Presents a summary and the conclusions of the report


2 Policy and Document Review

2.1 Introduction

In assessing the impact of the land use development and transportation infrastructure scenarios within the study area, it is important to examine and review existing planning policies and objectives to ensure that any schemes assessed and conclusions drawn from this study are consistent with policy. This section outlines the key strategies and policies relating to planning and transport as articulated at the National, Regional and Local level. Policy has been and continues to be in a state of change and development; therefore the information presented in this report is accurate at the time of writing but may change during the course of WDLP production. 2.2 Policy Review

2.2.1 National Policy

National Planning Policy Framework Under the Coalition Government, planning policy has changed significantly. Outlined within the Local Growth White Paper1, the focus for planning and future development is one that helps to deliver strong, sustainable and balanced growth, whilst also being tailored to local aspirations and requirements. In March 2012, the Department for Communities and Local Government published the ‘National Planning Policy Framework (NPPF)2, which sets out the Government’s economic, environmental and social planning policies. The NPPF aims to reform the planning system and is underpinned by a presumption in favour of sustainable development which for plan making means that ‘local planning authorities should positively seek opportunities to meet the development needs of their area’. There is a focus on planning for prosperity, people and places, promoting increased levels of development and supporting infrastructure, whilst also protecting and enhancing the natural and historic environment. It is designed, however, to be interpreted and implemented locally; and delegates responsibility for achieving this vision to local planning authorities. Localism Act The Coalition Government’s Localism Act3 provides the legislative foundation for this change. The Act decentralises power, giving local government new freedom and flexibilities; provides new rights and powers for communities and individuals; reforms the planning system; and enables decisions to be taken locally. The Coalition Government’s vision for transport is also one that encourages growth, but is greener, safer and improves the quality of life in our communities. The Government’s transport priorities and key actions in order to deliver this national

1 Local growth: realising every place’s potential http://www.bis.gov.uk/assets/biscore/economic-development/docs/l/cm7961-local-growth-white-paper.pdf 2 National Planning Policy Framework http://www.communities.gov.uk/documents/planningandbuilding/pdf/2116950.pdf 3 Decentralisation and the Localism Bill: an essential guide http://www.communities.gov.uk/documents/localgovernment/pdf/1793908.pdf


vision are set out within the Department for Transport’s (DfT) Business Plan4, which is updated annually. There is a focus on improving road safety, reducing congestion and pollution and making changes at a local level. The ‘Local Transport White Paper – Creating Growth, Cutting Carbon: Making Sustainable Local Transport Happen’5 published in January 2011 sets out the Coalition Government’s vision for a sustainable local transport system that supports the economy and reduces carbon emissions. The focus is on enabling local authorities to meet local transport needs, through a simplified approach to funding and increased power and flexibility. It emphasises that effective sustainable local transport is achieved through solutions developed for the places they serve, tailored for the specific needs and behaviour patterns of individual communities. The Strategic Road Network and the Delivery of Sustainable Development The DfT Circular 02/2013 ‘The Strategic Road Network and the Delivery of Sustainable Development’6 (September 2013) sets out that the effective and efficient operation of the Strategic Road Network (SRN) will contribute to creating ‘the conditions that support the realisation of the aspirations of business and communities’ and is an important factor in the delivery of national economic growth. The document sets out how the Highways Agency (HA) will engage in the development of Local Plans to reduce the potential for adverse impact upon the SRN. The Local Plan preparation process provides an opportunity to influence patterns of development to minimise trip generation and journey lengths, and to maximise the use of sustainable modes of transport. A key objective for the HA is to ensure that the fulfilment of the primary purpose of the SRN is not compromised. The Circular emphasises the role of sustainable transport solutions in Local Plans and the importance of travel planning and demand management measures, for example. Transport solutions would be aligned to ‘existing and proposed patterns of development in a manner that will support sustainable transport choice and retain capacity within the transport network so as to provide for further development in future Plan periods’. Route Based Strategies The Highways Agency is developing Route-Based Strategies7 (RBS) which will inform a Roads Investment Strategy for the strategic road network. A key objective of the RBS is to help support and sustain economic development. As part of this process, the HA are engaging with Local Authorities in order to take account of local priorities for growth as well as balancing national and local needs on the network. 2.2.2 Regional / Local Policy and Guidance

The Buckinghamshire Thames Valley Local Enterprise Partnership Included in the Localism Act is the power to abolish Regional Spatial Strategies and with that the South East Plan, which previously set out the region’s targets for housing, economy, transport and environmental challenges. Local Enterprise Partnerships (LEPs) have taken on Regional Development Agencies’ role in this 4 Business Plan 2013-15 http://transparency.number10.gov.uk/business-plan/11 5 Creating Growth, Cutting Carbon: Making Sustainable Local Transport Happen http://www.official-documents.gov.uk/document/cm79/7996/7996.pdf 6 The Strategic Road Network and the Delivery of Sustainable Development https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/237412/dft-circular-strategic-road.pdf 7 Route-Based Strategies http://www.highways.gov.uk/our-road-network/managing-our-roads/improving-our-network/route-based-strategies/


process, with Wycombe District forming part of the Buckinghamshire Thames Valley LEP (BTVLEP). The vision of the BTVLEP is ‘to create a vibrant, balanced, competitive Buckinghamshire economy’ through providing the ‘conditions that support business to invest, grow, and thrive’8. A number of key objectives are identified for the period 2012-2031 in order to achieve this vision. These include a focus on bringing forward the necessary business-critical infrastructure and ensuring major transport infrastructure is fit for its economic purpose. In the High Wycombe area, BTVLEP is continuing to promote key strategic employment sites served by the inter-urban A4010 and A40, including the town centre. Buckinghamshire’s Local Transport Plan 2011-2016 Buckinghamshire’s Local Transport Plan 2011-20169 was adopted in April 2011. It is the third Local Transport Plan (LTP3) for the county, setting out policies, strategies and priorities to address transport related issues and challenges across the five years to March 2016. The LTP3 is focused on addressing the five themes of the Sustainable Communities Strategy10 (SCS), which sets the long-term plan for the county up to 2026:

• delivering a thriving economy • sustainable environment • safer communities • health and wellbeing • cohesive and strong communities In supporting the delivery of a thriving economy, LTP3 recognises that encouraging employment growth in the county and delivering sustainable housing growth are two key challenges. Within the District, High Wycombe is identified as an area likely to experience significant housing and employment growth; however, other transport related land use planning issues stemming from this are outlined as follows: • High Wycombe town centre proposals • air quality • in-commuting pressure • rural accessibility • Marlow and Princes Risborough vitality • development pressure on the high quality environment Local Area Strategy - High Wycombe and Chepping Wye Valley (2011-16) The County LTP3 Strategy is supported by the Local Area Strategy11 for the High Wycombe and Chepping Wye Valley, covering the same period. The Local Area Strategy seeks to deliver a strong economic centre for High Wycombe, and sets out an Urban Strategy to: 8 Buckinghamshire Local Enterprise Thames Valley Partnership 2012 – 2031 - Plan for Sustainable Economic Growth in the Entrepreneurial Heart of Britain http://buckstvlep.co.uk/uploads/downloads/SEQ129_BBF_BusinessPlan_0912_LOW-1.pdf 9 Buckinghamshire’s Local Transport Plan 2011-2016 http://www.tfbucks.co.uk/documents/ltp/LTP3.pdf 10 Sustainable Community Strategy for Buckinghamshire 2009–2026 http://www.buckinghamshirepartnership.gov.uk/assets/content/Partnerships/BSP/docs/bsp_scs_visual_county.pdf 11 Local Transport Plan Local Area Strategies http://www.tfbucks.co.uk/documents/ltp/LTP3_Local_area_strategies.pdf


• support delivery of the town centre vision and masterplan • accommodate new housing and employment growth • tackle congestion • increase levels of active travel • address poor air quality in the town centre

The approach contains a mix of schemes and initiatives involving the transfer of journeys to sustainable modes, re-routing cross-town journeys to distributor routes, intercepting and transferring car journeys to park and ride, and managing the network to deliver better journey times and reduce air quality issues. Southern Quadrant Transport Strategy (SQTS) The SQTS12 was adopted in November 2012 by BCC. SQTS sets a ten year vision for transport in the southern area of High Wycombe by establishing priorities and schemes that will deliver positive benefits, supporting WDC land use planning. The strategy sets out BCC’s vision for dealing with increasing travel demands forecast for the area, associated with land use development sites including Handy Cross Hub and RAF Daws Hill. Wycombe Local Development Framework WDC has an emerging Local Development Framework comprising the following: • adopted Core Strategy 200813 • emerging New Wycombe District Local Plan14 • Delivery and Site Allocations (DSA) Plan, June 201215 • Wycombe Infrastructure Delivery Plan (IDP), May 201216 • High Wycombe Town Centre Masterplan (TCMP) as part of the DSA17

The adopted Core Strategy sets out the vision and spatial strategy for Wycombe District up to 2026. The focus is on transforming previously developed land in High Wycombe to deliver an urban renaissance, with the town acting as a regional hub and principal focus for development. The strategy contains policies for a number of “Key Areas of Change” including Hughenden district and Desborough Avenue. Policy CS8 describes ‘Reserve Locations for Future Development’ which are subject to assessment in this report. The reserve locations (not listed in priority order) are: • Abbey Barn North, High Wycombe • Abbey Barn South, High Wycombe • Gomm Valley, High Wycombe • Slate Meadow, Wooburn Town (Bourne End) • Terriers Farm, High Wycombe

12 Southern Quadrant Transport Strategy http://www.transportforbucks.net/Strategy/LTP3/Local-Area-Strategies.aspx 13 Adopted Core Strategy http://www.wycombe.gov.uk/council-services/planning-and-buildings/planning-policy/wycombe-development-framework/adopted-core-strategy.aspx 14 New Local Plan http://www.wycombe.gov.uk/council-services/planning-and-buildings/planning-policy/new-local-plan.aspx 15 Delivery and Site Allocations Plan http://www.wycombe.gov.uk/council-services/planning-and-buildings/planning-policy/delivery-and-site-allocations-plan-examination.aspx 16 Wycombe Infrastructure Delivery Plan http://www.wycombe.gov.uk/council-services/planning-and-buildings/planning-policy/community-infrastructure-levy/examination.aspx 17 High Wycombe Town Centre Masterplan http://www.wycombe.gov.uk/council-services/planning-and-buildings/planning-policy/wycombe-development-framework/high-wycombe-town-centre-technical-studies.aspx


The emerging WDLP will replace the adopted Core Strategy as well as the saved policies from the existing Local Plan (2004). The new WDLP will also address economic issues and identify land for business development. The need for a new WDLP is triggered by the abolition of the South East Plan housing targets through the Localism Bill, which informed the adopted WDC Core Strategy. The new WDLP will set housing targets for the District and address strategic housing and economic issues. It will also set out the detailed policies to manage development. The DSA translates the high level policies of the Core Strategy into more detailed policies and site specific allocations for town centres. It also identifies and plans the delivery of the infrastructure needed to support this development. The DSA includes ‘District-wide Development Management Policies’ as per policy DM2 which aims to tackle the transport related challenges created by major developments and adds further detail to supplement Core Strategy policy CS20. This policy states ‘all developments that require the submission of a Transport Assessment, in line with Appendix B of the DfT Guidance on Transport Assessment (March 2007), or any replacement to this guidance, or as required by the Highway Authority, should provide’ a range of transport improvements relating to: • public transport • walking and cycling • travel plans • car clubs • car sharing The design of development should allow for bus penetration through the sites and priority bus routing, traffic management that ensures queues are managed in a way that mitigates their impact on the primary highway network, and layout and design that realises high quality places that are not dominated by the needs of vehicular traffic. WDC will as far as practicable seek to ensure that new development has a neutral effect on the highway network. Community Infrastructure Levy (CIL) The Wycombe CIL was formally introduced in 2012. CIL is a local tariff that enables Local Authorities to set a charge for most types of new land use development. The money is available to fund a wide range of local and strategic infrastructure that is required as result of development such as transport schemes, green infrastructure, schools and community facilities. The DSA sets out that ‘it is vitally important that new development provides appropriate measures to encourage sustainable transport behaviour as well as, through the CIL, contributions towards the wider strategy as produced by the County Council so as to offset the wider traffic impacts and meet the travel needs of users of the development’.


3 Baseline Review

3.1 Introduction

This section reviews the existing population, land use and transportation infrastructure supply and demand. Travel conditions within the study area are described using a variety of existing data sources including traffic volume, journey patterns, and congestion and delay. Provision for public transport and non-motorised users is described with data related to travel volumes where available.

3.2 Population Characteristics

At the time of the 2011 Census, the study area (see Figure 1-A) had a total population of 100,316. Of these, 98,470 resided in 38,639 households. The remainder were resident in communal establishments e.g. care homes, boarding schools. Figure 3-A shows the percentage of households owning various numbers of vehicles within the study area. Overall, 83% of households have access to at least one vehicle. This is slightly lower than the overall figure for Wycombe District which is 86%, but higher than the 74% average for England. The main means of travel to work for working age (16 – 74) residents who reside in the study area is shown in Figure 3-B.

Figure 3-A 2011 Census household vehicle ownership

Figure 3-B 2011 Census main method of travel to work

Source: ONS

Source: ONS

Source: ONS


A total of 45% of working age residents drive a car or van as their main method of travel to work, with 7% using public transport. The corresponding percentage for those driving a car or van for this purpose in England is 37%, with 11% using public transport. The statistics for Wycombe District are similar to those for the study area. Overall, the study area is characterised by relatively high car ownership and a relatively high proportion of travel to work by car or van. 3.3 Highway Network

(a) Description

High Wycombe is located in the south of Buckinghamshire, situated approximately 29 miles north-west of London. The highway network is shown in Figure 3-C. High Wycombe lies to the north of the M40, with access to the strategic road network via Junction 4 at Handy Cross to the south of the town centre and Junction 3 to the east at Loudwater. The A4010 in the west of the town provides a strategic route to mid and north Buckinghamshire; connecting with the Handy Cross junction to provide a north-south route for traffic which avoids the town centre. Wooburn Town is situated in the vicinity of Bourne End to the south-west of High Wycombe and to the south of the M40 Junction 3. There are three main routes into this area including the A4094 from the north, the A4094 south from Maidenhead, and the A4155 Marlow Road from the west.

Figure 3-C Local highway network

The primary destinations around High Wycombe include Amersham, Beaconsfield, Maidenhead and the Thames Valley, Oxford and Aylesbury. Traffic travelling between these destinations is served by the M40, A404, A4010 and A355. Another major longer distance route through High Wycombe town centre is the route from Amersham and surrounding areas to Maidenhead and the Thames Valley in the south.

N



High Wycombe town centre is served by five key radial routes which meet at either end of the elevated Abbey Way flyover in the town centre. The A40 runs east – west through the town with dual carriageway sections from Oxford Road through to Abbey Way at Easton Street, including the flyover. The A4128 Hughenden Road provides a route to / from the north and joins the A40 at the Oxford Road roundabout. The A404 runs north-south through the town, and includes Amersham Hill to the north and the dual carriageway Marlow Hill to the south. Both routes have steep gradients with High Wycombe town centre situated in a valley bottom. (b) Traffic volumes

The HWHAM 2013 base year traffic model reflects current traffic conditions. The model has been used to establish the main traffic movements in and around High Wycombe. Details of the base model development are provided in the Local Model Validation Report (LMVR)18. Figure 3-D and Figure 3-E show the 2013 base modelled traffic volumes for the AM and PM peaks respectively with volume indicated by bandwidth and shading. Annotated figures are shown in Appendix B. Apart from the M40, the highest traffic volumes are found on the Handy Cross, Abbey Way and Marlow Hill road links and gyratory systems, reflecting the higher road standards and number of lanes at these locations. There are also road links with high flows in excess of 1,000 vehicles per hour on the A40 West Wycombe Road, A4128 Hughenden Road, A404 Amersham Road and A40 London Road. The A4094 in Wooburn Town accommodates 700 – 900 vehicles in the AM peak and 600 – 700 in the PM peak (see Appendix C).

Figure 3-D 2013 AM peak modelled flows

18 High Wycombe Highway Assignment Model, Local Model Validation Report, January 2014

N



Figure 3-E 2013 PM peak modelled flows

(c) Journey Patterns

Analysis19 of the origins and destinations of trips based on the HWHAM is illustrated for the AM peak in Figure 3-F. 33% of trips have both an origin and destination within the study area (internal trips). A further 46% of trips have either an origin or a destination in the study area, over two-thirds of which come from or are going to locations elsewhere in Buckinghamshire. The remaining 21% are trips passing through the study area, shown shaded grey in Figure 3-F.

Figure 3-F 2013 AM base model trip distribution

19 This analysis excludes M40 through trips which do not enter the High Wycombe urban area.

N



The pattern in the PM peak is very similar to the AM peak, with 31% internal trips, 46% with one end of the trip within the study area and 23% through trips. Figure 3-G illustrates the pattern of external trips passing through the High Wycombe urban area. The AM and PM peaks show a similar overall pattern in terms of routes and therefore only the PM peak pattern is presented. Trips between the M40 and the A404(T)/Wycombe Road (2,562 trips in the AM peak and 2,680 in the PM peak) passing through the Handy Cross junction are not illustrated as the purpose of this figure is to present through-trips within the urban area. A feature of both peaks is the low level of through traffic on the A40 West Wycombe Road east of Chapel Lane, and the A40 London Road, primarily a result of the presence of the M40 to the south which provides for strategic east-west movement.

Figure 3-G 2013 PM peak through trips

In the AM peak the major through movements are in both directions between the A40 West Wycombe Road and the M40 (East) and A404(T) and southbound on the A4128 Hughenden Road to onward destinations via the M40 (East) and the A404(T). There is also a notable through trip movement southbound on Holmer Green Road to the B474 towards Beaconsfield. In the PM peak there is a similar pattern of movement although with a primarily northbound orientation, including the movements from M40(East) and A404(T) to A40 West Wycombe Road and A4128 Hughenden Road.

N



(d) Journey Time and Delay

The modelled journey times were calculated for a selection of routes into, through and out of the town based on information from the HWHAM transport model. The routes are illustrated in Figure 3-H.

Figure 3-H Journey time routes

The resulting modelled average journey times and journey speeds for the AM and PM peaks are presented in Table 3-A.

AM Peak PM Peak

No. Description

Time mm:ss

Speed mph

Time mm:ss

Speed mph

1 Handy Cross to West Wycombe 09:12 19.6 11:00 16.4

2 West Wycombe to Handy Cross 12:14 14.8 10:24 17.4

3 Handy Cross to Amersham Road 12:28 17.8 13:11 16.8

4 Amersham Road to Handy Cross 16:26 14.2 13:45 16.9

5 London Road inbound 10:29 14.0 10:56 13.5

6 London Road outbound 13:47 10.7 10:57 13.4

7 West Wycombe to Town 09:56 14.1 08:50 15.9

8 Town to West Wycombe 08:35 16.3 10:11 13.8

9 Hughenden Valley Road to Town 09:17 11.5 04:46 22.4

10 Town to Hughenden Valley Road 05:13 20.7 07:05 15.3

Table 3-A 2013 AM and PM peak modelled journey times

N



Figure 3-I presents the modelled link speeds and maximum delays at key junctions for the 2013 AM peak. The same information for the PM peak is shown in Figure 3-J. The link speeds are colour coded, with darker colours reflecting slower speeds and greater levels of congestion. The link speeds also reflect the impact of traffic calming measures and different speed limits. Junction delays are also shown representing the maximum delay across the peak hour with darker colours representing greater levels of delay. Congestion within the network is a result of junction capacity constraints, link capacity constraints or a combination of both. A selection of 20 key junctions is shown to illustrate junction performance.

Figure 3-I 2013 AM peak modelled link speeds and delay

The slowest journeys in the AM peak are the A40 London Road outbound and the A4128 Hughenden Road southbound. The AM peak link speed plot indicates that the most significant areas of congestion and delay are at the Rayners Avenue / Frederick Place junction and the Gomm Road junction. The lowest link speeds are on either side of the Rayners Avenue junction. The information for the A4128 Hughenden Road route indicates that the road links are the primary cause of reduced journey times along this route. The links approaching the Bellfield Road / Glenisters Road and Coates Lane / Green Hill junctions indicate low link speeds. A number of other road links are shown to experience slow speeds in the AM peak. The eastbound direction of the A40 West Wycombe Road on the approach to the Chapel Lane junction typically experiences significant congestion associated with longer distance through trips and local traffic. On the A4010 route, slow speeds are also shown on the approach to the Cressex Road / John Hall Way junction associated with a complex land use arrangement and a mix of conflicting movements.

N



Slow link speeds are also shown in both directions on Daws Hill Lane associated with congestion caused by school drop-off traffic and traffic calming measures, congestion on Marlow Hill southbound and at the Marlow Hill gyratory, and traffic calming measures which limit the travel speeds along this route through-out the day. In Wooburn Town, the Cores End Road link to the west of the roundabout with Kiln Lane is approaching link capacity and typical link speeds are constrained through this section of road network. A number of key junctions are shown to experience relatively high levels of delay during the AM peak. The junctions most under pressure in the AM peak are the A40 / Pastures, M40 Handy Cross, A40 / Rayners Avenue, A40 / Gomm Road, A40 / Chapel Lane and the A404 Abbey Way gyratory. In Wooburn Town, the Cores End Road / Kiln Lane / Brookbank Road roundabout is approaching capacity and delays are experienced during this peak (see Appendix C). Figure 3-J presents the link speed and average maximum junction delay information for the PM peak.

Figure 3-J 2013 PM peak modelled link speeds and delay

The slowest journeys in the PM peak are the A40 London Road in both directions and the A40 westbound towards West Wycombe. The PM peak link speed plot indicates that the most significant areas of congestion and delay on the A40 London Road are at the Rayners Avenue / Frederick Place junction and the Abbey Barn Lane junction. The lowest link speeds are on either side of Rayners Avenue. For the A40 West Wycombe Road, the link to the west of Chapel Lane is shown to experience reduced speeds and the junction of A40 / Chapel Lane and A40 / Pastures are both shown to experience relatively high delays.

N



A number of other links are shown to experience slow speeds in the PM peak including the A4128 Hughenden Road northbound and Daws Hill Lane, primarily as a result of traffic calming measures during this peak period. The road links in Wooburn Town operate within capacity during the PM peak. The pattern of junction delay in the PM peak is similar in comparison to the AM peak. The A40 Marlow Hill gyratory and A40 / Abbey Barn Lane are shown to experience greater levels of delay in the PM peak. In Wooburn Town, the level of junction delay in the PM peak is less than the AM peak, and junctions typically operate within capacity (see Appendix C). Local experience also suggests occasional severe events associated with incidents on the M40 for example can affect journey times and delays within the study area. (e) Road Safety

Analysis of collision data provided by BCC for the three-year period January 2009 to December 2011 highlights a number of collision clusters at junctions in and around the High Wycombe area. These are listed in Table 3-B.

Junction No. of collisions

A40/Desborough Avenue/The Pastures 12

Oxford Road/Bellfield Road/Brook Street 8

Desborough Road/Westbourne Street 7

West Wycombe Road/Victoria Street 6

Desborough Park Road/Abercromby Avenue 6

Desborough Avenue/Desborough Road 5

Desborough Road/Bridge Street 4

Desborough Road/West End Street 3

A40/Chapel Lane 4

A4010/Cressex Road 9

Crendon Street/Castle Street 8

Table 3-B Collision clusters at junctions in High Wycombe 2009-2011

The junctions with the highest number of collisions are the A40 / Pastures junction and the A4010 / Cressex Road junction. The majority of these clusters are concentrated in the western quadrant of the town including the A40 West Wycombe Road and Desborough Road. BCC has a rolling programme of safety-focused highway improvements and behaviour change initiatives. However, the primary cause for the majority of the collisions relates to driver behaviour factors rather than highway geometry and layout. (f) Air Quality

Wycombe District has a declared Air Quality Management Area (AQMA) covering the M40 south of High Wycombe and has proposed an AQMA in High Wycombe urban area covering major routes and the town centre (shown in Figure 3-K).


According to the Wycombe 2013 Progress Report20 ‘exceedences of the annual mean nitrogen dioxide objective continue to be measured within the proposed High Wycombe AQMA, reinforcing the need for declaration’. WDC intend to review and update the current Action Plan following the expansion of the AQMAs’.

Figure 3-K Outline of proposed High Wycombe AQMA

3.4 Public Transport

(a) Rail

The Chiltern Railways line passes through High Wycombe, with a station on the eastern side of the town centre adjacent to the A404 Amersham Road. This line provides links from High Wycombe to London (Marylebone) in the south east and Bicester in the north, with a connection at Princes Risborough to Aylesbury. Typical service patterns include eight trains per hour, including five to London (Marylebone) with journey times of 30 minutes for some services; and additional services during the peak periods. High Wycombe is the busiest station in Buckinghamshire. Entries and exits at the station have fluctuated in recent years, however, between 2010/11 and 2011/12 there was an increase of 6.2% in passenger usage. Annual rail passenger usage for the station is summarised in Figure 3-L. Bourne End railway station is situated around a mile from Wooburn Town along the A4094 Cores End Road and offers services to the south into Maidenhead for connecting journeys to the wider Thames Valley, London and to the west towards Marlow.

20 2013 Air Quality Progress Report: Wycombe District Council (May 2013) http://www.wycombe.gov.uk/council-services/environment/pollution/air-pollution/air-quality-management.aspx

Contains Ordnance Survey data © Crown copyright and database

N


Figure 3-L Summary of total entries and exits for High Wycombe station

(b) Bus

High Wycombe forms a hub for the Buckinghamshire bus network; it is served by over 20 different routes operating 7 days a week and has one of two major bus stations within the County. The High Wycombe bus station is situated on the western side of the town centre adjacent to Bridge Street and was opened as part of the Eden Centre development. The bus station is a well-used, pleasant and modern transport interchange with electronic display screens and seating areas. Although it has only been open for a few years, the bus station is understood to experience capacity issues which can lead to service delays and journey time reliability issues. High Wycombe is served by an extensive bus network. Regional services operate along the key radial routes between High Wycombe and neighbouring towns, with typical frequencies of every 30-60 minutes daily. High Wycombe Park and Ride service PR1 also offers a route to High Wycombe town centre from Junction 4 of the M40 at Cressex Island. Within High Wycombe, the Rainbow Routes network provides high frequency, local services throughout the town. It comprises a series of colour branded bus services developed through quality partnerships, most of which operate every 15-20 minutes as outlined in Figure 3-M. The principal services for the Bourne End area including Wooburn Town are Rainbow Routes 35 and 36 which provide a frequent service along the A4094.

��

��

��

��

��

��

��

��

��

�

��Source: ORR


Figure 3-M High Wycombe Local Bus Routes

The bus services in High Wycombe provide an opportunity to access a number of neighbouring settlements by sustainable means. However, for longer distance journeys services are less frequent. There is a target within the LTP3 Implementation Plan for 85% of all bus services across the county to run on time and to increase bus patronage. 3.5 Non-motorised Users

(a) Cycling

Cycling makes up less than 1% of journey to work trips within the High Wycombe area (Census 2011). The use of cycling as a mode of travel is limited within the area in part by significant topographical constraints, in particular in a north-south direction. However, there are a number of areas within the town that offer potential for greater volumes of cycle trips. These include journeys along the Wye Valley bottom; journeys within the Cressex and Handy Cross area to the south of the town; and from Terriers and Hazlemere to the north. The 7 kilometre signed High Wycombe East-West Cycle Route links Station Road, Loudwater to the east with Chapel Lane at the western end of the town. It passes close to the town centre, where there is a number of cycle parking facilities. The cycling parking facilities introduced at High Wycombe station in recent years are reportedly well used, suggested that there is further potential for expansion in the number of cycling trips within the area.


(b) Walking

According to the 2011 Census, 7% of people travel on foot as part of their journey to work within the High Wycombe area. The attractiveness of walking as a transport mode is similarly constrained by topographical features, particularly for north-south journeys within High Wycombe. The Walk Wycombe project launched in May 2010 is designed to ‘embed walking in the daily routine for those who live and work in High Wycombe’. BCC has focused Walk Wycombe marketing campaigns on local schools in order to increase the mode shares of non-motorised modes. Online information includes detailed directions for walking journeys in High Wycombe, available on the Walkit21 website.

3.6 Summary

This section has set out evidence which describes the current supply and demand for transport within the High Wycombe area. The evidence is based on observed data and validated transport modelling tools, and reflects the current typical strategic transport volumes, journey patterns, journey time and delay. The provision for and use of public transport and non-motorised users is described to provide context to later sections of this report. Many of the strategic corridors typically experience peak time congestion with reduced link speeds and increased vehicular delays despite reductions in traffic volume. A number of local routes experience reduced speeds associated with link or junction congestion with occasional severe events associated with incidents on the M40 for example. However, congestion is typically limited to a proportion of the peak hour only and link speeds quickly return to free flow operation. This baseline review has set the context for the assessment of forecast scenarios including land use and transport mitigation packages. As such, this evidence is a basis for assessing the implications for the High Wycombe area of increasing volumes of traffic which may result from new land use development options.

21 The urban walking route planner http://walkit.com


4 High Wycombe Area in 2031

4.1 Introduction

This section provides an assessment of the forecast transport conditions in the High Wycombe area in 2031 without the new land use development options considered in WDLP. The data in this section is derived from the 2031 Do Minimum forecast of the HWHAM and the Wooburn Town network model.

The 2031 Do Minimum forecast includes traffic growth associated with all ‘committed’ development sites (see section 4.2). The forecast also includes highway schemes associated with those developments, infrastructure policies related to the DSA and infrastructure funded through DfT funding bids. Some of the schemes are part of the wider HW TCMP which is part of the DSA policy framework for the future development of the town centre. A complete list of schemes included in the Do Minimum forecast network can be found in the report ‘High Wycombe Highway Assignment Model - Traffic Forecasting and Assumptions, January 2014’.

4.2 Land Use

The Do Minimum scenario includes all ‘committed’ forecast land uses. This includes:

• sites with planning permission • sites that do not yet have planning permission, but are approved in principle,

subject to the completion of a Section 106 or planning obligation agreement • sites consistent with the Core Strategy or DSA expected to come forward

within the period defined within the current plans (to 2026)

The total provision from these developments is for around 3,000 dwellings and an employment gross floor area of 126,000m2. It is assumed that all of this development will be completed by 2031. In addition to the sites explicitly identified as ‘committed’ land use there are a number of smaller development sites, and sites outside of the study area. The highway trip growth due to these additional developments is modelled using TEMPRO background growth. The overall level of growth forecast in the 2031 Do Minimum scenario is consistent with TEMPRO growth rates. For the Wooburn Town network model, forecast growth rates including income and fuel price adjustment factors were applied directly to base year traffic volumes. 4.3 Highway Network

(a) Traffic Volume

Figure 4-A to 4-D present the forecast traffic volumes in the 2031 AM and PM peak hours and the forecast change in traffic volumes from 2013 to 2031. Appendix B presents the traffic forecast volumes in more detail. The TEMPRO data suggests significant growth in traffic volumes by 2031. It is noteworthy that expected growth in the volume of traffic has not materialised on the local road network in recent years. Observed DfT count data shows marked reductions in traffic volume within the High Wycombe area since the year 2000 (see Appendix D) with an overall reduction in traffic of 14%. This suggests these growth forecasts may over-estimate eventual conditions in terms of traffic volumes.


Figure 4-A 2031 Do Minimum AM Peak modelled flows

Figure 4-B 2031 Do Minimum PM Peak modelled flows

N


N



Figure 4-C Change in AM peak traffic volumes between 2013 and 2031

Figure 4-D Change in PM peak traffic volumes between 2013 and 2031

N


N



The largest traffic volume increases occur on the M40, in both directions. This is a result of a proportional increase in traffic volumes consistent with the National Road Traffic Forecast (NRTF) growth rates for strategic highways of 13.5% for cars and 37.8% and 8.8% for LGVs and HGVs respectively. In terms of overall traffic growth for High Wycombe, there is forecast to be an increase of 20.3% in the AM peak and 20.5% in the PM peak associated with:

• new land use development generating new travel demand • changes in fuel price and income affecting travel choices • demographic factors including population age profiles which affect timing and

purpose of travel

Wooburn Town is forecast to experience a similar overall level of traffic growth with 19.0% and 19.1% in the AM and PM peaks respectively. Within High Wycombe, there are notable traffic volume changes including both increases and decreases on links around the town centre and Abbey Way. These traffic volume changes arise as a result of the road network re-configuration contained within the DSA HW TCMP policies. These changes include the provision of an alternative cross-town route via Desborough Road and major amendments to the A40 Abbey Way flyover and adjacent junctions. The principal outcome of these changes is for traffic to reroute from the Abbey Way flyover onto the alternative cross town route via Desborough Road and through the Priory Road area. Traffic redistributes as part of the changes to the eastern town centre road network, with traffic reductions on Easton Street and A40 Abbey Way as a result of the conversion of Queen Victoria Road to two way operation. Traffic volumes also change markedly following the introduction of the Dovecot area gyratory system in both peak periods. The traffic volume on a number of longer distance routes is forecast to increase. These include the A4010 north – south route via A40 West Wycombe Road to Handy Cross and the route via Holmer Green Road and B474 Penn Road to the north-east of High Wycombe. A number of local urban routes are also forecast to accommodate an increase in traffic volumes as a result of local new land use development. These include Desborough Road and roads within the southern quadrant area including Marlow Hill, Daws Hill Lane, Holmers Farm Way and Clay Lane. Other routes across the urban area of High Wycombe experience some increase in traffic volume as a result of the overall growth forecast for the area. (b) Journey Patterns

The strategic journey patterns within the High Wycombe area have not altered markedly, however a local shift in traffic has occurred within the town centre as a result of the implementation of the HW TCMP. This scheme has resulted in a modest shift of north-south traffic distribution in particular between A4128 Hughenden Road and Handy Cross, with increasing volumes of traffic utilising Desborough Road as a primary north-south corridor. (c) Journey Time and Delay

As traffic volumes increase by 2031, delays at junctions would increase and link speeds on the highway would decrease. Figure 4-E and Figure 4-F show the average link speeds and junction delays in the 2031 AM and PM peak Do Minimum forecasts respectively.


Figure 4-E 2031 Do Minimum AM peak link speeds and delay

Figure 4-F 2031 Do Minimum PM peak link speeds and delay

N


N



In general, the relative pattern of link speed and delay is similar in the forecast scenario when compared with the base 2013 scenario. However, the growth in traffic forecast to 2031 has resulted in decreases in speed and increases in delay across the network. On average, network speeds have reduced by 4.7mph to 20.5mph in the AM peak and by 5.1mph to 21.3mph in the PM peak. The number of road links with lower speeds has increased and there is a notable reduction in link speed on all strategic corridors within the town. Table 4-A presents the 2031 Do Minimum forecast corridor journey times and speeds compared with the base year.

AM Peak PM Peak

Description

time mm:ss

time diff.

speed mph

speed diff.

time mm:ss

time diff.

speed mph

speed diff.

1 Handy Cross to West Wycombe 12:26 03:14 14.5 -5.1 14:39 03:39 12.3 -4.1

4 West Wycombe to Handy Cross 16:22 04:08 11.0 -3.7 14:05 03:41 12.8 -4.5

3 Handy Cross to Amersham Road 16:52 04:24 12.9 -4.9 20:50 07:39 10.4 -6.4

4 Amersham Road to Handy Cross 19:44 03:18 10.9 -3.2 15:23 01:38 14.0 -2.9

5 London Road inbound 12:10 01:41 12.1 -1.9 12:48 01:52 11.5 -2.0

6 London Road outbound 18:36 04:49 7.9 -2.8 13:46 02:49 10.7 -2.7

7 West Wycombe to Town 14:12 04:16 9.8 -4.3 11:55 03:05 11.7 -4.2

8 Town to West Wycombe 12:01 03:26 11.6 -4.7 13:35 03:24 10.3 -3.5

9 Hughenden Valley Road to Town 12:12 02:55 8.8 -2.7 06:21 01:35 16.8 -5.5

10 Town to Hughenden Valley Road 07:05 01:52 16.2 -4.5 10:26 03:21 11.0 -4.2

Table 4-A Journey time and speed 2031 Do Minimum

In addition to those links identified in the base year assessment in section 3, additional links are now indicating particularly low speeds. These include the A4010 John Hall Way eastbound, various sections of the A40 London Road to the east of the town, and A404 Amersham Road between Kingshill Road / Totteridge Lane and Hazlemere. Many of the town centre road links show average speeds below 12 mph, however this is in part an intended consequence of the low design speeds introduced as part of the HW TCMP to help improve the town centre environment. A number of urban links including Holmer Green Road, Penn Road, Hamilton Road and Heath End Road in Flackwell Heath are forecast to experience lower speeds although the speed for the latter two links reflect the benefits of existing traffic calming. The route via Desborough Avenue which is an alternative to the A404 Marlow Hill is forecast to accommodate increased volumes of traffic and results in notably lower link speeds on this route. In Wooburn Town, the network forecast indicates the Cores End Road link to the west of the Kiln Lane roundabout would operate at capacity. In terms of junction delays, the junctions that experience the highest levels of delay in the AM peak are the A404 Marlow Hill gyratory, A40 / Rayners Avenue and M40 Handy Cross all of which show maximum delays of over 180 seconds in at least one time period. The A404 / Daws Hill Lane, A40 Gomm Road, and A40 Abbey Barn Lane junctions show delays of around 120 seconds or more. In the PM peak the A40 / Pastures junction experiences significant levels of delay. The A40 / Chapel


Lane junction improves as a result of the implementation of the committed DfT Pinch Point scheme. A detailed assessment of the M40 Handy Cross junction using TRANSYT is presented in Appendix E. The results for the Do Minimum scenario are summarised and compared with the WDLP scenario in section 6. Overall, the majority of road links in the High Wycombe area show a decrease in average speed of at least 2mph, in both the AM and PM peaks. In terms of junction delays, the majority of junctions considered in detail in the figures show an increase in delay of at least 30 seconds in 2031, compared to current conditions. (d) Air Quality

An increase in traffic volume and corresponding reduction in speeds either as a result of congestion or as an intended feature of scheme design would result in a degradation in air quality. WDC plan to update and review the current Air Quality Action Plan following expansion of current AQMA’s (as explained in section 3.3 (f)). 4.4 Public Transport

BCC works with the DfT, public transport operators and developers in order to deliver public transport improvements for Buckinghamshire. There are forward plans to upgrade existing bus stops with real time passenger information (RTPI) systems and other improvements through the Wycombe Route Improvement Plan. There are also opportunities to maximise the journey time reliability benefits that can be provided by BCC’s Urban Traffic Management Control (UTMC) systems. In the town centre, the HW TCMP will deliver a more permeable transport network for buses which will improve the journey time reliability of public transport services in the town. There are three major sub-regional public transport projects that are expected to provide significant journey time and accessibility benefits for the High Wycombe Area. The benefits of the schemes have not been taken into account in the forecast modelling assessment so it is important that the results of the transport study are considered in this wider context. Chiltern Railways Evergreen 3 This project is the latest set of planned service improvements to be implemented as part of Chiltern Railways franchise agreement. This follows earlier Evergreen 1 and 2 improvements which included track doubling between Bicester and Banbury, measures to improve line speed and signalling, and additional platforms at London Marylebone. Chiltern Railways envisages operating two London – Oxford trains each hour in each direction throughout the day, with most trains stopping at High Wycombe. The journey time for High Wycombe to Oxford will be 38 minutes compared to a current journey time by train of circa 65 minutes. This will be delivered by constructing a short connecting line just south of Bicester where the Chiltern Railways London to Birmingham line crosses over the planned East – West railway line. This connection will facilitate wider journey options through the proposed East – West rail link between Oxford, Bletchley/Milton Keynes and onward journeys to East Anglia. Additional services will be provided between London Marylebone and Milton Keynes which will deliver journey times between High Wycombe and Milton Keynes


of 63 minutes compared to a current indirect journey times by train of circa 120 minutes. Handy Cross Hub Coachway / Park and Ride Planning permission has been granted for the Handy Cross Hub development which consists of a new Sports Centre, business park with associated land use and a Coachway / Park and Ride facility. The Coachway / Park and Ride interchange facility will incorporate a barrier controlled 400 space surface car park, covered waiting area, RTPI, designated stands for coaches, local bus services and park and ride services. The Coachway will provide an interurban regional link including routes to London and major airports. The park and ride service and diverted local bus services will provide a public transport link between High Wycombe town centre and the Coachway / Park and Ride. It is also expected that any future north-south coach services at the site will link High Wycombe to the Thames Valley area. Crossrail A new railway line known as ‘Crossrail’ is being developed and is planned for phased opening, with completion of the full route by 2018/9. Crossrail will provide a high frequency service linking Maidenhead in Berkshire to the west with Abbey Wood in East London via central London. This new infrastructure will provide significant benefits for Wooburn Town including improved connectivity with London and surrounding areas. The Bourne End rail station will provide access to the western end of Crossrail via existing services from Bourne End to Maidenhead. 4.5 Non-motorised Users

As part of the delivery of all ‘committed’ land use development sites, a package of transport measures for non-motorised users is delivered. These include new infrastructure such as Toucan crossings and widening of footways to provide shared use footway/cycle paths, and soft measures such as travel planning. The HW TCMP will provide improvements to the urban realm and pedestrian and cyclist accessibility within and through the town centre. This is achieved by changing the scale and design of key junctions within the town centre to fit their new roles, and delivering improvements to junctions including crossing provision on pedestrian desire lines. Footway provision is expanded and the overall design approach lends itself to reduced traffic speeds and a more attractive and accessible environment for pedestrians and cyclists. 4.6 Summary

This section has set out a forecast of traffic conditions in 2031. The growth in traffic volumes and changes in journey time and delay are described to provide a reference for the consideration of WDLP land use and transport mitigation scenarios. Key improvements in public transport and provision for non-motorised users are also described.


5 Land Use and Infrastructure Scenarios

5.1 Introduction

This section describes the land use and infrastructure scenarios that are assessed as part of this report. The Do Minimum forecast scenario described in section 4 reflects the ‘committed’ level of development and highway infrastructure for the High Wycombe area in 2031. Using this scenario as a reference, a number of land use development and transport infrastructure scenarios have been assessed. The assessment considers the full set of land use development sites holistically in order to ascertain the cumulative impact. These sites are first assessed ‘unmitigated’ in order to establish the areas most likely to be affected by the additional traffic generated by the new land use development. Following this initial assessment, the land use development is then tested with a number of potential packages of transport infrastructure measures (see section 6). The land use and infrastructure scenarios considered for Land North of Heath End Road (M40 Junction 3a) are described and assessed separately in section 7. 5.2 Land Use Developments

The land use development quantums have been provided by WDC and a set of potential transport infrastructure packages have been developed and agreed with BCC and WDC. A summary of the land use developments is presented in Table 5-A, and a location plan in Figure 5-A.

Residential Employment

ID Description Type No. of dwellings

Type

GFA (m2)

1 Abbey Barn South mixed 490 B1/B8 7000

2 Abbey Barn North residential 75

3 Gomm Valley and Ashwells 1 (40%) mixed 156 B1/B8 2000



6 Slate Meadow residential 180

7 Terriers Meadow residential 395

8 Wycombe Air Park Option 1 (Intensification) employment B1/D2 10700

9 Verco residential 100

10 Johnson & Johnson employment B1/B8 14000

11 Cressex Island employment A1/B8 13000

12 Terriers Lodge and Paddock Land residential 25

13 Netley Works, 89 Queens Road residential 47

14 Abercrombie Works, Abercromby Avenue residential 23

15 Land off West End St, rear of Desborough Ave residential 85

16 Rapid House, Bellfield Road residential 50

17 Brook Street residential 27

Table 5-A 2031 land use development sites


Figure 5-A Land use development site locations

Reserve sites are those referenced within the adopted Core Strategy (see section 2.2.2). The total provision expected from these land use developments is approximately 1,900 dwellings and an employment gross floor area of 50,000m2. Table 5-B provides the assumed trip rates for each land use class derived from relevant sites in the TRICS database. It is assumed that traffic generation from the hangars proposed at Wycombe Air Park would not be significant in the peak hours.

Land use class

Factor

AM (08:00- 09:00)

PM (17:00- 18:00)

Arrive Depart Arrive Depart

Privately owned housing per dwelling 0.161 0.438 0.412 0.241

Employment (B1/B8) per 100m2 0.681 0.111 0.091 0.569

Local shops (A1) per 100m2 4.419 4.122 4.925 4.932

Leisure (D2) per 100m2 0.560 0.443 1.565 1.175

Table 5-B Trip rates from TRICS database by land use class

Table 5-C shows the assumed traffic generation for each land use development site calculated from these trip rates. The only exception to this is for the Slate Meadow site, where the traffic generation is taken from an existing and available Transport Assessment (TA) previously agreed with the Highway Authority. The trip rates informing the traffic generation estimates have been established for the purposes of this assessment only. Local data would need to be collected to inform the development of revised trip rates. This would follow more detailed definition of the land use development as part of work associated with any possible planning application for each of the land use development sites. Trip rates would need to be agreed with the Highway Authority as part of this process.

Reserve Sites

Other Sites

N


AM

(08:00 – 09:00) PM

(17:00-18:00)

ID Description Arrive Depart Arrive Depart

1 Abbey Barn South 127 222 208 158

2 Abbey Barn North 12 33 31 18

3 Gomm Valley & Ashwells 1 (40%) 39 71 66 49



6 Slate Meadow 33 68 40 51

7 Terriers Meadow 64 173 163 95

8 Wycombe Air Park Intensification 22 12 40 36

9 Verco 16 44 41 24

10 Johnson & Johnson 95 16 13 80

11 Cressex Island 208 191 227 232

12 Terriers Lodge & Paddock Land 4 11 10 6

13 Netley Works, 89 Queens Rd 8 21 19 11

14 Abercrombie Works 4 10 9 6

15 Off West End St 14 37 35 20

16 Rapid House, Bellfield Rd 8 22 21 12

17 Brook Street 4 12 11 7

TOTAL 716 1049 1033 878

Table 5-C Traffic generation from land use development sites

5.3 Transport Mitigation Packages

Three transport mitigation packages have been developed to accompany the land use development sites. A set of schemes has been specified for individual sites or for broad geographical areas and these schemes have been combined into overall packages for the High Wycombe area. Further details of the transport mitigation packages are presented in Appendix F. Each package comprises ‘soft’ measures to encourage mode shift away from private car travel to public transport and non-motorised modes, and ‘hard’ measures including highway, walking and cycling infrastructure improvements. The three packages have been summarised as ‘Managed’, ‘Integrated’ and ‘Expanded’ and are described further below. These transport packages have been established for the purposes of the WDLP modelling assessment only. The assessment is a tool to assist in the development of the plan and not related to any specific planning application. The packages and their component schemes would require further consideration before being progressed towards implementation, equally it may emerge that other schemes are more appropriate. 5.3.1 ‘Managed’ Package (A)

This package is focused upon the control and calming of traffic using signals and a wider roll out of Urban Traffic Management Control (UTMC) systems with further traffic calming to ensure vehicle demand is managed onto appropriate strategic


routes. The aim is to manage and minimise the growth in private car trips and provide a range of alternative travel options for each site. The package is not designed to reduce overall travel times for vehicular traffic but to manage demand and minimise the adverse impacts of traffic growth. A 10% shift toward more sustainable modes is applied to internal trips from the land use development sites only. This assumes appropriate measures would be in place to realise this shift (see section 5.4). 5.3.2 ‘Integrated’ Package (B)

This package is focused upon a wider expansion and investment in public transport, walking and cycling in order to encourage greater levels of mode shift to more sustainable modes without expansion of highway capacity. The focus is on the provision of new and improved sustainable transport options at the new land use sites. However, it would also provide connections through existing residential areas to key destinations which would benefit existing residents of High Wycombe and minimise traffic growth. A 10% shift towards sustainable modes is applied to internal trips from the land use development sites and a further 6% is applied to internal trips in zones adjacent to the new land use sites. 5.3.3 ‘Expanded’ Package (C)

This package includes enhanced highway provision with improved capacity at junctions and new routes to accommodate and re-distribute vehicular demand. The expanded package assumes a lower level of mode shift than the other packages, but with more highway infrastructure measures. Based on the implementation of the sustainable travel elements of this package of measures, a mode shift of 6% is applied to internal trips from the land use development sites. Further phases of assessment are expected to be required to progress any of the packages (or their component parts) further. This will include taking into account the results of the modelling and public and stakeholder feedback. 5.4 Sustainable Travel / Mode Shift

Consistent with national and local transport policy, each of the transport packages includes a number of sustainable transport measures to discourage single occupancy private car travel. A different level of mode shift has been assumed for each package for modelling purposes. The starting point for establishing the mode shift assumptions is modelling work undertaken as part of previous Wycombe LDF studies. Consultants Halcrow derived a set of assumptions relating to a town-wide ‘smarter choices’ package in the published report TNTC2 (May 2010)22 associated with a modelling assessment in support of the DSA. The assumptions were informed by the results of the Sustainable Travel Towns Demonstration Project which realised a 10%+ reduction in private car trips as a result of the various smarter choices packages. The overall impact of the applied smarter choices assumptions in the Halcrow modelling was a reduction of around 3% in the total matrix and 6% for Wycombe-based trips. The approach taken in the assessment of the three transport packages conservatively applies these proportional reductions to the new land use development sites and (in package B) adjacent land use areas only. Traffic volume

22 TNTC2 High Wycombe Town Centre Masterplan Update (Halcrow, May 2010) http://www.wycombe.gov.uk/Core/DownloadDoc.aspx?documentID=2753


reductions have not been applied to wider zones as part of this assessment to avoid overestimating the possible effects of these measures. 5.4.1 Development Management Requirements

The transport packages and assumptions described in this section have been established for the purposes of the WDLP modelling assessment only. The assessment is a tool to assist in the development of the plan and not related to any specific planning applications. As per the policies in the adopted Core Strategy and the DSA, the planning and highway authorities set out their expectations of the development management process (see section 2.2.2). Any land use development will need to be accompanied by the necessary infrastructure, including solutions that deliver sustainable modes and minimise congestion. The measures set out in the three packages may form part of the solution to resolving transport issues associated with these land use development sites but this should not be considered an exhaustive list. Policy DM2 in the DSA sets out a range of measures that new land use developments would be expected to provide. These are set out in Table 5-D.


ID Transport Requirements Wider evidence

a)

Public Transport - Access to a high quality, fully accessible, attractive public transport service.

Smart-ticketing has been shown to increase public transport patronage by 6 – 20% (Booz & Co, 2009) Targeted public transport marketing and infrastructure improvements on Route 9 in Aylesbury increased patronage by 28% after 2 months and 42% after 8 months (DfT, 2005)

b)

A new or enhanced Public Transport service where development is not already served by a high quality attractive train or bus service. This may be provided directly or by way of a financial contribution, so that the service is maintained for a period of at least five years from an agreed occupation level.

c)

Walking and Cycling - Routes for pedestrians and cyclists which are designed to be safe, direct, attractive and convenient, according to the principles of community safety including that of natural surveillance from the built development;

In Aylesbury, Way-finding / branded signage increases cycle mode share from 3% in 2005 to 11% in 2007 (CILT, 2011)

d)

Travel Plans, in line with BCC guidance on Travel Plans, that set out the long term travel management strategy for an organisation or site, built on an appropriate package of measures aimed at promoting sustainable travel. They should include modal share targets and mitigation measures as well as the measures outlined below.

According to the DfT, workplace and school travel planning can reduce car trips by 18% and 10% respectively. Targeted marketing campaigns have been shown to reduce car trips by 8% (Moser and Bamberg, 2008).

e)

Car clubs - infrastructure in the form of parking spaces, drop off and pick up points, and, where appropriate car club vehicles, and/or subsidised cost of car club membership, and facilities for electric vehicle car charging points

Bucks Carshare is a car sharing website with around 600,000 members and is part of the Liftshare network. Founded in 1997 it is the UK’s largest and most successful car-sharing network.

f)

Car Sharing - Priority parking spaces for car sharers at developments that are primarily destinations (i.e. non-residential uses)

Table 5-D Policy DM2 Transport Requirements


6 Traffic Assessment and Appraisal

6.1 Introduction

This section presents the modelling results for the WDLP land use development and transport mitigation scenarios described in section 5. The impact of the unmitigated land use is assessed first, using the same criteria as for 2013 base and 2031 Do Minimum. In this report, this scenario is referred to as the ‘Do Something’ scenario. The impact of new land use developments is then considered in combination with the transport mitigation packages. For the purposes of this report, these are referred to as ‘Do Something mitigation package’ scenarios. These scenarios include three different levels of demand and supply mitigation, all with the same land use assumption as the unmitigated scenario. It is important to note that no assessment of viability has been undertaken as part of this study for the infrastructure associated with these scenarios. WDC are progressing a separate phase of work to assess broad viability aspects. The impact of the measures included in each of these scenarios is assessed against an appraisal framework, which includes a qualitative description of overall network performance, journey time impacts, traffic volume changes and consideration of the potential for travel by public transport and non-motorised modes. Additionally, there are a number of schemes proposed in some of the packages which offer significant new highway infrastructure in the form of new link roads. The impact and performance of these schemes is assessed in further detail using the HWHAM.

6.2 Modelling Results - Do Something Scenario

(a) Traffic Volumes

Figure 6-A to 6-D present the forecast traffic volumes in the 2031 AM and PM peak hours, and the forecast change in modelled traffic volumes comparing the Do Minimum with the unmitigated Do Something scenario. Appendix B presents the traffic forecast volumes in more detail. The overall pattern of traffic volumes within the High Wycombe area remains largely consistent with the pattern in the Do Minimum and base year, reflecting the dispersed pattern and relatively modest traffic growth across the highway network. The A404(S) corridor remains the most heavily used along with the section of the A40 West Wycombe Road between the Pedestal roundabout and Chapel Lane. The A4128 Hughenden Road route remains heavily used into and through the town centre, but the A404(N) accommodates lower levels of traffic volume south of Hamilton Road. The highest traffic volumes on the A40 London Road are to the west of Micklefield Road and to the east of Hammersley Road.


Figure 6-A 2031 Do Something (unmitigated) AM peak modelled flows

Figure 6-B 2031 Do Something (unmitigated) PM peak modelled flows

N


N



Figure 6-C 2031 AM peak Do Something traffic volume comparison

Figure 6-D 2031 PM peak Do Something traffic volume comparison

N


N



In terms of overall traffic growth for High Wycombe, there is forecast to be an increase of 4.1% in the AM peak and 4.6% in the PM peak associated with the new land use development. Overall, traffic volume increases are greater in the PM peak than the AM peak. The figures clearly illustrate the presence of new land use development, as the notable increases in traffic volumes are located in the vicinity of the new sites. This includes the southern quadrant area of High Wycombe, and routes including London Road, Abbey Barn Lane, Daws Hill Lane and Marlow Hill in particular. These routes all experience traffic volume increases as a result of new land use development at Abbey Barn South, Abbey Barn North and Gomm Valley in particular. Traffic distribution plots for the major development sites are presented in Appendix G. Traffic volume increases of note in the AM peak occur on Crest Road close to Handy Cross. There are also notable increases on Desborough Avenue, which offers a route to the town centre for new land use development in the southern quadrant, and Abbey Barn Lane, which is used by trips generated by Abbey Barn South and Abbey Barn North. There are comparatively minor increases on a number of other roads in the town, all due to the increased traffic generation from the new developments. Traffic volume increases in the PM peak include the M40 to the east of Junction 4. Consistent with the results for the AM peak, there are also traffic volume increases on Crest Road, Desborough Avenue and Abbey Barn Lane which occur for the same land use development reasons. Significant increases in traffic volume also extend to Marlow Hill, mainly due to traffic increases from the Abbey Barn developments (North and South), and on the A40 between Hatters Lane and Micklefield Road. The volume increase on the A40 is primarily a result of the presence of land use development at Gomm Valley, and also the reassignment of traffic from Micklefield Road and Hicks Farm Rise, both of which are subject to forecast traffic volume decreases. Consistent with the traffic volume changes demonstrated in the Do Minimum scenario, there are further increases in traffic volume on strategic routes including the A4010 and the Holmer Green Road / B474 Penn Road route to Beaconsfield. Traffic volumes on the A4094 in Wooburn Town do not change markedly as a result of the new land use development. (b) Journey Patterns

The Do Something land use development sites do not result in a significant change in strategic journey patterns within the High Wycombe area as there are limited alternative route choices available. The M40 continues to play an important role in distributing longer distance land use development traffic and desire lines continue to be focused on motorway junction access, in particular via M40 Junction 4 at Handy Cross. (c) Journey Time and Delay

Link speeds and junction delays for the unmitigated Do Something scenario are shown below:


Figure 6-E 2031 AM peak Do Something link speeds and delay

Figure 6-F 2031 PM peak Do Something link speeds and delay

N


N



Overall, the pattern of link speed and delay in the Do Something scenario is similar to the Do Minimum scenario. However, traffic growth as a result of the new land use development has resulted in decreases in speed and increases in delay across the network. On average, network speeds have reduced by 0.8mph to 19.7mph in the AM peak and by 1.5mph to 19.8mph in the PM peak. The number of road links with lower speeds has increased and there is a marginal reduction in link speed on all strategic corridors within the town. Table 6-A presents the 2031 corridor journey times and speeds compared to the Do Minimum scenario for the AM and PM peaks.

AM Peak PM Peak

ID. Description time mm:ss

time diff.

speed mph

speed diff.

time mm:ss

time diff.

speed mph

speed diff.

1 Handy Cross to West Wycombe 12:50 00:24 14.1 -0.5 15:51 01:12 11.4 -0.9

2 West Wycombe to Handy Cross 17:22 01:00 10.4 -0.6 15:27 01:22 11.7 -1.1

3 Handy Cross to Amersham Road 17:57 01:05 12.1 -0.8 24:15 03:25 8.9 -1.5

4 Amersham Road to Handy Cross 20:29 00:45 10.5 -0.4 16:20 00:57 13.2 -0.8

5 London Road inbound 12:54 00:44 11.4 -0.7 15:03 02:15 9.8 -1.7

6 London Road outbound 20:15 01:39 7.3 -0.6 15:40 01:54 9.4 -1.3

7 West Wycombe to Town 14:30 00:18 9.6 -0.2 12:55 01:00 10.8 -0.9

8 Town to West Wycombe 12:38 00:37 11.1 -0.6 14:27 00:52 9.7 -0.6

9 Hughenden Valley Road to Town 13:00 00:48 8.2 -0.5 06:37 00:16 16.2 -0.7

10 Town to Hughenden Valley Road 07:13 00:08 15.9 -0.3 11:07 00:41 10.3 -0.7

Table 6-A Journey time and speed - 2031 Do Something

Overall, the network-wide changes in link speed and junction delay in the AM peak are relatively limited. Compared with the AM peak Do Minimum speeds (Figure 4-E) there are decreases in link speed on Desborough Avenue, Abbey Barn Lane and John Hall Way in particular. These are all locations which experience an increase in traffic volume due to new land use development, and the fall in link speeds is an outcome of those increases. There are relatively few junctions which experience a notable increase in junction delay, reflecting the limited additional traffic volumes being added to the road network in comparison to the Do Minimum scenario. For the PM peak, the impact of the traffic volume increase on link speeds is similarly limited. Desborough Avenue and the A40 experience a reduction in average speeds consistent with the increase in traffic volume on those links. Changes in junction delays are also limited, although the Marlow Hill / Marlow Road junction experiences increases in delay of around one minute. It is recognised that a relatively limited network-wide impact may include a more significant local impact, in particular in the vicinity of new land use development. Any local negative impacts would be tackled by new land use developments as part of potential future planning application processes.


The M40 Junction 4 Handy Cross junction has been assessed in more detail using TRANSYT analysis (see Appendix E). The analysis indicates that the junction would continue to operate over-capacity on some approaches, but the junction signal timing strategy can be implemented to avoid queuing back on slip roads which would affect the operation of the M40. A summary of the analysis is presented in Table 6-B for the Do Something (unmitigated) scenario.

AM Peak PM Peak

Link Arm / Location

Do Minimum Do Something Do Minimum Do Something

RFC Queue RFC Queue RFC Queue RFC Queue

100/ 101

John Hall Way 78% 16 88% 18 92% 27 101% 53

200 Marlow Road 86% 19 78% 15 88% 20 113% 72

300/ 301

Marlow Hill 91% 18 97% 20 137% 87 149% 107

400/ 401

M40 Westbound Offslip 85% 29 95% 32 77% 19 85% 25

500/ 501

A404(M) (Northbound) 77% 10 78% 8 94% 20 91% 18

600 Marlow Bottom 103% 37 112% 65 97% 24 115% 79

701/ 702

M40 Eastbound Offslip 93% 23 90% 19 78% 13 91% 16

Table 6-B M40 Handy Cross TRANSYT analysis – summary of results

Note 1: RFC’s > 100% highlighted in red Note 2: Queue is mean maximum queue length in passenger car units (pcu’s) (d) Air Quality

An increase in traffic volume and corresponding reduction in speeds either as a result of congestion or as an intended feature of scheme design would result in a degradation in air quality (comparable in scale to the change in traffic demand). 6.3 Modelling Results - Do Something Mitigation Packages

6.3.1 Introduction

Three transport mitigation packages are described in section 5.3. This section describes the impact of each package on overall network performance, journey times along key corridors, development trip lengths, and the performance of the land use development access junctions. 6.3.2 Overall Network Performance

The following table demonstrates the overall performance of the network across each of the scenarios, and compares with the data for the 2031 Do Minimum and 2013 Base scenarios. Overall network vehicle-time (hours) and vehicle-distance (miles) is presented as well as congested vehicle-time (i.e. additional time due to delays) and average network speed. The scenario names are described further below.


Peak Scenario no. of vehicles

veh-miles veh-hrs

at freeflow

veh-hrs delayed

veh-hrs delay diff.

to DM

average speed (mph)

AM

2013 Base 35,852 267,065 6,488 4,113 -3,582 25.2

2031 DM 43,129 321,630 8,007 7,695 0 20.5

2031 DS 44,884 327,516 8,262 8,381 686 19.7

2031 DSm(A) 44,773 328,171 8,300 8,437 742 19.6

2031 DSm(B) 44,565 326,657 8,237 8,209 514 19.9

2031 DSm(C) 44,818 327,020 8,197 8,145 451 20.0

PM

2013 Base 34,482 284,116 6,582 4,176 -3,636 26.4

2031 DM 41,553 340,449 8,166 7,812 0 21.3

2031 DS 43,455 353,645 8,604 9,224 1,412 19.8

2031 DSm(A) 43,383 353,874 8,609 9,244 1,431 19.8

2031 DSm(B) 43,151 352,740 8,564 9,056 1,243 20.0

2031 DSm(C) 43,412 353,533 8,554 8,932 1,120 20.2

Table 6-C Network summary statistics

* Note 1: ‘veh’ = vehicles, ‘hrs’ = hours, ‘DM’ = Do Minimum, ‘DS’ = Do Something, ‘DSm’ = Do Something mitigation packages The data indicates the most significant increases in delay that occur in the network are from the 2013 base to the 2031 Do Minimum scenario (DM). The average speed reduces from 25.2mph in the AM base to 20.5mph in the 2031 AM Do Minimum and the PM peak speeds from 26.4mph to 21.3mph. The additional development in the Do Something (DS) scenario further decreases the average speed, by just under 1mph in the AM peak and 1.5mph in the PM peak. The Do Something mitigation packages (indicated in the tables by DSm(A), DSm(B) and DSm(C)) provide some improvement in average speed, however, the speeds are consistently below the Do Minimum level. Also notable is the vehicle-hours delayed data. This represents the time spent in the network by all vehicles due to delays, rather than travelling in free flow conditions. In both time periods there is a significant increase in delays between the base year and forecast do minimum (some of this is accountable by the fact there are more vehicles in the network to experience the delay, although most is due to actual increases in delay). There is a subsequent increase in delay in the Do Something scenario, before decreasing slightly compared to the Do Minimum scenario in Do Something mitigation scenarios B and C. 6.3.3 Journey Times

Figure 6-G and Figure 6-H show the AM and PM peak journey times for the three Do Something mitigation package scenarios compared with the Do Something scenario for the journey time routes shown in Figure 3-H. The journey times in the Do Something scenario are represented by ‘0’ minutes, and the performance of the three Do Something mitigation packages is compared against this scenario. These figures illustrate the effectiveness of each package in terms of mitigating the traffic growth impacts of the land use development.


Figure 6-G AM peak journey time difference with mitigation packages

Figure 6-H PM peak journey time difference with mitigation packages

6.3.4 Development Trip Lengths

Table 6-D presents the average trip length for all vehicular trips (origins and destinations), generated by the Core Strategy reserve sites and other larger WDLP


land use development sites. The two sites with the highest average trip length are employment sites. The two sites with the lowest averages are a mix of residential and employment land uses. Figures for the PM peak hour are presented only as the order of the results is similar for both peaks.

Land Use development site Development type

Ave. trip length (miles)

Abbey Barn North & South mixed 12.95

Gomm Valley & Ashwells mixed 13.11

Slate Meadow residential 13.82

Terriers Meadow residential 14.19

Johnson & Johnson employment 15.18

Wycombe Air Park employment 14.33

Cressex Island employment 14.00

Table 6-D PM Peak average trip length

For each land use development site, the average vehicular trip length is influenced by the proximity of the location to associated land use, and to the location of access junctions to the strategic road network. 6.3.5 Access Junctions

The access to the land use development sites included in the Do Something scenario is facilitated by both indicative new or existing junctions. The performance of the seven access junctions with the highest levels of delay is described below. Table 6-E shows the type of configuration assumed for each junction for the Do Something and three mitigation scenarios. Further details of network infrastructure changes assumed as part of the mitigation packages is presented in Appendix F.

Junction Description 2031 Do Something

2031 Do Something (A)

2031 Do Something (B)

2031 Do Something (C)

Abbey Barn (S) – Daws Hill Lane priority priority priority priority

Abbey Barn Lane (South) priority signals priority priority

Abbey Barn Lane (North) priority signals priority priority

Hammersley Lane/Gomm Valley priority priority priority priority

A40 London Road/Gomm Road signals signals signals signals

Kingshill Road/Terriers Meadow priority signals priority signals

Crest Road/Cressex Island roundabout roundabout roundabout roundabout

Table 6-E Type of junction serving land use sites in each scenario

Figure 6-I and Figure 6-J show that the delay per vehicle is generally higher when junctions are configured as signal controlled. This applies to the new junctions on Abbey Barn Lane and Kingshill Road.


Figure 6-I AM peak maximum delay per vehicle

Figure 6-J PM peak maximum delay per vehicle

The A40 London Road / Gomm Road junction is identified as experiencing relatively high levels of delay in the 2031 Do Minimum scenario. This junction is therefore constrained in terms of its function as an access junction from Gomm Valley to the wider road network without further improvement. The measures included in packages A and C both improve conditions at this junction. The junction of Terriers / Kingshill Road also experiences relatively high levels of delay and the improvement schemes in mitigation packages A and C achieve positive improvements in junction delay.


The other access junctions function well under the level of traffic volume forecast at each location. Figures 6-K and 6-L illustrate the total traffic volumes at each junction. Since the traffic generated by the land use developments is the similar in each scenario, the variations in the total throughput of the junctions shown in Figure 6-K and Figure 6-L is most likely due to local changes in routing through the road network.

Figure 6-K AM peak hour total number of vehicles using junction

Figure 6-L PM peak hour total number of vehicles using junction

6.4 Performance of Significant Schemes

The ‘Expanded’ mitigation package C includes two link road schemes which comprise relatively significant improvements to existing roads or the provision of


new roads. The first scheme is the upgrade of Winchbottom Lane between Heath End Road and Handy Cross from a single track road with passing places to a 2-way road along its whole length to provide an alternative route to M40 Handy Cross. This could relieve the currently congested route via Daws Hill Lane and the A404 Marlow Hill. The second scheme is a new link road connecting Clay Lane with the M40 Handy Cross junction via Ragmans Lane as an alternative to travelling through the southern quadrant of the town. Traffic flow routing output for each link is presented in Appendix H. The impact these improvements have on the local road network is detailed below in turn.

6.4.1 Winchbottom Lane

Figure 6-M shows the changes in AM peak traffic volume arising from the upgrade of Winchbottom Lane. Flow increases are shown in blue and decreases in green.

Figure 6-M 2031 AM peak flow differences - Winchbottom Lane The figure shows that the upgrade of the road does not result in any significant change in traffic volume on Winchbottom Lane. The intended purpose of the scheme is not achieved as traffic volumes are not forecast to reduce on the Daws Hill Lane route. Despite the upgrade to the route, Winchbottom Lane does not become an attractive route option for onward journeys to the A404(T) and the Thames Valley because of the need to negotiate a further four sets of traffic signals at the Handy Cross junction to reach the exit. In the AM peak there is a relatively small transfer of northbound trips away from the A404(T) onto Winchbottom Lane. The notable traffic volume changes indicated by Figure 6-M with the Winchbottom Lane scheme in place occur as a result of the introduction of the change in priority at Kingsmead Road / Abbey Barn Lane and improvements to the bridge just south of the junction. These changes alter routing decisions at the Heath End Rd / Swains Lane / Straight Bit junction, in particular as traffic transfers from the Swains Lane / Kingsmead Road route to the Heath End Road / Abbey Barn Lane route. The flow differences in the PM peak are shown in Figure 6-N below.

N


Figure 6-N 2031 PM peak flow differences - Winchbottom Lane There is a similar pattern of redistribution in the PM peak as in the AM, however the difference volumes are significantly higher. This is likely a result of the overall northbound direction of travel in the PM peak, and an increased volume of traffic is exiting the A404(T) at the Westhorpe interchange and utilising the upgraded Winchbottom Lane to access eastern and northern areas of High Wycombe. 6.4.2 Ragmans Lane

Figure 6-O presents the change in AM peak traffic volume arising from the implementation of a new link between Clay Lane and M40 Handy Cross.

Figure 6-O 2031 AM peak flow differences - Ragmans Lane

N

N


The Ragmans Lane link attracts around 600 vehicles in the AM peak, with the westbound direction most heavily used. This primary usage of this route is to provide an alternative link for traffic travelling between the M40 East and Marlow. The link also provides an alternative route to the M40 Handy Cross junction from Lane End and relieves routes within the Cressex area including the A4010 John Hall Way and Holmers Farm Way. A smaller proportion of traffic utilises the link in a westbound direction to access the southern quadrant area of the town via Clay Lane. Wider traffic volume changes within the southern quadrant result from other schemes provided as part of Package C, including changes to the Cressex Road / Cressex Link junction. The PM peak models show a similar pattern of traffic volume changes, albeit with the directions reversed. Traffic volume differences are shown in Figure 6-P below:

Figure 6-P 2031 PM peak flow differences - Ragmans Lane As with the AM peak, the new link provides a more direct route for traffic that previously would have used Wycombe Road and A404(T) to access Marlow from the north. This traffic redistribution may have a positive or negative impact upon key junctions within Marlow. There is also a notable re-assignment of eastbound trips from A4010 John Hall Way and Cressex Road / Holmes Farm Way, as the new link provides a more convenient connection to the M40 Handy Cross junction. Any future development of the link would require the typical assessments and appraisal undertaken for a scheme of this type. This would include consideration of its non-traffic, social and environmental context. 6.5 Mitigation Package Appraisal

Table 6-F summarises the impacts of the three transport mitigation package scenarios. The appraisal of impacts is limited to traffic and transport system performance categories including overall network performance, journey time and delay, traffic volumes and rat running, public transport and non-motorised users

N


only. The appraisal is intended to inform strategy development and emerging development principles.

Category 2031 Do Something (A –‘Managed’)

2031 Do Something (B – ‘Integrated’)

2031 Do Something (C – ‘Expanded’)

Positive

Overall Network Performance

- Facilitates wider roll-out of UTMC providing optimised junction performance

- Provides some improvement in overall network performance without significant new highway infrastructure

- Offers the greatest improvement in overall network performance

Journey Time and Delay

- Moderately beneficial on all corridors

- Significantly beneficial on some corridors

Traffic Volumes / Rat Running

- Additional control at junctions and speed management offers greatest potential to manage rat-running

- Potential for greatest overall reduction in traffic volumes

- Optimal network performance would encourage journeys onto primary routes. New links redistribute traffic.

Public Transport - Offers the greatest potential for public transport priority

- Greater potential for increasing public transport mode shares

- Public transport services would benefit from improved overall network performance

Non-motorised Users

- Greater potential for increasing non-motorised user mode shares

Negative


- Detrimental overall in traffic performance terms


- Detrimental to journey time on most corridors as signal-related delay is introduced

- Modest improvements in journey times and delay only

- Detrimental performance on a small number of corridors


- Potential to encourage additional traffic volumes and limit mode shift to sustainable modes

Public Transport - Least potential for increasing sustainable mode shares

Non-motorised Users

- Least potential for increasing non-motorised user mode shares

Table 6-F Summary appraisal table – mitigation packages


6.6 Summary

This section describes the results of the cumulative assessment of the WDLP land use. In terms of traffic volumes, an overall growth of between 4 and 5% is forecast in the Do Something scenario, in addition to Do Minimum traffic growth of around 20%. The changes in journey time and delay would be relatively modest compared to Do Minimum, however all corridors would experience an increase in journey times. In terms of the assessment of the mitigation packages, Package C – ‘Expanded’ provides the best result in terms of overall network speeds and delays, followed by Package B – ‘Integrated’ which is also beneficial. Package A – ‘Managed’ does not offer an overall quantified benefit, however the additional traffic control and speed reductions do offer a wider benefit as set out in the appraisal framework. The trip lengths and potential access junctions for the land use development sites have been assessed. As noted above, further assessment would be required to consider the progression of these schemes as understanding of the land use situation develops. Two particularly significant schemes included within Package C have been assessed in more detail. The Ragmans Lane link is shown to be beneficial in terms of providing an alternative route between the M40 Handy Cross and Marlow, and traffic volume reduction benefits in the southern quadrant area of High Wycombe. The Winchbottom Lane upgrade does not provide significant benefits for traffic movements, with a modest increase in northbound trips to destinations in eastern and northern High Wycombe the only notable outcome.


7 Land North of Heath End Road (M40 Junction 3a)

7.1 Introduction

This section presents the modelling results for a separate set of land use development and transport mitigation scenarios. These scenarios have been developed to consider the impact of new employment-led development on Land North of Heath End Road. The associated transport infrastructure (M40 Junction 3a) required to support the land use is also assessed (see section 7.3). It is important to note that no assessment of viability has been undertaken as part of this study for the infrastructure associated with this scenario. WDC are progressing a separate phase of work to assess broad viability aspects.

The scenarios presented in this section include land use and traffic generation for the unmitigated ‘Do Something’ scenario. The assessment follows a similar methodology to assessment of the land use development scenarios presented in section 6. It considers the effect of three packages of different levels of demand and mitigation options for Land North of Heath End Road (M40 Junction 3a).

The impact of the transport packages included in each of these scenarios is assessed against the appraisal framework described in section 6. This includes a qualitative description of overall network performance, journey times, traffic volumes, and consideration of the potential for travel by public transport and non-motorised users.

7.2 Land Use Development

WDC has identified the level of land use development to be assessed. A summary of the land use development is presented in Table 7-A.

Employment

ID Description Type No. of dwellings

Type

GFA (m2)

1 North of M40, west of Spring Lane employment B1/B8 10000

2 South of M40, west of Spring Lane employment B1/B8 5000

3 South of M40, east of Spring Lane residential 100

Table 7-A 2031 land use development sites – Land North of Heath End Rd

Table 7-B provides the assumed trip rates for each land use class derived from relevant sites in the TRICS database.

AM

(08:00 – 09:00) PM

(17:00-18:00)

Land Use Factor Arrive Depart Arrive Depart

Business Park per 100m2 1.775 0.259 0.227 1.571

Industrial Estate per 100m2 0.816 0.398 0.248 0.657

Table 7-B Trip rate assumptions – Land North of Heath End Rd

The total approximate provision expected from these land use developments includes an employment gross floor area of 15,000m2 and a total of 100 dwellings. The traffic generation assumptions for each of the land use development areas is


shown in Table 7-C based on a 50/50 split between Business Park and Industrial Estate land uses. The residential trip rates are consistent with those set out in the LMVR.

AM

(08:00 – 09:00) PM

(17:00-18:00)

ID Description Arrive Depart Arrive Depart

1 North of M40, west of Spring Lane 130 33 24 111

2 South of M40, west of Spring Lane 65 16 12 56

3 South of M40, east of Spring Lane 12 33 34 20

Total 207 82 70 187

Table 7-C Traffic generation – Land North of Heath End Rd

The trip rates informing the traffic generation estimates have been established for the purposes of this assessment only (as described in section 5.2). Revised trip rates would be required in further work that may be undertaken following more detailed definition of the land use development. 7.3 Strategic Transport Mitigation

An ‘Draft Economy Study and Employment Land Review – PBA, January 2014’ commissioned by WDC considered the employment needs of the District. The study considers the need for significant additional office space within the WDLP period and makes clear that transport accessibility is a key determinant of whether sites would be an attractive proposition for office and high quality industrial development. Access to the strategic road network is an important factor for commercially attractive employment land. A key objective for WDC as part of the WDLP development process is to set a policy context to redress a declining homes to jobs ratio, which has led to an increased proportion of ‘out-commuting’ from the District. Allocating or reserving employment land in attractive accessible locations is intended to limit further growth in out-commuting; which may cause transport issues related to unsustainable mode choice and increasing average journey lengths. Therefore, the locations available for new employment-led land use development are guided by accessibility, but are constrained by land availability within the High Wycombe area, much of which is an Area of Outstanding Natural Beauty (AONB). One of the options identified to contribute toward meeting employment need is Land North of Heath End Road (M40 Junction 3a). However, the attractiveness of significant additional employment-led land use at this location is constrained in transport terms due to the peak hour congestion on the A404 Marlow Hill corridor, A40 London Road corridor and on the route via Heath End Road / Daws Hill Lane. For the purposes of this assessment, the employment-led land use development scenarios in this section include a new motorway access junction as part of each transport infrastructure mitigation package. The junction is referred to as M40 Junction 3a and for this assessment would consist of a limited access motorway junction with eastbound offslip and westbound onslip only. This junction would complement the existing M40 Junction 3 which provides a westbound onslip and eastbound offslip only. The scenarios considered in this report all include strategic transport infrastructure in the form of an M40 Junction 3a as a component of employment-led land use at Land North of Heath End Road.


The scheme is in its very early stages; hence the schemes have not been developed in detail. Three transport packages are subject to assessment in this section which include upgraded connections between the south and north of High Wycombe with improved routes via Spring Lane and/or Abbey Barn Lane to connect with London Road (A40). A high level description of the three transport packages is given below and the packages are presented in Appendix F. Concept Package A: A new M40 Junction 3a consisting of west facing slips only which connects with new junctions with an upgraded Spring Lane. New junctions would be signal controlled to manage the flow and volume of traffic onto appropriate routes. A network of public transport, walking and cycling facilities is provided. Concept Package B: A new M40 Junction 3a consisting of west facing slips only which connects with new junctions with Spring Lane. Vehicular access to Kingsmead Road via Spring Lane is restricted and a connecting route between a northern M40 Junction 3a slip road junction and Abbey Barn lane is provided. A network of public transport, walking and cycling facilities is provided. Concept Package C: A new M40 Junction 3a consisting of west facing slips only which connects with new junctions with an upgraded Spring Lane. A new route to London Road at Gomm Road is provided via Spring Lane and Kingsmead Road. Additional highway capacity is provided to accommodate local and through traffic movements in the area. A network of public transport, walking and cycling facilities is provided. At this stage no formal assessment of the potential for induced traffic demand has been undertaken. Induced demand would result in additional traffic volumes within the area as a result of the provision of additional road network capacity. Induced demand would potentially reduce the benefits of any major new highway schemes.

7.4 Modelling Results – Land North of Heath End Road (M40 J3a)

(a) Traffic Volumes

Figures 7-A to 7-D present the forecast traffic volumes for the 2031 AM and PM peak hours, and the forecast change in modelled traffic volumes compared to the Do Minimum scenario. The results for mitigation package A only are presented to illustrate the strategic traffic volumes and differences, as the overall results are similar for each package. Local variation in the traffic volumes between each transport package is described later in this section. Appendix B presents the traffic forecast volumes in more detail. A supplementary analysis of the traffic volume impacts on the M40 has been undertaken. This analysis has considered the sensitivity of forecast traffic volumes to changes in the model speed-flow curve assumptions. The basis for and results of the sensitivity test is set out in Appendix I. In terms of overall traffic growth for High Wycombe, there is forecast to be an increase of 4.7% in the AM peak and 5.2% in the PM peak associated with the new land use development compared with the Do Minimum scenario.


Figure 7-A 2031 Land North of Heath End Rd (A) AM peak modelled flows

Figure 7-B 2031 Land North of Heath End Rd (A) PM peak modelled flows

N


N



Figure 7-C 2031 AM Land North of Heath End Rd (A) traffic volume comparison

Figure 7-D 2031 PM Land North of Heath End Rd (A) traffic volume comparison

N


N



There are a number of locations where the traffic volume changes that can be attributed directly to new land use development, including the A404 Amersham Road in the vicinity of Terriers, Crest Road and Holmers Farm Way in the southern quadrant and the A40 London Road in the vicinity of Gomm Valley. However, the M40 Junction 3a scheme delivered as part of Land North of Heath End Road has markedly altered the pattern of traffic volume and growth within High Wycombe more generally. The most significant impacts are on the M40 and in the southern and eastern areas of the town. The westbound M40 Junction 3a onslip is forecast to accommodate around 900 – 1150 vehicles in the AM peak and 800 – 950 vehicles in the PM peak. The eastbound offslip is forecast to accommodate around 500 - 600 vehicles in the AM peak and 900 – 1050 vehicles in the PM peak. Figure 7-E presents the traffic distributions associated with the westbound onslip (AM peak) and eastbound offslip (PM peak), representing the peak with the highest traffic volume in each case. The blue bars illustrate the routing of journeys using each slip, and the purple bar highlights the location of the slip road. The pattern of movement for each slip is similar for the opposite peak hour.

Figure 7-E M40 Junction 3a slip road traffic distribution (Package A) The junction provides access for traffic associated with the Land North of Heath End Road, primarily from wider areas to the west including Oxfordshire and to the south including the Thames Valley. Around 5% of traffic volumes using the slip roads is associated with Land North of Heath End Road. It is notable that the dominant flow of traffic is away from the junction in the AM peak and toward the junction in the PM peak. The remaining 95% of traffic utilising the slip roads re-routes from other areas as a result of the vehicular accessibility benefits and journey time savings provided by the scheme. The junction is utilised in particular by traffic with origins and destinations in Flackwell Heath, eastern and northern High Wycombe, the southern quadrant and areas adjacent to the A4094 including Wooburn Town. Potential land use developments in the southern quadrant and Gomm Valley also benefit from the new junction. This would also be expected to play a part in mitigating the transport

Westbound Onslip – AM Peak

Eastbound Offslip – PM Peak


impact of land use development at Land North of Heath End Road (M40 Junction 3a). The introduction of M40 Junction 3a scheme results in a significant increase in traffic volume on the M40 to the east of Junction 4, with corresponding reductions for the eastbound offslip at Handy Cross, and a small reduction towards Junction 3. There is also a notable reduction in traffic utilising the dedicated slip road from the A404(T) to the M40(west) at Handy Cross, in particular associated with trips from the Bourne End / Wooburn Town area. A number of local roads within High Wycombe are affected significantly by the Land North of Heath End Road land use development and associated M40 Junction 3a. There is a notable increase of traffic volume between the M40 Loudwater junction and Land North of Heath End Road as a result of traffic travelling to and from the development site from the east. This affects the A40 London Road, Kingsmead Road, Abbey Barn Road, Abbey Barn Lane and Spring Lane in particular. The key areas where traffic volumes reduce significantly as a result of the M40 Junction 3a scheme include the route from Heath End Road (west of Spring Lane), which continues along Daws Hill Lane to the A404 Marlow Hill toward the M40 Junction 4 at Handy Cross. The scheme provides significant traffic volume reduction in these areas with a two-way total traffic volume of around 400 vehicles re-routed away from this area. The impact in the immediate vicinity of Land North of Heath End Road (M40 Junction 3a) varies considerably depending upon the particular mitigation package. Table 7-D sets out the forecast traffic volumes for key road links that vary most significantly as a result of the transport packages.

AM (08:00 – 09:00) PM (17:00 – 18:00)

Do Min.

Diff. from DM Do

Min.

Diff. from DM

Location A B C A B C

Abbey Barn Lane (S Kingsmead) 838 -72 450 -141 815 -73 355 -106

Abbey Barn Road (N Kingsmead) 1645 294 211 -528 1300 450 516 -337

Spring Lane (S of Kingsmead Rd) 153 750 -153 1030 22 1011 -22 1203

Kingsmead Rd (W of Spring Lane) 939 306 -304 -469 1012 97 -23 -613

Kingsmead Rd (E of Spring Lane) 805 179 -173 -116 986 66 3 -327

London Road (W of Gomm Rd) 1550 137 124 270 1378 295 -65 532

Table 7-D Two-way traffic volume differences with mitigation packages

Note 1: Traffic volume increases >100 shown in red and decreases >100 shown in green.

A key difference in the results of the three mitigation packages relates to the strategy for connecting the M40 Junction 3a with the A40 London Road corridor. Package A retains the existing configuration of routes, with access possible via an upgraded Abbey Barn Lane and Spring Lane. There is a marked increase in traffic volume on both routes. In Package B, the traffic volume impact on Spring Lane is eliminated by closing this route. This reduces traffic on Kingsmead Road particularly in the AM peak, but increases the volume of traffic significantly on Abbey Barn Lane and Abbey Barn Road as all local north-south traffic is routed along this route.


In Package C, a new link is provided to connect Spring Lane with the A40 London Road / Gomm Road junction, which results in the highest traffic volumes on Spring Lane of all scenarios. Accordingly, traffic volumes have reduced markedly on Abbey Barn Lane, Abbey Barn Road and on Kingsmead Road. The Spring Lane – London Road link included as part of Package C is forecast to accommodate around 300 vehicles northbound and 700 vehicles southbound in the AM peak, and around 600 vehicles northbound and 350 southbound in the PM peak. The route serves traffic from a range of local areas including Tylers Green / Penn, the town centre, eastern High Wycombe and Flackwell Heath. The route also attracts longer distance traffic, particularly associated with areas to the west via the M40 and the south via the A404(T). Traffic distribution diagrams are presented in Appendix H. (b) Journey Patterns

Overall, the implementation of the strategic transport infrastructure associated with Land North of Heath End Road results in a significant shift of journey patterns within southern and eastern High Wycombe as shown in Figures 7-C, 7-D and 7-E. The M40 Junction 3a provides more direct routes for traffic associated with eastern and southern areas of High Wycombe. Flackwell Heath, Wooburn Town and Bourne End would benefit in terms of improved accessibility to the M40 for journeys to the west via Oxfordshire and the south via the Thames Valley. However, additional traffic is attracted to these areas, in particular through Flackwell Heath, as a result of both land use and routing changes. The provision of the M40 Junction 3a provides an alternative north-south route in the eastern area of the town, which results in a redistribution of traffic volumes away from the A404 Marlow Hill and Daws Hill Lane routes. The junction also provides additional journey routing options which could lead to improved network resilience. (c) Journey Time and Delay

The forecast link speeds and junction delays for Land North of Heath End Road are presented for transport package C and shown in Figures 7-F and 7-G. The overall strategic impacts of package C are representative of the other packages. Any key differences are described later in this section. Overall, there is a general reduction in link speed across the network as a result of increased traffic volumes from the new land use development. On average, network speeds have reduced by 0.6mph to 19.9mph in the AM peak and by 1.1mph to 20.2mph in the PM peak compared with the Do Minimum scenario. There are a number of locations where link speed improves, in particular on the A40 London Road, A404 Marlow Hill and Daws Hill Lane.


Figure 7-F 2031 AM Land North of Heath End Rd (C) link speeds and delay

Figure 7-G 2031 PM Land North of Heath End Rd (C) link speeds and delay In terms of junction delays, a number of locations benefit from the impact of the M40 Junction 3a scheme. These include the A404 Marlow Hill junctions with Daws Hill

N



N


Lane and Marlow Road. The different schemes included in the three mitigation packages result in different levels of performance, in particular on the A40 London Road corridor. The key differences in junction delays (seconds) for each transport mitigation package are set out in Table 7-E.

AM (08:00 – 09:00) PM (17:00 – 18:00)

Location DM A B C DM A B C

A40 / Gomm Road <180 >180 >180 <120 <90 <90 <90 <120

A40 / Abbey Barn Lane <180 <60 <150 <120 <150 <30 <90 <60

A40 / Micklefield Road <90 <180 <180 >180 <150 >180 >180 >180

Table 7-E Key changes in junction delay – Land North of Heath End Rd

Note 1: Delay increases relative to Do Minimum (DM) shown in red and decreases relative to DM shown in green.

The A40 / Abbey Barn Lane junction benefits from each package of transport measures, as the impact of the Land North of Heath End Road land use is mitigated. There is a mix of positive and negative impacts on the A40 / Gomm Road junction, with delay generally increasing in transport packages A and B. The provision of a four arm junction in package C provides a positive impact in the AM peak and a negative impact in the PM Peak, resulting from the changes in traffic volumes at this location. The A40 / Micklefield Road junction is generally adversely affected as a result of the Land North of Heath End Road development traffic and re-routed traffic volumes associated with the M40 Junction 3a scheme. Figures 7-H and 7-I the AM and PM peak journey times for the three mitigation package scenarios compared with the unmitigated Do Something scenario for the routes shown in Figure 3-H. These illustrate a range of positive and negative impacts on the A40 London Road corridor but overall most corridors experience improvements in journey time as a result of the M40 Junction 3a scheme, in particular the north-south route from Handy Cross to Amersham Road.


Figure 7-H AM peak journey time difference with mitigation packages

Figure 7-I PM peak journey time difference with mitigation packages


(d) Air Quality

An increase in traffic volume and corresponding reduction in speeds, either as a result of congestion or as an intended feature of scheme design would result in a degradation in air quality. The areas that would benefit and dis-benefit as a result of Land North of Heath End Road and M40 Junction 3a are likely to reflect the areas of significant change in traffic volume and link speed described above. 7.5 Overall Network Performance

Table 7-F demonstrates the overall performance of the network for each of the scenarios, and compares the data with the 2031 Do Minimum scenario. Overall network vehicle-time (hours) and vehicle-distance (miles) are presented, as well as congested vehicle-time (i.e. additional time due to delays) and average network speed.

Peak Scenario no. of vehicles

veh-miles

veh-hrs at freeflow

veh-hrs delayed

veh-hrs delay diff. to

DM

average speed (mph)

AM

2013 Base 35,852 267,065 6,488 4,113 -3,582 25.2

2031 DM 43,129 321,630 8,007 7,695 0 20.5

2031 DS# 44,884 327,516 8,262 8,381 686 19.7

2031 LNoHER(J3a)-(A)* 45,161 328,230 8,255 8,362 667 19.8

2031 LNoHER(J3a)-(B)* 45,134 328,285 8,248 8,371 676 19.8

2031 LNoHER(J3a)-(C)* 45,166 327,854 8,229 8,263 568 19.9

PM

2013 Base 34,482 284,116 6,582 4,176 -3,636 26.4

2031 DM 41,553 340,449 8,166 7,812 0 21.3

2031 DS# 43,455 353,645 8,604 9,224 1,412 19.8

2031 LNoHER(J3a)-(A)* 43,701 353,692 8,543 8,994 1,182 20.2

2031 LNoHER(J3a)-(B)* 43,681 353,836 8,576 9,030 1,218 20.1

2031 LNoHER(J3a)-(C)* 43,705 353,558 8,535 8,975 1,163 20.2

Table 7-F Network summary statistics – Land North of Heath End Rd

*Note 1: Land North of Heath End Rd (M40 Junction 3a) transport mitigation package scenarios #Note 2: Do Something scenario (unmitigated) excluding Land North of Heath End Rd (M40 Junction 3a)

The average speed reduces from 25.2mph in the AM base to just below 20mph and from 26.4mph in the PM base to just above 20mph in the Land North of Heath End Road scenarios. The impact of the Land North of Heath End Road scenario is mitigated by the transport packages in comparison to the unmitigated Do Something scenario, with improved overall network speed by up to 0.2mph in the AM peak and up to 0.4mph in the PM peak. Network speeds remain lower than the Do Minimum scenario, and markedly so in comparison to the existing 2013 base year conditions. 7.6 Mitigation Package Appraisal

Table 7-G summarises the impact of the three transport mitigation package scenarios. The appraisal is limited to traffic and transport system performance categories including overall network performance, journey time and delay, traffic volumes and rat running, and potential for travel by public transport and non-motorised modes.


Category 2031 LNoHER (M40 J3a) (A –‘Managed’)

2031 LNoHER (M40 J3a) (B – ‘Integrated’)

2031 LNoHER (M40 J3a) (C – ‘Expanded’)

Positive


- Facilitates wider roll-out of UTMC providing optimising junction performance - Provides improvement in overall network performance

- Provides some improvement in overall network performance without significant new highway infrastructure

- Offers the greatest improvement in overall network performance


- Beneficial on most corridors, significantly so on Handy Cross to Amersham Road




- Additional control at junctions and speed management offers greatest potential to manage rat-running

- Potential for greatest overall reduction in traffic volumes

- Optimal network performance would encourage journeys onto primary routes. New links redistribute traffic.

Public Transport - Offers the greatest potential for public transport priority

- Greater potential for increasing public transport mode shares

- Public transport services would benefit from improved overall network performance

Non-motorised Users

- Greater potential for increasing non-motorised user mode shares

Negative


- Requires the most additional infrastructure to achieve network performance improvements


- Detrimental notably on London Road corridor outbound in PM peak

- Some modest increases in journey time

- Detrimental notably on London Road corridor inbound in AM peak


- Potential to encourage additional traffic volumes and limit shift to more sustainable modes



Public Transport - Least potential for increasing sustainable mode shares

Non-motorised Users

- Least potential for increasing non-motorised user mode shares

Table 7-G Summary appraisal table – Land North of Heath End Rd mitigation packages


7.7 Summary

This section describes the results of the Land North of Heath End Road (M40 Junction 3a) assessment. In terms of traffic volumes, an overall growth of between 4.7 and 5.2% is forecast for the three scenarios tested, in addition to Do Minimum traffic growth of around 20%. The overall changes in journey time and delay would be relatively modest; however there would be significant changes in journey patterns and journey time and delay on key routes as a result of the impact of M40 Junction 3a. In terms of the assessment of the mitigation packages, Package C – ‘Expanded’ provides the best result in terms of overall network speeds and delays, followed closely by Package A – ‘Managed’ and Package B – ‘Integrated’ which are both beneficial in comparison to an unmitigated ‘Do Something’ scenario. The transport packages do not fully mitigate the impact of the land use development relative to a Do Minimum scenario. This assessment represents an early stage in the WDLP development process. Further studies would be required, to consider how to combine the effective elements of the transport mitigation packages to improve overall network performance and produce optimal travel conditions, as they are developed further. This would include deliverability, wider transport impacts and non-transport effects (including environmental and social factors).


8 Summary and Conclusion

8.1 Overall Summary

Wycombe District Council (WDC) is developing a new Local Plan for the District. Once adopted, the Plan (WDLP) will replace the adopted Core Strategy (2008) as well as the saved policies from the existing Local Plan (2004). The adopted Core Strategy includes a number of ‘Reserve Locations for Future Development’ (Policy CS8) which are included within the assessment of a wider range of land use development sites in section 6 of this report. The WDLP will sit alongside the Delivery and Site Allocations (DSA) Plan for Town Centres and Managing Development document. Jacobs has been commissioned by Buckinghamshire County Council (BCC) and WDC to undertake a transport study. The study provides an evidence base informed by traffic modelling, which demonstrates the implications of potential new land use development and considers a range of potential associated transport infrastructure schemes. The evidence base will support and inform the development of the new WDLP. The High Wycombe area is characterised by relatively high levels of vehicle (cars and vans) ownership. Travel to work mode shares are dominated by private car travel. The road network in the area is configured around five radial strategic corridors including the A40, A404 and A4128 and the A4094 which connects High Wycombe with Bourne End / Wooburn Town. Traffic movements are influenced by the proximity of the area to the M40 which results in a complex mix of longer distance through-traffic and local journeys. A network of public transport routes is present in the area and many longer distance journeys are also served by High Wycombe and Bourne End railway stations. Many of the strategic corridors typically experience peak time congestion with reduced link speeds and increased vehicular delays, despite reductions in traffic volume in recent years. A number of local routes experience reduced speeds associated with link or junction congestion. Local experience also suggests occasional severe events associated with incidents on the M40 for example. However, congestion is typically limited to a proportion of the peak hour only and link speeds quickly return to free flow operation. A ‘Do Minimum’ transport model scenario has been developed which includes committed land use and transport infrastructure schemes. This scenario shows that traffic volumes and delays are forecast to increase by around 20% by 2031 with overall journey speeds reducing by around 5mph compared with current conditions. This scenario provides a reference against which a range of land use ‘Do Something’ and transport mitigation packages are considered. The Do Something scenario results in a further increase in traffic volumes of 4 – 5% and further overall reductions in journey times of around 1mph. Three potential transport packages have been developed which include a range of schemes and mitigation measures. These improve a number of key corridor’s journey times and improve the potential for travel by public transport and non-motorised modes. A further separate land use development scenario is considered consisting of employment-led development at Land North of Heath End Road with an associated


M40 Junction 3a scheme. The M40 scheme mitigates the overall (highway) impact of the additional land use development in this separate scenario and provides new routing options which could lead to improved network resilience. However, the significant change in traffic distribution results in a number of local benefits and dis-benefits in terms of link speeds and delays. The scheme is in its very early stages; hence the packages have not been developed in detail and no assessment of viability has been undertaken as part of this study. 8.2 Conclusion

This transport study has set out the strategic impacts of new land use development in the High Wycombe area. A set of transport mitigation packages have been developed which include different strategies for managing, accommodating and mitigating the impacts of new land use development for two separate land use scenarios. The transport mitigation packages provided as part of the Do Something scenario offer a range of travel benefits within the High Wycombe area. Transport package C provides the best results in overall network performance terms, however, packages B and C offer wider benefits for alternative travel modes that serve to minimise the potential for an increasing dominance of the private car. Traffic conditions in terms of link speeds, journey times and delays are forecast to worsen overall and these packages do not fully return overall network performance to Do Minimum or base year levels. The potential strategic infrastructure scheme introduced as part of the Land North of Heath End Road scenario provides overall benefits for vehicular traffic relative to the Do Something (unmitigated) scenario but also local dis-benefits for some areas particularly associated with traffic re-routing. Consideration of how to minimise the forecast growth in traffic will be important as the ‘Do Minimum’ traffic growth is the most important factor influencing journey times and junction delays. There is evidence23 which some experts suggest shows that the levels of traffic growth forecast by the various industry-standard databases will not materialise in future, and therefore transport conditions would be significantly better than set out in this report. However, the forecasts undertaken follow industry best practice and provide the most appropriate basis for planning at this stage. This assessment represents an early stage in the WDLP development process. Further consideration of how best to combine the effective elements of the transport mitigation packages to improve overall network performance and produce optimal travel conditions will be required. This process will be informed by public and stakeholder feedback on the initial studies. It will need to consider a wider range of transport and non-transport factors, which will determine measures’ overall appropriateness and deliverability.

23 Peak car use in Britain http://www.parliament.uk/documents/commons-committees/transport/POST%20briefing%20on%20peak%20car.pdf

wycombe district local plan - high wycombe area ... · document title: high wycombe area –...

Documents