Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham...

44
Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3 Wiltshire Council 23 October 2014

Transcript of Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham...

Page 1: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3 Wiltshire Council

23 October 2014

Page 2: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951

Notice

This document and its contents have been prepared and are intended solely for Wiltshire Council’s information and use in relation to the Chippenham Site Allocations Plan.

Atkins Ltd assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents.

This document has 44 pages including the cover.

Document history

Job number: 5131951 Document ref: Final

Revision Purpose description Originated Checked Reviewed Authorised Date

Rev 1.0 Draft for client comment KQ/TP PC - - 11/06/14

Rev 2.0 Draft KQ/PC TP - - 22/07/14

Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14

Final Final for issue TP/KQ AP PC JFC 23/10/14

Page 3: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951

Table of contents

Chapter Pages

1. Introduction 5 Background 5 Purpose of Evidence Paper 6 Structure of Evidence Paper 7

2. Methodology 8 Overview 8 Key Theme 1 – Sustainable Access 9 Key Theme 2 – Highway Access 10 Key Theme 3 – Wider Transport Opportunities 11 Overall Assessment 11

3. Key Theme 1 – Sustainable Access 12 Introduction 12 Ease of Access to Key Services by Non-Motorised Modes 14 Potential for Access by Public Transport 21 Overall Assessment for Key Theme 1 23

4. Key Theme 2 – Highway Access 26 Introduction 26 Network Impacts 26 Potential Access from the Primary Route Network 29 Overall Assessment for Key Theme 2 32

5. Key Theme 3 – Wider Transport Opportunities 35 Introduction 35 Key Theme 3 Qualitative Assessment 36 Key Theme 3 Summary 37

6. Key Themes 1-3 Overall Assessment 39

7. Strategic Area Interdependencies 41 Introduction 41 Dependency Analysis 41 Potential Development Scenarios 43 Summary 43

Page 4: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951

Tables Table 3-1 Access to Town Centre Categorisation 14 Table 3-2 Ease of Access to Town Centre by Non-Motorised Modes Assessment 15 Table 3-3 Access to Secondary Schools Categorisation 16 Table 3-4 Ease of Access to Secondary Schools by Non-Motorised Modes Assessment 17 Table 3-5 Access to the Hospital Categorisation 18 Table 3-6 Ease of Access to the Hospital by Non-Motorised Modes Assessment 19 Table 3-7 Access to Employment Areas Categorisation 19 Table 3-8 Ease of Access to Employment Areas by Non-Motorised Modes Assessment 20 Table 3-9 Proximity to Public Transport Corridors Categorisation 21 Table 3-10 Potential for Access by Public Transport Assessment 22 Table 3-11 Overall Assessment for Key Theme 1 – Absolute Scores 24 Table 3-12 Overall Assessment for Key Theme 1 – Comparative Performance 24 Table 4-1 Network Impacts Categorisation 28 Table 4-2 Network Impacts Assessment 29 Table 4-3 PRN Access Categorisation 30 Table 4-4 Potential Access from the PRN Assessment 31 Table 4-5 Overall Assessment of Key Theme 2 – Absolute Scores 33 Table 4-6 Overall Assessment of Key Theme 2 – Comparative Performance 33 Table 4-7 Overall Assessment of Key Theme 2 34 Table 5-1 Overall Assessment of Key Theme 3 38 Table 6-1 Summary of Assessments 40 Table 7-1 Dependency Matrix 41

Figures Figure 1-1 Strategic Areas identified by Wiltshire Council 5 Figure 1-2 Strategic Areas, Indicative Boundaries 6 Figure 2-1 Strategic Area Assessment Themes and Categories 9 Figure 3-1 Locations for Key Theme 1 13 Figure 3-2 Ease of Access to Town Centre by Non-Motorised Modes Map 15 Figure 3-3 Ease of Access to Secondary Schools by Non-Motorised Modes Map 17 Figure 3-4 Ease of Access to the Hospital by Non-Motorised Modes Map 18 Figure 3-5 Ease of Access to Employment Areas by Non-Motorised Modes Map 20 Figure 3-6 Potential for Access by Public Transport Map 22 Figure 3-7 Key Theme 1 Heat Map – Sustainable Access 23 Figure 4-1 Congested Corridors with Constraints Limiting Mitigation 27 Figure 4-2 Network Impacts Map 28 Figure 4-3 Potential Link Roads Providing Access from the PRN 30 Figure 4-4 Access to the PRN Map 31 Figure 4-5 Key Theme 2 Heat Map – Highway Access and Impacts 32 Figure 6-1 Strategic Area Assessment – Venn Diagram 40 Figure 7-1 Strategic Area Assessment – Final Venn Diagram 42

Page 5: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 5

1. Introduction

Background 1.1. The Examination in Public for Wiltshire’s emerging Core Strategy1 highlighted certain areas

where the underlying evidence requires strengthening. One of the key areas for strengthening relates to the strategic site assessments and allocations for Chippenham. In particular the Planning Inspector requires Wiltshire Council to ensure there is a robust and equitable consideration of reasonable alternatives, taking account of possible infrastructure improvements that could be delivered to improve access. Wiltshire Council is therefore preparing revised documentation (including the Chippenham Site Allocations DPD).

1.2. Wiltshire Council has identified five Strategic Areas (A-E), covering land surrounding the existing urban area to the east of the A350, as shown in Figure 1-1. The areas are bounded by natural or major human features, such as the River Avon, railway line, and main roads (A350 / A4). The Strategic Areas are to be assessed against a wide range of economic, environmental and social criteria, including transport and accessibility. Indicative boundaries for the five areas, as adopted for the transport and accessibility assessments, are shown in Figure 1-2.

Figure 1-1 Strategic Areas identified by Wiltshire Council2

1 The Examination in Public took place during summer 2013. 2 Diagram produced by Wiltshire Council as part of revised Core Policy 10.

Page 6: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 6

Figure 1-2 Strategic Areas, Indicative Boundaries3

Purpose of Evidence Paper 1.3. This Evidence Paper presents the output of the first (high level) transport and accessibility

assessment stage undertaken by Atkins, identifying the Strategic Areas which have, in relative terms, the most preferable potential transport and accessibility attributes. A future second assessment phase will require a more detailed analysis of specific scenarios and sites within each of the Strategic Areas. Map based representation has been used throughout this Evidence Paper to allow Wiltshire Council to demonstrate and articulate why certain areas might be preferable to others in transport and accessibility terms.

3 Indicative boundaries have been defined solely for the analysis contained in this Evidence Paper. They are based on

information held by Wiltshire Council on land parcels currently being promoted for development by land owners and developers. The areas exclude Flood Zones 2 and 3 as defined by the Environment Agency.

Page 7: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 7

1.4. Wiltshire Council has prepared a revised draft version of Core Policy 10 (Chippenham Area Strategy) as part of its overall documentation review. Core Policy 10 sets out six criteria that will be used to guide decisions on areas for growth and on the site allocations within the DPD. Two of the six criteria are clearly transport related4:

Criterion 3: Offers wider transport benefits for the existing community, has safe and convenient access to the local and primary road network and is capable of redressing traffic impacts, including impacts affecting the attractiveness of the town centre; and

Criterion 4: Improves accessibility by alternatives to the private car to the town centre, railway station, schools and colleges, and employment.

1.5. The method applied in this first transport and accessibility assessment stage is aligned to the two transport-related criteria of revised Core Policy 10.

Structure of Evidence Paper 1.6. The remainder of this Evidence Paper is structured as follows:

Chapter 2 describes the method that has been used to assess the transport and accessibility characteristics of the Strategic Areas;

Chapter 3 assesses the Strategic Areas in terms of their accessibility by alternatives to the private car (linked closely to criterion 4 of revised Core Policy 10);

Chapter 4 assesses the Strategic Areas in relation to highway access and network (traffic) impacts (linked closely to criterion 3 of revised Core Policy 10);

Chapter 5 identifies the wider transport opportunities for existing communities that may be brought about as a result of development in the Strategic Areas (linked closely to the first part of criterion 3, revised Core Policy 10);

Chapter 6 summarises the overall transport and accessibility assessments; and

Chapter 7 identifies likely development interdependencies (relating to transport and accessibility) between the Strategic Areas and reviews the assessments in light of these interdependencies.

4 Criteria reproduced directly from revised Core Policy 10, produced by Wiltshire Council.

Page 8: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 8

2. Methodology

Overview 2.1. The Strategic Area transport and accessibility assessment is focused on three key themes:

2.2. The method is focused deliberately on transport and accessibility themes, as other themes (such as those relating to environmental, social, and wider economic impacts) are to be assessed by Wiltshire Council in parallel.

2.3. The three transport and accessibility themes have been framed to consider the ‘potential’ that an area may have and the ‘opportunities’ that developing the area might offer. This avoids introducing an assessment bias to simply favour areas that are easily accessible from the existing transport network. It ensures that all areas are considered in an equitable manner.

2.4. The Strategic Areas (A-E) have been assessed against the three key themes and then placed into one of the eight categories shown in Figure 2-1. The most favourable Strategic Areas (solely in terms of transport and accessibility) sit within Category 1. Any area that is assessed to fall within Category 1 will have the following transport and accessibility attributes:

Strong or moderate potential for easy access to the area from public transport networks, and to/from Chippenham town centre (rail station, college and retail) and key services (education, healthcare, and employment) by walking and cycling [Theme 1, linked to criterion 4 Core Policy 10];

Strong or moderate potential for suitable access to the area from the highway network, minimising the potential for compromising highway network functionality [Theme 2, linked to criterion 3 Core Policy 10]; and

High / medium likelihood that development would offer wider transport and accessibility opportunities to those living in existing communities across Chippenham [Theme 3, linked to criterion 3 Core Policy 10].

2.5. Strategic Areas that sit within Category 2, 3 or 4 demonstrate two out of the three attributes listed above, while those in Category 5, 6 or 7 demonstrate only one. Any Strategic Area that is not considered to demonstrate any of the above three attributes is placed in Category 8.

•Potential strategic area access by public transport, walking and cycling. This theme is linked to criterion 4 of revised Core Policy 10.

Theme 1

•Potential strategic area highway access and network impacts. This theme is linked to criterion 3 of revised Core Policy 10.

Theme 2

•Wider transport opportunities for existing communities. This theme is linked to criterion 3 of revised Core Policy 10.

Theme 3

Page 9: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 9

Figure 2-1 Strategic Area Assessment Themes and Categories

Key Theme 1 – Sustainable Access 2.6. The assessment for Key Theme 1 is based on an initial quantified assessment of the Strategic

Areas under two criteria:

a. Ease of access to key services within Chippenham by non-motorised modes. Maps have been prepared showing the Strategic Areas with distance bandings at 400 metre intervals (5 minutes’ walking time), up to a maximum of 3200 metres (approximately 2 miles, 40 minutes’ walking time) from:

(i) The Town Hall, Chippenham town centre (located to the west of the main retail area). The Town Hall has been selected as a representative point for the town centre and rail station areas, as it is located approximately 400-450 metres south of the rail station and Wiltshire College, and 300 metres north-west of the bus station and the most eastern extent of the main retail area5;

(ii) Secondary schools (Abbeyfield, Hardenhuish, and Sheldon); (iii) Chippenham Community Hospital; and (iv) Principal Employment areas within the Chippenham Community Area (Bumpers

Farm, Methuen Park, Parsonage Way) and employment within the town centre.

Policy link: Criterion 4 revised Core Policy 10

5 At this first (high level) assessment stage, multiple analyses for different locations within the town centre and rail station

areas have not been undertaken. However, any interpretation of the analysis in this Evidence Paper, for Key Theme 1 criteria (a), should bear in mind that Strategic Areas A and B are closer to the rail station and college than the retail area, while Strategic Areas C, D and E are closer to the main retail area.

1

2

3

7

5

6

4

8

Key Theme 2: Potential Strategic Area highway access and

network impacts

Key Theme 3: Wider transport opportunities for existing communities

Key Theme 1: Potential Strategic Area access by public transport, walking and cycling

Page 10: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 10

b. Potential for access by public transport; Key potentially commercially viable public transport corridors adjacent to and within the Strategic Areas have been identified. These corridors broadly follow the main radial routes into Chippenham town centre. Distance bandings at 400 metre intervals from the key corridors have been overlaid onto a Strategic Area map.

Policy link: Criterion 4 revised Core Policy 10

Key Theme 2 – Highway Access 2.7. The assessment for Key Theme 2 is based on an initial quantified assessment of the Strategic

Areas under two specific criteria. The assessments have been mapped, firstly in isolation as separate criteria and then combined as a single map to identify the Strategic Areas, or parts of Strategic Areas, which have the strongest highway access potential and which least compromise the functionality of the wider highway network. The two criteria for Key Theme 2 are:

a. Proximity to forecast congestion hotspots where mitigation is considered to be challenging: Notwithstanding the sustainable transport measures implemented, any significant housing and employment development is likely to place increased pressure on the surrounding road network. For this criterion the focus is on identifying those weak points on the highway network where congestion is most likely to occur under any future growth scenario, and where in-situ mitigation would be challenging due to environmental or other physical constraints. Potential congestion hotspots were identified from new AM and PM peak Chippenham S-Paramics model runs (2026 forecast year), with revised non-allocated Core Strategy housing growth distributed across all of the Strategic Areas in proportion to the area’s size. This ensures that the potential impact from all areas is incorporated into the analysis, while capping the total quantum of development at the revised Core Strategy level.

Policy link: Criterion 3 revised Core Policy 10

b. Potential access from the Primary Route Network (PRN), taking into account the highway infrastructure (new link roads) that could feasibly be delivered to allow efficient access, particularly for goods vehicles accessing potential new employment areas. For this criterion, distance bandings at 500 metre intervals from the PRN (A350) were overlaid onto a Strategic Area map and the percentage of each Strategic Area within each distance banding was calculated.

Policy link: Criterion 3 revised Core Policy 10

Overall Assessment of Key Theme 2 Considering the criteria together, each Strategic Area has been classed as having a relatively ‘Strong’, ‘Moderate’, or ‘Weak’ potential for efficient highway access. Strategic Areas with a ‘Strong’ or ‘Moderate’ potential were then considered as fitting into one of categories 1, 2, 4 or 6 (see Figure 2-1). The category in which a Strategic Area is ultimately placed depends on the assessment outcomes from across Key Themes 1 to 3.

Overall Assessment of Key Theme 1 Considering the criteria together, each Strategic Area has been classed as having a relatively ‘Strong’, ‘Moderate’, or ‘Weak’ potential for efficient access by public transport, walking and cycling. Strategic Areas with a ‘Strong’ or ‘Moderate’ potential were then considered as fitting into one of categories 1, 2, 3 or 5 (see Figure 2-1), with further refinement subject to the outcomes from Key Themes 2 and 3. Strategic Areas considered as having ‘Weak’ potential for easy access by a range of transport modes were considered as fitting into one of categories 4, 6, 7 or 8 (see Figure 2-1), again with further refinement subject to the outcomes from Key Themes 2 and 3.

Page 11: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 11

Key Theme 3 – Wider Transport Opportunities 2.8. The assessment for Key Theme 3 is based on a narrative in response to the following three

transport and accessibility questions:

a. Could development and associated infrastructure at Strategic Area X be potentially beneficial in terms of journey times, reliability and highway network resilience to existing Chippenham residents and businesses?

b. Could development in Strategic Area X potentially provide new attractive walking and cycling links that help to increase the use of these active modes among existing residents?

c. Could development in Strategic Area X lead to improved public transport access for existing Chippenham residents to employment, health, education and retail facilities?

2.9. Where the answers to all three questions are favourable, then the likelihood that development in that Strategic Area would offer wider transport and accessibility opportunities is considered to be ‘High’. Where the answers for two out of the three questions are favourable then the likelihood is considered to be ‘Medium’. Less favourable answers will mean that the Strategic Area is given a ‘Low’ rating for wider transport opportunities.

Policy link: Criterion 3 revised Core Policy 10

Overall Assessment 2.10. The final decision as to which category a Strategic Area is placed depends on the outcomes from

across all three key themes. Further adjustments to the categories are then considered based on Strategic Area interdependencies. This ensures that a Strategic Area which is likely to depend on another Strategic Area to be developed is not placed in a preferential category compared to the area on which it depends.

Overall Assessment of Key Theme 3 Strategic Areas with a ‘High’ or ‘Medium’ likelihood of providing wider transport opportunities for existing communities are considered as fitting into one of categories 1, 3, 4 or 7 (see Figure 2-1).

Page 12: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 12

3. Key Theme 1 – Sustainable Access

Introduction 3.1. This chapter assesses potential Strategic Area access by non-motorised modes and public

transport (referred to in revised Core Policy 10 as ‘alternatives to the private car’). The criteria used are:

3.2. The assessments are firstly presented in isolation as separate criteria and then combined as a single ‘heat’ map to identify the Strategic Areas, or parts of Strategic Areas, that have the strongest access potential by public transport, walking and cycling.

3.3. In order to divide the Strategic Areas into relatively strong, moderate and weak areas, each Strategic Area has been subdivided using distance bands from each of the key services or public transport corridors. The distance bands have then been scored according to each individual criterion before aggregating the scores. The key locations used to create these distance bands are shown in Figure 3-1.

(a) Ease of access to key services within Chippenham by non-motorised modes (walking and cycling)

(b) Potential for access by public transport

Page 13: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 13

Figure 3-1 Locations for Key Theme 1

Page 14: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 14

Ease of Access to Key Services by Non-Motorised Modes 3.4. Access by non-motorised modes (walking and cycling) from each Strategic Area, has been

assessed separately to each of the following key services:

The town centre (Town Hall), located approximately 400-450 metres south of the rail station and Wiltshire College, and 300 metres north-west of the bus station and the most eastern extent of the main retail area6;

Secondary Schools (Abbeyfield, Hardenhuish, Sheldon);

Chippenham Community Hospital; and

Principal employment areas within the Chippenham Community Area, as well as the employment opportunities available in the town centre.

The Town Centre 3.5. The Town Hall was selected as a location to represent the town centre and rail station areas. It is

located close to the main river crossing in the town centre, and is between the rail station / Wiltshire College and the main retail area.

3.6. The Strategic Areas were divided according to their proximity to the Town Hall. 400 metre distance bandings (5 minutes’ walk) from the Town Hall were drawn, and parts of the Strategic Areas were categorised as shown in Table 3-1. This is presented in Figure 3-2, along with the proportion of each Strategic Area in each category (see Table 3-2).

3.7. As the rail station and Wiltshire College are located approximately 400-450 metres north of the Town Hall, it follows that Strategic Areas to the north (A and B) are closer to the rail station than they are to the main retail area. Strategic Areas C, D and E are closer to the main retail area than they are to the rail station. This should be borne in mind when interpreting Figure 3-2 and Table 3-2.

Table 3-1 Access to Town Centre Categorisation

Categorisation Distance Banding

Strong 0m-1600m (up to approximately 1 mile)

Moderate 1600m-2400m (approximately 1 to 1.5 miles)

Weak 2400m-3200m (approximately 1.5 to 2 miles)

6 At this first (high level) assessment stage, multiple analyses for different locations within the town centre and rail station

areas have not been undertaken. However, any interpretation of the analysis in this Evidence Paper, for Key Theme 1 criteria (a), should bear in mind that Strategic Areas A and B are closer to the rail station and college, while Strategic Areas C, D and E are closer to the main retail area.

Page 15: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 15

Figure 3-2 Ease of Access to Town Centre by Non-Motorised Modes Map

Table 3-2 Ease of Access to Town Centre by Non-Motorised Modes Assessment

3.8. With regards to non-motorised access to the town centre, Strategic Areas A and B have the largest proportion classed as strong or moderate (95% and 100% respectively), although due to its large size, Strategic Area C actually provides the most hectares of land classified as strong or moderate; approximately 154 hectares of land are within 1.5 miles of the town centre. It should be noted that Strategic Area B is particularly strong in relation to non-motorised access to the rail station.

Strategic Area Strong Moderate Weak Very Weak

A 3% (3ha) 92% (79ha) 5% (4ha) 0% (0ha)

B 66% (33ha) 34% (17ha) 0% (0ha) 0% (0ha)

C 12% (30ha) 48% (124ha) 36% (92ha) 4% (9ha)

D 2% (5ha) 46% (105ha) 52% (119ha) 0% (0ha)

E 25% (41ha) 43% (71ha) 32% (54ha) 0% (0ha)

Grand Total 14% (111ha) 51% (396ha) 34% (269ha) 1% (9ha)

Page 16: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 16

3.9. Strategic Area D has more than half of its land area classified as weak (52%) in terms of non-motorised access to the town centre, while approximately one third of Strategic Areas C and E is also classified as weak (36% and 32% respectively).

Schools 3.10. Access to education from the Strategic Areas is represented by access to secondary schools in

the area – primary schools are not considered at this high level assessment stage, as a large enough development could potentially include primary school provision. The two college campuses in town are also excluded – the main campus of Wiltshire College is excluded as it is already captured through access to the town centre. Lackham campus is excluded as it is a specialist campus.

3.11. The Strategic Areas were divided according to their proximity to schools. 400 metre distance bandings from the three secondary schools were drawn, and parts of the Strategic Areas were categorised as shown in Table 3-3. This is presented in Figure 3-3, along with the proportion of each Strategic Area in each category (see Table 3-4).

Table 3-3 Access to Secondary Schools Categorisation

Categorisation Distance Banding

Strong 0m-1600m (up to approximately 1 mile)

Moderate 1600m-2400m (approximately 1 to 1.5 miles)

Weak 2400m-3200m (approximately 1.5 to 2 miles)

Page 17: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 17

Figure 3-3 Ease of Access to Secondary Schools by Non-Motorised Modes Map

Table 3-4 Ease of Access to Secondary Schools by Non-Motorised Modes Assessment

Strategic Area Strong Moderate Weak Very Weak

A 66% (56ha) 34% (29ha) 0% (0ha) 0% (0ha)

B 25% (12ha) 75% (38ha) 0% (0ha) 0% (0ha)

C 99% (253ha) 1% (1ha) 0% (0ha) 0% (0ha)

D 45% (104ha) 55% (125ha) 0% (<1ha) 0% (0ha)

E 0% (0ha) 31% (52ha) 63% (104ha) 6% (10ha)

Grand Total 54% (426ha) 31% (245ha) 13% (104ha) 1% (10ha)

3.12. Strategic Areas A, B, C and D all score relatively well for this criterion, with almost 100% of all

four areas classified as either strong or moderate. However, it is clear that Strategic Area C is the strongest, due to its close proximity to Abbeyfield School.

3.13. Strategic Area E performs least well, with only 31% of the Strategic Area having moderate non-motorised access to any of the existing secondary schools in Chippenham.

Page 18: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 18

Hospital 3.14. Access to health services was represented by access to Chippenham Community Hospital – this

is the only NHS hospital in Chippenham, and has a range of general departments including maternity services and a minor injuries unit. GP surgeries or local health centres were not included at this high level assessment stage, as a large enough development could be assumed to include a GP surgery or local health centre.

3.15. The Strategic Areas were divided according to their proximity to Chippenham Community Hospital. 400 metre distance bandings from Chippenham Community Hospital were drawn, and parts of the Strategic Areas were categorised as shown in Table 3-5. This is presented in Figure 3-4, along with the proportion of each Strategic Area in each category (see Table 3-6).

Table 3-5 Access to the Hospital Categorisation

Categorisation Distance Banding

Strong 0m-1600m (up to approximately 1 mile)

Moderate 1600m-2400m (approximately 1 to 1.5 miles)

Weak 2400m-3200m (approximately 1.5 to 2 miles)

Figure 3-4 Ease of Access to the Hospital by Non-Motorised Modes Map

Page 19: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 19

Table 3-6 Ease of Access to the Hospital by Non-Motorised Modes Assessment

Strategic Area Strong Moderate Weak Very Weak

A 0% (0ha) 4% (3ha) 86% (73ha) 10% (9ha)

B 0% (0ha) 38% (19ha) 62% (31ha) 0% (0ha)

C 0% (0ha) 15% (37ha) 49% (126ha) 36% (91ha)

D 12% (27ha) 42% (96ha) 46% (105ha) <1% (2ha)

E 73% (122ha) 27% (44ha) 0% (0ha) 0% (0ha)

Grand Total 19% (149ha) 25% (200ha) 43% (335ha) 13% (102ha)

3.16. Strategic Area E scores well for this criterion, with 100% of the Strategic Area having strong or moderate non-motorised access to Chippenham Community Hospital, although much of the most accessible area encompasses the Rowden Conservation Area.

3.17. Strategic Areas A, B and C all perform relatively poorly, with none having strong non-motorised access to the hospital, and the majority of these areas being classed as weak or very weak. In particular, more than one third of Strategic Area C (36%) is more than 2 miles from the hospital, such that the potential for encouraging non-motorised access is low.

Employment Areas 3.18. Principal Employment Areas were taken from the emerging Core Strategy: Bumpers Farm,

Methuen Park, Parsonage Way, and Langley Park, with the town centre also mapped as an additional employment area. At this high level stage of the analysis, no account has been taken of the type of employment opportunities available at each site and it has been assumed that access to all employment sites is equally beneficial. The different types of current employment are also of less relevance when considering a long term pattern of development.

3.19. The Strategic Areas were divided according to their proximity to the employment areas. 400 metre distance bandings from all of the employment areas were drawn, and parts of the Strategic Areas were categorised as shown in Table 3-7. This is presented in Figure 3-5, along with the proportion of each Strategic Area in each category (see Table 3-8).

Table 3-7 Access to Employment Areas Categorisation

Categorisation Distance Banding

Strong 0m-1600m (up to approximately 1 mile)

Moderate 1600m-2400m (approximately 1 to 1.5 miles)

Weak 2400m-3200m (approximately 1.5 to 2 miles)

Page 20: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 20

Figure 3-5 Ease of Access to Employment Areas by Non-Motorised Modes Map

Table 3-8 Ease of Access to Employment Areas by Non-Motorised Modes Assessment

Strategic Area Strong Moderate Weak Very Weak

A 100% (85ha) 0% (0ha) 0% (0ha) 0% (0ha)

B 100% (50ha) 0% (0ha) 0% (0ha) 0% (0ha)

C 39% (101ha) 41% (104ha) 20% (50ha) 0% (0ha)

D 10% (24ha) 65% (150ha) 25% (56ha) 0% (0ha)

E 92% (152ha) 8% (14ha) 0% (0ha) 0% (0ha)

Grand Total 52% (412ha) 34% (268ha) 14% (106ha) 0% (0ha)

3.20. Strategic Areas A and B perform particularly well for this criterion, with 100% of both areas

classed as having strong non-motorised access to principal employment areas or the employment opportunities within the town centre. Strategic Area E also performs well, with 100% classed as having strong or moderate access, primarily due to its close proximity to both Methuen Park (a principal employment area adjacent to the A350/A4 junction) and the town centre.

3.21. Strategic Areas C and D perform less well in percentage terms, with 20% and 25% of land respectively being classed as weak. However, both areas have approximately 175-200 hectares classed as strong or moderate. In terms of actual land area, Strategic Area C has the greatest classed as strong or moderate.

Page 21: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 21

Potential for Access by Public Transport 3.22. Key potentially commercially viable public transport corridors adjacent to and within the Strategic

Areas have been identified (see Figure 3-1). All corridors serve Chippenham town centre and, where realistic, the public transport corridors also serve key education and health services, employment and retail opportunities. Corridors were initially based on existing bus routes, and then expanded to include radial routes that would connect Chippenham town centre to other trip attractors / generators (for example, surrounding towns and cities). Orbital type routes, or routes that ‘loop’ around Strategic Areas are not included as they are generally more difficult for operators to provide without subsidy. Services which require a subsidy are not considered to be sustainable in the long term.

3.23. The Strategic Areas have been assessed according to their access to the public transport corridors by active modes, with a focus on walking as a more common mode used to access bus stops. Due to the fact that walking to the public transport corridor will be only the first stage of a multi-stage journey, shorter distance bandings have been used than for other sustainable access criteria. 400 metre distance bandings from all of the public transport corridors were drawn, and parts of the Strategic Areas were categorised as shown in Table 3-9. This is presented in Figure 3-6, along with the proportion of each Strategic Area in each category (see Table 3-10).

Table 3-9 Proximity to Public Transport Corridors Categorisation

Categorisation Distance Banding

Strong 0m-400m (approximately ¼ mile or 5 minutes’ walk)

Moderate 400m-1200m (up to approximately ¾ mile or 15 minutes’ walk)

Weak 1200m-1600m (up to approximately 1 mile or 20 minutes’ walk)

Page 22: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 22

Figure 3-6 Potential for Access by Public Transport Map

Table 3-10 Potential for Access by Public Transport Assessment

Strategic Area Strong Moderate Weak Very Weak

A 61% (52ha) 39% (33ha) 0% (0ha) 0% (0ha)

B 0% (0ha) 100% (50ha) 0% (0ha) 0% (0ha)

C 15% (39ha) 55% (140ha) 26% (67ha) 4% (9ha)

D 13% (30ha) 45% (104ha) 34% (78ha) 8% (18ha)

E 66% (110ha) 34% (56ha) 0% (0ha) 0% (0ha)

Grand Total 29% (232ha) 49% (383ha) 18% (145ha) 4% (27ha)

3.24. Strategic Areas A, B and E perform best for this criterion, with 100% of all three areas classed as having relatively strong or moderate access to public transport corridors.

3.25. Strategic Areas C and D perform less well in percentage terms, with both areas having land classed as outside of reasonable access to commercially viable public transport corridors. Area D in particular has the greatest amount of land (in proportional and absolute terms) classed as weak or very weak (42% or 96 hectares). Although Strategic Areas C and D have areas of land alongside the A4 corridor which are classed as strong for public transport access, bespoke subsidised services may be required to serve the other parts of those Strategic Areas that are beyond a reasonable walking distance from the A4 / London Road.

Page 23: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 23

Overall Assessment for Key Theme 1 3.26. In order to develop an overall categorisation of the Strategic Areas, scores were awarded for

each individual criterion (3 for strong, 2 for moderate and 1 for weak), and these scores were summed across the five sub-criteria to give a potential range of scores from 0 to 15. No part of any Strategic Areas scored below 3 and the vast majority of land scored between 7 and 15.

3.27. The summed scores have been used to create the aggregated heat map for sustainable access shown in Figure 3-7, and the overall proportions of each Strategic Area classed as strong, moderate or weak in Table 3-11. Parts of Strategic Areas scoring 11-15 in total are classed as ‘strong’, areas scoring 6-10 are classed as ‘moderate’, and areas scoring 5 or less are classed as ‘weak’. Strategic Areas with a high proportion of relatively strong or moderate areas are considered as fitting into one of categories 1, 2, 3 or 5 (see Figure 2-1 for categories).

3.28. An alternative approach to aggregating the scores for the individual criterion is also presented in Table 3-12. The summed scores have been ranked, with the top third classed as relatively strong, the middle third moderate, and the bottom third relatively weak. This method allows for a more even distribution across the ‘strong’, ‘moderate’ and ‘weak’ categories (approximately a third of total Strategic Area land is within each category) and therefore allows for the comparative performance of areas of land to be more easily distinguished.

Figure 3-7 Key Theme 1 Heat Map – Sustainable Access

Page 24: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 24

3.29. As can be seen in Figure 3-7 and Table 3-11, Strategic Area A has the highest proportion of land classified as strong (87%) in terms of sustainable access (by modes other than the private car). Although due to its large size, Area E has the greatest land area classed as strong (approximately 122 hectares).

3.30. Strategic Area D has the greatest proportion of land area (5%) classed as ‘weak’. However, there are few areas of land classified as ‘weak’ across the sustainable access sub-categories, making it difficult to compare the relative performance of each Strategic Area. For this reason, it is useful to review the comparative assessment presented in Table 3-12, which directly compares the areas against each other and places approximately one third of all Strategic Area land within each of the ‘strong’, ‘moderate’ and ‘weak’ categories.

3.31. Assessing the comparative performance of the Strategic Areas (Table 3-12) then Strategic Area B performs well in terms of the percentage of land having a strong sustainable access potential (46%), with Area E continuing to have the greatest land area classed as strong (approximately 96 hectares). In comparative terms, Strategic Areas C and D perform least well and have the highest proportion of land classified as relatively weak (44% and 59% respectively).

3.32. The final two (right hand) columns in Table 3-11 and Table 3-12 indicate whether a considerable portion7 of the Strategic Area demonstrates the following transport and accessibility attribute:

Strong or moderate potential for easy access to the area from public transport networks, and to/from Chippenham town centre (rail station, college and retail) and key services (education, healthcare, and employment) by walking and cycling [linked to criterion 4, Core Policy 10].

Table 3-11 Overall Assessment for Key Theme 1 – Absolute Scores

Strategic Area

Strong (score 11-15)

Moderate (score 6-10)

Weak (score 0-5)

Relatively Strong or Moderate Sustainable Access?

Potential Categories (Venn Diagram Figure 2-1)

A 87% (74ha) 13% (11ha) 0% (0ha) 1,2,3,5

B 68% (34ha) 32% (16ha) 0% (0ha) 1,2,3,5

C 29% (75ha) 70% (179ha) 1% (1ha) 1,2,3,5

D 27% (63ha) 68% (156ha) 5% (11ha) 1,2,3,5

E 73% (122ha) 27% (44ha) 0% (0ha) 1,2,3,5

Grand Total 47% (368ha) 52% (406ha) 1% (12ha)

Table 3-12 Overall Assessment for Key Theme 1 – Comparative Performance

Strategic Area

Strong (compared to

other Strategic Areas)

Moderate (compared to

other Strategic Areas)

Weak (compared to

other Strategic Areas)

Relatively Strong or Moderate Sustainable Access?

Potential Categories (Venn Diagram Figure 2-1)

A 32% (28ha) 63% (53ha) 5% (4ha) 1,2,3,5

B 46% (23ha) 54% (27ha) 0% (0ha) 1,2,3,5

C 16% (42ha) 40% (102ha) 44% (111ha) X 4,6,7,8

D 9% (21ha) 32% (73ha) 59% (136ha) X 4,6,7,8

E 58% (96ha) 26% (44ha) 16% (26ha) 1,2,3,5

Grand Total 27% (210ha) 38% (299ha) 35% (277ha)

7 For the purpose of this analysis, Strategic Areas with more than 10% of the area classed as strong, and more than two-

thirds classed as either strong or moderate are considered to demonstrate this attribute.

Page 25: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 25

3.33. The differences between Strategic Area characteristics, in relation to sustainable access, cannot be as clearly distinguished with the first method of summing the scores (Table 3-11). A straightforward summation of sub-criteria scores has masked the differences that exist.

3.34. The comparative performance (Table 3-12) uncovers the differences and therefore it is the result of this comparative assessment that will be used in this Evidence Paper as the outputs from Key Theme 1.

3.35. The assessment for Key Theme 1 identifies the relative differences between areas of land surrounding Chippenham. As there is no universally agreed approach to this type of high level assessment, and given that the assessment is based on relative differences, the assessment outputs cannot be compared to locations elsewhere.

Page 26: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 26

4. Key Theme 2 – Highway Access

Introduction 4.1. The criteria used to assess potential Strategic Area highway access and network impacts are:

Network Impacts 4.2. This criterion assesses the proximity of Strategic Areas to forecast congestion hotspots (weak

points on the highway network) where physical mitigation is considered to be challenging.

4.3. Notwithstanding any sustainable transport measures implemented, significant housing and employment development will almost certainly place increased pressure on the immediately adjacent road network. For this criterion the focus is on identifying those weak points on the highway network where congestion is most likely to occur under any future growth scenario, and where in-situ mitigation would be unrealistic due to environmental or other physical constraints8. The analysis includes the road network within and immediately adjacent to the Chippenham urban area, from the M4 corridor in the north to Lackham and Pewsham in the south.

4.4. Potential congestion hotspots (weak points on the highway network) have been identified from new AM and PM peak Chippenham S-Paramics model runs. The model runs use a 2026 forecast year with revised non-allocated Core Strategy housing growth distributed across Strategic Areas A-E in proportion to each area’s size. This ensures that the potential impact from all areas is incorporated into the analysis, while capping the total quantum of development at the revised Core Strategy level. While the potential impact of new link roads around Chippenham is referred to in the overall analysis, the new model runs do not specifically include these new roads as they would be likely to mask a number of potentially weak points on the highway network.

4.5. Congestion hotspots have been identified from the model runs with respect to ‘time spent queuing’9 and then assessed for the physical ‘ease of mitigation’ in-situ. Ease of mitigation has been assessed using an environmental constraints map10 and a desktop review of the surrounding urban form to identify buildings or other urban features that could constrain mitigation. Upon review of the modelling results, it has become apparent that many of the congestion hotspots are closely linked, focused particularly on the radial routes into the town centre, such that it has been more appropriate to identify the most congested corridors.

4.6. Congested corridors, which also have environmental or other constraints potentially reducing the physical mitigation options available, have been mapped (see Figure 4-1). 500 metre distance bands have been used to categorise the Strategic Areas, as shown in Table 4-1. Strategic Areas that are within 500 metres of these weak points on the highway network are classified as ‘very weak’ in terms of their highway network impacts, as development in these locations would increase the probability that overall highway network efficiency would be compromised. Areas further from the congested corridors are deemed to be generally more favourable for their

8 Environmental constraints might relate to the presence of woodland or watercourses immediately adjacent to the

highway, while physical constraints might include buildings with frontages that are right up against the highway boundary. 9 For this analysis, junctions are considered to be ‘congested’ when average delays per vehicle exceed one minute.

Where traffic queues from a congested junction then block back across upstream junctions, the entire section of road between junctions is considered to be a ‘congested corridor’. 10 An environmental constraints map has been used to identify specific site designations that could prevent physical

mitigation measures being implemented.

(a) Proximity to forecast congestion hotspots where mitigation is considered to be challenging (network impacts)

(b) Potential access from the Primary Route Network (PRN), taking account of the highway infrastructure that could feasibly be delivered to allow efficient access.

Page 27: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 27

network impacts, as they are generally likely to place lower (or less intense) demands on those particularly congested sections of road11.

4.7. For the purpose of identifying weak points on the highway network, additional mitigation measures, other than highway schemes which are more than likely to be implemented12, have not been included specifically in the S-Paramics model runs. However, a potential new eastern link road through Strategic Areas A, B and C, and a potential southern link road through Strategic Areas D and E have been taken into account when assessing overall network impacts (see Figure 4-3 for potential link road locations). This ensures that the assessment takes account of the possible ways in which transport infrastructure could be developed within the Strategic Areas.

4.8. The assumed existence of link roads for the overall analysis also explains why development in the more peripheral parts of the Strategic Areas is considered, in this part of the assessment, to be less likely to compromise the efficiency of the existing highway network. Traffic generated by, or attracted to, the more peripheral areas will have a greater tendency to use the link roads, thereby avoiding the congested corridors identified in Figure 4-1.

4.9. The percentage of each Strategic Area in each category has been calculated and is shown in Table 4-2 and mapped in Figure 4-2.

Figure 4-1 Congested Corridors with Constraints Limiting Mitigation

11 It is acknowledged that other forms of transport mitigation which encourage mode shift could be considered. However,

as these forms of mitigation have not yet been identified and are likely to be development specific, it is not considered appropriate to make assumptions on these in this high level assessment of transport and accessibility characteristics. 12 The highway schemes included in the modelled scenario are: A350 north of Chippenham pinch-point dualling;

enlarged Malmesbury Road Roundabout with new eastern arm providing access into the North Chippenham development site; and the A350 Chippenham Bypass Improvement scheme being promoted through the Swindon & Wiltshire Local Transport Body.

Page 28: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 28

Table 4-1 Network Impacts Categorisation

Categorisation Distance from the most congested corridors13

Strong 1500m+

Moderate 1000m-1500m

Weak 500m-1000m

Very weak 0m-500m

Figure 4-2 Network Impacts Map

13 1000 metres has been selected as the upper boundary for ‘weak’ as traffic generated by, or attracted to, developments

that are located more than 1000 metres from the congested corridors is, on balance, more likely to route via new link roads rather than through the town centre.

Page 29: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 29

Table 4-2 Network Impacts Assessment

Strategic Area Strong Moderate Weak Very Weak

A 0% (0ha) 41% (35ha) 58% (49ha) 1% (1ha)

B 0% (0ha) 56% (28ha) 44% (22ha) 0% (0ha)

C 59% (150ha) 26% (65ha) 14% (36ha) 1% (3ha)

D 26% (60ha) 47% (108ha) 21% (48ha) 6% (13ha)

E 20% (33ha) 34% (56ha) 31% (52ha) 15% (25ha)

Grand Total 31% (243ha) 37% (293ha) 27% (208ha) 5% (42ha)

4.10. Strategic Area C performs particularly well with regard to potential highway network impacts, with 85% of the Strategic Area being classed as either strong or moderate. However, it should be noted that development in the more peripheral parts of Strategic Area C, and the associated introduction of an eastern link road to divert traffic away from the most congested corridors, would be heavily dependent on development at Strategic Areas A and B. Strategic Areas A and B perform less well in this assessment (only 41% and 56% classed as moderate respectively) because of their proximity to congested corridors to the north of the town centre.

4.11. Strategic Areas D and E contain areas that are close to congested corridors (6% and 15% of land area classed as very weak in terms of highway network impacts).

4.12. The parts of Strategic Areas that are considered to least compromise the functionality of the existing highway network within Chippenham are those on the periphery, which are likely to be closer to new link roads through the Strategic Areas. Development closer to the town centre’s congested corridors would put greater pressure on the existing highway network. This is all dependent on suitable link road provision to access the peripheral areas from the A350.

4.13. In the absence of new link roads Strategic Areas C and D would need to be reassessed, as traffic from these areas would then place significant pressure on the A4 corridor from Pewsham and through the town centre. Development interdependencies are covered further in Chapter 7. Further, more detailed, scenario testing would also be necessary to assess the impacts on the network if growth is to take place before new link roads have been completed.

Potential Access from the Primary Route Network 4.14. This criterion assesses potential access from the Primary Route Network (PRN), taking account

of the highway infrastructure that could feasibly be delivered to allow efficient access, particularly for goods vehicles accessing potential new employment areas.

4.15. A key assumption for this criterion is the existence of suitable link roads through the Strategic Areas from the A350 at Malmesbury Road and the A350 at Lackham, including a northern / eastern link road connecting Strategic Areas A, B and C or a southern link road connecting Strategic Areas D and E, as shown in Figure 4-3.

Page 30: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 30

Figure 4-3 Potential Link Roads Providing Access from the PRN

4.16. To categorise areas as ‘strong’, ‘moderate’ or ‘weak’, both the distance from the A350 along the assumed link roads and the distances from those link roads were taken into account. It was assumed that distance travelled away from the link road is more of a deterrent than distance travelled along the link road, and so distances of up to 2000m were considered along the link road compared to a maximum of 500m away from the link road. This means that parts of Strategic Areas which would be nearer to a link road perform more strongly. The distances were summed to give an overall distance travelled from the A350 and categorised according to Table 4-3. The percentage of each Strategic Area in each category was calculated and is shown in Table 4-4 alongside the equivalent land area (hectares), and this is also mapped in Figure 4-4.

Table 4-3 PRN Access Categorisation

Categorisation Total distance from PRN

Strong 0m-1000m

Moderate 1000m-2000m

Weak 2000m-2500m

Very weak 2500m+

4.17. Strategic Areas A and E perform best in this assessment with 94% (80ha) and 71% (119ha) respectively being classified as either strong or moderate. Strategic Area C performs least well

Page 31: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 31

with 100% of its area being classed as very weak. Strategic Area D has large areas classed as weak or very weak.

Figure 4-4 Access to the PRN Map

Table 4-4 Potential Access from the PRN Assessment

Strategic Area Strong Moderate Weak Very Weak

A 26% (22ha) 68% (58ha) 0% (0ha) 6% (5ha)

B 0% (0ha) 0% (0ha) 33% (17ha) 67% (33ha)

C 0% (0ha) 0% (0ha) 0% (0ha) 100% (255ha)

D 0% (0ha) 24% (55ha) 10% (24ha) 66% (151ha)

E 44% (73ha) 27% (46ha) 4% (7ha) 25% (41ha)

Grand Total 12% (94ha) 20% (159ha) 6% (48ha) 62% (485ha)

Page 32: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 32

Overall Assessment for Key Theme 2 4.18. In order to develop an overall categorisation of the Strategic Areas, scores were awarded for

each individual criterion (3 for strong, 2 for moderate and 1 for weak), and the scores for the two sub-criteria were summed to give a potential maximum score of 6.

4.19. The summed scores have been used to create the aggregated heat map for highway access shown in Figure 4-5, and the overall proportions of each Strategic Area classed as strong, moderate or weak in Table 4-5. Parts of Strategic Areas scoring 5 or 6 in total are classed as ‘strong’, areas scoring 3 or 4 are classed as ‘moderate’, and areas scoring less than 3 are classed as ‘weak’. Strategic Areas with a high proportion of relatively strong or moderate areas are considered as fitting into one of categories 1, 2, 4 or 6 (see Figure 2-1 for categories).

4.20. An alternative approach to aggregating the scores for the individual criterion is also presented in Table 4-6. The summed scores have been ranked, with the top third of scores classed as relatively strong, the middle third moderate, and the bottom third relatively weak. This method can allow for a more even distribution across the ‘strong’, ‘moderate’ and ‘weak’ categories (as with Key Theme 1) and can allow for the comparative performance of areas of land to be more easily distinguished. However, as the range of possible scores is lower for Key Theme 2, and there are a greater number of areas with the same score, this comparative method is not particularly effective in creating a more even distribution across the categories.

Figure 4-5 Key Theme 2 Heat Map – Highway Access and Impacts

Page 33: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 33

4.21. Reviewing Figure 4-5 and Table 4-5, Areas A and E provide the largest amount of land classed as strong (15%/13ha and 44%/73ha respectively) in terms of overall highway access and network impacts. In other words, both have areas of land that can be easily accessed from the PRN and which, if developed, are least likely to compromise the efficiency of Chippenham’s existing highway network.

4.22. While Area E has the largest area of land, in both percentage and absolute terms, which is assessed as ‘strong’, Area E also has the largest area of land (19ha) assessed as ‘very weak’ for overall highway access and network impacts. The most northerly part of Area E is close to the most congested sections of the A4 Bath Road and A4 Avenue La Fleche corridors (as they approach The Bridge Centre), and is also approximately 2km from the nearest point on the PRN.

4.23. Areas B, C and D do not perform quite as well in terms of highway access and network impacts as they all have areas in close proximity to the town centre’s most congested corridors, as well as being located some distance from the nearest point on the PRN.

4.24. Assessing the comparative performance of the Strategic Areas (Table 4-6), then Areas A and E again perform well in percentage terms (93% and 70% respectively assessed as ‘strong’) for overall highway access and network impacts. However, in purely comparative terms, Area C is shown to provide the largest area of land classed as ‘strong’ (approximately 150 hectares).

4.25. The final two (right hand) columns in Table 4-5 and Table 4-6 indicate whether a considerable portion14 of the Strategic Area demonstrates the following transport and accessibility attribute:

Strong or moderate potential for suitable access to the area from the highway network, minimising the potential for compromising highway network functionality [linked to criterion 3, Core Policy 10].

Table 4-5 Overall Assessment of Key Theme 2 – Absolute Scores

Strategic Area

Strong (score 5-6)

Moderate (score 3-4)

Weak (score 1-2)

Very Weak (score 0)

Relatively Strong or Moderate Highway Access / Impacts?

Potential Categories (Venn Diagram Figure 2-1)

A 15% (13ha) 78% (67ha) 7% (6ha) 0% (0ha) 1,2,4,6

B 0% (0ha) 12% (6ha) 88% (44ha) 0% (0ha) X 3,5,7,8

C 0% (0ha) 59% (150ha) 40% (101ha) 1% (3ha) X 3,5,7,8

D 0% (0ha) 49% (113ha) 51% (117ha) 0% (0ha) X 3,5,7,8

E 44% (73ha) 26% (43ha) 19% (31ha) 11% (19ha) 1,2,4,6

Grand Total 11% (85ha) 48% (379ha) 38% (299ha) 3% (23ha)

Table 4-6 Overall Assessment of Key Theme 2 – Comparative Performance

Strategic Area

Strong (compared to

other Strategic Areas)

Moderate (compared to

other Strategic Areas)

Weak (compared to

other Strategic Areas)

Very Weak (compared to

other Strategic Areas)

Relatively Strong or Moderate Highway Access / Impacts?

Potential Categories (Venn Diagram Figure 2-1)

A 93% (79ha) 7% (6ha) 0% (0ha) 0% (0ha) 1,2,4,6

B 12% (6ha) 64% (32ha) 24% (12ha) 0% (0ha) 1,2,4,6

C 59% (150ha) 26% (65ha) 14% (36ha) 1% (3ha) 1,2,4,6

D 49% (113ha) 46% (105ha) 5% (12ha) 0% (0ha) 1,2,4,6

E 70% (116ha) 5% (8ha) 14% (23ha) 11% (19ha) 1,2,4,6

Grand Total 59% (464ha) 28% (216ha) 11% (83ha) 3% (23ha)

14 For the purpose of this analysis, Strategic Areas with more than 10% of the area classed as strong, and more than

two-thirds classed as either strong or moderate are considered to demonstrate this attribute.

Page 34: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 34

4.26. Table 4-5 and Table 4-6 show the outcome of the two alternative methods for combining the scores from the Key Theme 2 sub-criteria. Two of the five Strategic Areas (A and E, see Table 4-7) have been assessed as demonstrating strong or moderate highway access and network impact attributes through both methods. Strategic Areas A and E are therefore considered as more likely to have suitable access from the PRN and to minimise the potential for compromising highway network functionality.

Table 4-7 Overall Assessment of Key Theme 2

Strategic Area

Absolute Score Assessment (from Table 4-5)

Comparative Performance Assessment (from Table 4-6)

Relatively Strong or Moderate, using both methods?

Potential Categories (Venn Diagram Figure 2-1)

A 1,2,4,6

B X X 3,5,7,8

C X X 3,5,7,8

D X X 3,5,7,8

E 1,2,4,6

4.27. The assessment for Key Theme 2 identifies the relative differences between areas of land surrounding Chippenham. As there is no universally agreed approach to this type of high level assessment, and given that the assessment is based on relative differences, the assessment outputs cannot be compared to locations elsewhere.

Page 35: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 35

5. Key Theme 3 – Wider Transport Opportunities

Introduction 5.1. The assessment for Key Theme 3, which is based on criterion 3 of revised Core Policy 10, is

based on qualitative responses to three transport and accessibility questions. The questions are designed to highlight the impacts that development within each Strategic Area could have, in transport and accessibility terms, on existing communities. The three questions are:

5.2. Where the answers to all three questions are favourable, then the likelihood that development in that Strategic Area would offer wider transport and accessibility opportunities is considered to be ‘High’. Where the answers for two out of the three questions are favourable then the likelihood is considered to be ‘Medium’. Less favourable answers will mean that the Strategic Area is given a ‘Low’ rating for wider transport opportunities.

5.3. Strategic Areas with a ‘High’ or ‘Medium’ likelihood of providing wider transport opportunities for existing communities are considered as fitting into one of categories 1, 3, 4 or 7 (see Figure 2-1). The final decision as to which category a Strategic Area is placed will depend on the outcomes from across all three key themes.

5.4. A summary assessment for Key Theme 3 is presented in Table 5-1. Strategic Area locations are shown in Figure 1-2.

(a) Highway network resilience

Could development and associated infrastructure at Strategic Area X be potentially beneficial in terms of journey times, reliability and highway network resilience to existing Chippenham residents and businesses?

(b) Non-motorised modes of travel

Could development in Strategic Area X potentially provide new attractive walking and cycling links that help to increase the use of these active modes among existing residents?

(c) Public transport accessibility

Could development in Strategic Area X lead to improved public transport access for existing Chippenham residents, to employment, health, education and retail facilities?

Page 36: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 36

Key Theme 3 Qualitative Assessment

(a) Highway Network Resilience 5.5. Development within any of the five Strategic Areas will almost certainly generate additional trips

by private car and will therefore place increased pressure on the existing highway network. However, providing that suitable highway infrastructure is delivered alongside the new development, there are potential benefits for residents and businesses within existing communities across Chippenham.

5.6. Potential highway infrastructure measures could include an eastern link road through Strategic Areas A, B and C, and/or a southern link road through Strategic Areas D and E (Figure 4-3). An eastern link road through Strategic Areas A, B and C could connect the A4 at Pewsham with the A350 at Malmesbury Road, providing reduced journey times and improved journey time reliability for the existing residents and businesses within Pewsham.

5.7. A southern link road through Strategic Areas D and E could connect the A4 at Pewsham with the A350 at Lackham, again providing reduced journey times and improved journey time reliability for the existing residents and businesses within Pewsham.

5.8. An eastern or southern link road would also provide an opportunity to reduce traffic flows through Chippenham town centre, as a proportion of the traffic between the A4 London Road (Calne and Devizes direction) and the A350 could be re-routed via either link road. Reduced through-traffic flows in Chippenham town centre could be a beneficial impact for many people, particularly residents living within the town centre and along the main radial corridors.

5.9. The assessment presented in Table 5-1 for question (a) reflects the potential that all of the five Strategic Areas have in delivering new highway infrastructure, which could improve journey times, journey time reliability, and reduce traffic flows through Chippenham town centre.

(b) Non-Motorised Modes of Travel 5.10. In order for new developments to be able to provide new attractive walking and cycling links for

existing residents, those developments would need to be located between existing trip generators (primarily existing residential areas) and existing or new trip attractors (such as education, health, and retail services, and employment opportunities).

5.11. The opportunity for development within Strategic Areas A, D and E to deliver new attractive walking and cycling links, which are of use to existing communities, may be limited. This is because existing trip generators and trip attractors are primarily located to one side of each Strategic Area; to the south and south-west of Strategic Area A, to the north of Strategic Area D, and primarily to the north of Strategic Area E. However, limited opportunities may exist to increase walking and cycling among existing Chippenham residents if the Strategic Areas can sustain new services to which residents could walk or cycle.

5.12. Strategic Area B is likely to provide some potential for providing new attractive walking and cycling links that are of use to existing communities, as the southern part of the Strategic Area is located between Monkton Park (residential, employment and education) and Langley Park / Parsonage Way (residential and employment).

5.13. Strategic Area C is likely to present the greatest potential for providing new walking and cycling links that are of use to existing communities, as there are existing trip attractors and generators either side of the Strategic Area that are currently not well connected. Potential exists to increase walking and cycling trips between the Monkton Park / Langley Park / Parsonage Way area (residential, employment and education) and the north-eastern part of Pewsham (residential and secondary education) via Strategic Area C.

Page 37: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 37

(c) Public Transport Accessibility 5.14. In order for new developments to lead to improved public transport accessibility for existing

Chippenham residents, they ideally need to be located along a potentially viable public transport corridor, either immediately upstream or downstream of existing residential areas. Existing residents would then be able to benefit from new services or increased service frequencies that result from having increased public transport demand along a corridor. Potentially commercially viable public transport corridors are presented in Figure 3-1.

5.15. The ability for development within Strategic Areas C and D to lead to improved public transport accessibility for existing residents is likely to be limited, as the majority of both of these areas would probably need to be served by development specific or ‘orbital’15 type services. Typically, it is these types of services that require ongoing subsidy in order for them to be sustained. The medium to long term potential for public transport services in Strategic Areas C and D is therefore questionable.

5.16. Strategic Area B may provide some potential for improving public transport accessibility for existing residents, as it is located in close proximity to the B4069 corridor between Chippenham town centre and Lyneham / Royal Wootton Bassett / Swindon. This is not currently a key bus corridor, although as developments increase in both Chippenham and Swindon, so the potential to use this corridor for bus services may increase. Development within Strategic Area B might also improve the viability of the town bus service which serves Monkton Park, as a relatively short extension to this service would also allow it to serve the potential demand at Strategic Area B.

5.17. Similarly, Strategic Area A may provide some potential for improving public transport accessibility for existing residents. The western side is located adjacent to the B4158 Malmesbury Road corridor, between Chippenham town centre and Malmesbury / Cirencester. The Malmesbury Road corridor is currently used by some fairly low frequency bus services between Chippenham and Malmesbury, the viability of which might be improved slightly by increased demand from Strategic Area A. The eastern side of Strategic Area A is located adjacent to the B4069 corridor (referred to in paragraph 5.16).

5.18. Strategic Area E is likely to present the greatest potential for improving public transport accessibility for existing residents, as it is located directly on the B4528/B4643 corridor, and in close proximity to the A4 Bath Road / Rowden Hill corridor. A number of bus services currently operate along these corridors, connecting Chippenham with Bath, Melksham and Trowbridge, at hourly or half-hourly headways throughout the day. Significant levels of development at Strategic Area E will almost certainly increase the demand for these bus services, potentially improving their commercial viability and allowing for increased service frequencies and extended operating hours. This could improve public transport accessibility to employment areas, as well as to key education, health and retail services, for existing residents across the south-western part of Chippenham.

Key Theme 3 Summary 5.19. Development in the majority of the Strategic Areas has some potential to provide beneficial

transport and accessibility impacts for existing residents and businesses within Chippenham. In particular, Strategic Area C has a high potential to provide new attractive walking and cycling links that will be of use to existing residents, and Strategic Area E has a high potential to assist in improving public transport accessibility.

5.20. Considering the three questions together (Table 5-1) there appears to be little difference between the overall opportunities presented by the Strategic Areas. The exception appears to be for Strategic Area D where potential benefits for existing communities are considered to be more limited than for the other areas.

15 In this Evidence Paper ‘orbital’ services refers to bus services that travel around the periphery of an urban area,

rather than along the radial corridors into the town centre.

Page 38: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 38

Table 5-1 Overall Assessment of Key Theme 3

Question Topic A B C D E

(a) Highway network resilience:

Could development and associated infrastructure at Strategic Area X be potentially beneficial in terms of journey times, reliability and highway network resilience to existing Chippenham residents and businesses?

(b) Non-motorised modes of travel:

Could development in Strategic Area X potentially provide new attractive walking and cycling links that help to increase the use of these active modes among existing residents?

Ξ Ξ Ξ

(c) Public transport accessibility:

Could development in Strategic Area X lead to improved public transport access for existing Chippenham residents, to employment, health, education and retail facilities?

Ξ Ξ

Overall Assessment (High, Medium or Low) Medium High Medium Low Medium

Potential Categories (Venn Diagram Figure 2-1) 1,3,4,7 1,3,4,7 1,3,4,7 2,5,6,8 1,3,4,7

Key:

High potential for existing communities to benefit from development in this Strategic Area

Some potential for existing communities to benefit from development in this Strategic Area

Ξ Benefits to existing communities are uncertain, without development being brought forward in other areas.

Page 39: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 39

6. Key Themes 1-3 Overall Assessment

6.1. The assessments of each Strategic Area under each of the three key themes is summarised in Table 6-1 and presented in the form of a Venn diagram in Figure 6-1.

6.2. The assessment presented in this chapter is a simplified overview of the many assessments in this Evidence Paper. As such this chapter should not be read in isolation. Strategic Areas that are assessed as demonstrating favourable transport and accessibility attributes overall will still have some weaknesses. Similarly, Strategic Areas that are assessed as weaker overall will still have strengths. Specific details on these comparative strengths and weaknesses are contained throughout the Evidence Paper.

6.3. The assessment presented here also generalises for entire Strategic Areas, rather than identifying parts of individual Strategic Areas which may demonstrate more favourable transport and accessibility attributes than other parts of the same Strategic Area. Information on stronger parts of Strategic Areas is provided throughout the Evidence Paper.

6.4. Strategic Areas A and E perform well across all three key themes, demonstrating the following favourable transport and accessibility attributes:

Strong or moderate potential for easy access to the area from public transport networks, and to/from Chippenham town centre (rail station, college and retail) and key services (education, healthcare, and employment) by walking and cycling [Theme 1, linked to criterion 4 Core Policy 10];

Strong or moderate potential for suitable access to the area from the highway network, minimising the potential for compromising highway network functionality [Theme 2, linked to criterion 3 Core Policy 10]; and

High / medium likelihood that development would offer wider transport and accessibility opportunities to those living in existing communities across Chippenham [Theme 3, linked to criterion 3 Core Policy 10].

6.5. Strategic Area B demonstrates two of the transport and accessibility attributes above, with strengths in relation to sustainable access and the wider transport and accessibility opportunities that could be offered to those living in existing communities across Chippenham. However, weaknesses have been noted in relation to highway access and the impact development in this location might have on the existing highway network.

6.6. Strategic Area C has the potential to offer wider transport and accessibility opportunities to those living in existing communities (one of the attributes listed above), although weaknesses have been noted in relation to sustainable access and highway access (the other two attributes).

6.7. Strategic Area D has been assessed as having a number of weaknesses and, at this stage, it cannot be said to demonstrate any of the three transport and accessibility attributes listed above.

6.8. The summary in this chapter relates to the performance of Strategic Areas compared to each other. However, it must be acknowledged that some dependencies exist between the Strategic Areas. In particular, development in one Strategic Area may be partially or fully dependent on development taking place in another Strategic Area, relying on transport infrastructure to be provided to allow for suitable access. Further detail on interdependencies is provided in Chapter 7.

Page 40: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 40

Table 6-1 Summary of Assessments

Strategic

Area

Assessment and Potential Location on Venn Diagram

Location on Venn Diagram16

Key Theme 1 – Sustainable Access

(from Table 3-12)

Key Theme 2 – Highway Access

(from Table 4-7)

Key Theme 3 – Wider Transport Opportunities

(from Table 5-1)

A Strong / Moderate

1 2 3 5

Strong / Moderate

1 2 4 6

High / Medium

1 3 4 7 1

B Strong / Moderate

1 2 3 5

Weak

3 5 7 8

High / Medium

1 3 4 7 3

C Weak

4 6 7 8

Weak

3 5 7 8

High / Medium

1 3 4 7 7

D Weak

4 6 7 8

Weak

3 5 7 8

Low

2 5 6 8 8

E Strong / Moderate

1 2 3 5

Strong / Moderate

1 2 4 6

High / Medium

1 3 4 7 1

Figure 6-1 Strategic Area Assessment – Venn Diagram

16 The Venn diagram location for a Strategic Area is taken to be the potential location (1-8) that appears under each of

the key themes for that Strategic Area.

1

2

3

7

5

6

4

8

Key Theme 2: Potential Strategic Area highway access and

network impacts

Key Theme 3: Wider transport opportunities for existing communities

Key Theme 1: Potential Strategic Area access by public transport, walking and cycling

A E

B

C

D

Page 41: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 41

7. Strategic Area Interdependencies

Introduction 7.1. Development in one Strategic Area may be partially or fully dependent on development taking

place in another Strategic Area, perhaps relying on transport infrastructure to be provided in an adjacent area to allow for suitable access. This chapter identifies likely development interdependencies (relating to transport and accessibility) between the Strategic Areas and reviews the overall assessments in light of these interdependencies.

7.2. The meaning of interdependency in this Evidence Paper relates only to transport and accessibility factors and, importantly, relates to the long term planning strategy. Interdependency should not necessarily be used to imply development timing. If development in one Strategic Area is dependent on development in another then this does not necessarily mean that development has to take place later in the dependent area, providing that the long term strategy is to develop both Strategic Areas.

Dependency Analysis 7.3. At this high level assessment stage, the simplest method of presenting development dependency

is in the form of a ‘dependency matrix’. The matrix in Table 7-1 uses a three-point scale to identify the transport and accessibility dependencies which are likely to exist: little or no dependency (indicated by a ‘-‘ symbol); partial dependency; and high dependency.

7.4. Partial dependency implies that much of the Strategic Area is likely to be dependent on development taking place in another Strategic Area. High dependency implies that nearly all of the Strategic Area is likely to be dependent on development taking place elsewhere.

7.5. Where little or no dependency is shown in Table 7-1 (indicated by a ‘-‘ symbol), this should only be taken as indicative. Without knowledge of how many dwellings might be constructed in each Strategic Area, it is not possible to confirm that absolutely no dependencies exist. Interdependencies that, for example, are created as a result of uneven levels of growth might need to be assessed in a later more detailed assessment stage.

Table 7-1 Dependency Matrix

Strategic Area Y is...

Dependent On Strategic Area X (in transport and accessibility terms) Dependency Summary for

Strategic Area Y

A B C D E

A - - - - -

B Partially - - - Partial

C Highly Highly - - High

D - - - Highly High

E - - - - -

As an example, the matrix indicates that Strategic Area B is partially dependent on Strategic Area A.

7.6. The following key points provide explanations for the likely dependencies identified in Table 7-1:

The peripheral (north-eastern) parts of Strategic Area B are likely to be dependent on development taking place in Strategic Area A, to provide a suitable highway connection to the A350 (the PRN). Without this connection, nearly all traffic to or from Strategic Area B would need to route via Cocklebury Road and the town centre in order to connect with the PRN;

Most of Strategic Area C is likely to be dependent on development taking place in both Strategic Areas A and B. Again, this is to provide a suitable highway connection to the PRN

Page 42: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 42

via an eastern link road across the River Avon and railway line. Without this link road in place, nearly all traffic to or from Strategic Area C would need to route through or around Pewsham, and through Chippenham town centre. Although this dependency has been identified, it may be viable to develop limited southern parts of Strategic Area C as an extension to Pewsham; and

Most of Strategic Area D is likely to be dependent on development taking place within Strategic Area E, to provide a suitable highway connection (a southern link road) across the River Avon to the PRN at Lackham. Without this link road, nearly all traffic to or from Strategic Area D would need to route along the A4 around Pewsham, and through Chippenham town centre. As with Strategic Area C, it may be viable to develop limited parts of the area as an extension to Pewsham.

7.7. The Venn diagram at Figure 6-1 has been reviewed in light of the interdependencies that are likely to exist. This is to ensure that Strategic Areas which are partially or highly dependent on development in other Strategic Areas are not presented as being more favourable in transport and accessibility terms.

7.8. With Strategic Areas A and E identified as having little or no dependency on another area (Table 7-1) then these can remain in the central part of the Venn diagram, demonstrating favourable transport and accessibility attributes across all three key themes. The dependency that Strategic Area B has on Strategic Area A, and then in turn the dependency of Strategic Area C on Strategic Area B, is also already reflected in their positions in the Venn diagram. For these reasons, no modifications to the Venn diagram are considered necessary to reflect the interdependencies. This is confirmed in Figure 7-1.

Figure 7-1 Strategic Area Assessment – Final Venn Diagram

1

2

3

7

5

6

4

8

Key Theme 2: Potential Strategic Area highway access and

network impacts

Key Theme 3: Wider transport opportunities for existing communities

Key Theme 1: Potential Strategic Area access by public transport, walking and cycling

A E

B

C

D

Page 43: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

Chippenham Site Allocations Plan Transport & Accessibility Evidence Paper 3

Atkins Transport & Accessibility Evidence Paper 3 | Final | 23 October 2014 | 5131951 43

Potential Development Scenarios 7.9. Given the dependencies identified in this chapter, three potential long-term development

scenarios might be possible:

Scenario 1: Dispersed development, with growth spread across a number of Strategic Areas and without a full eastern or southern link road;

Scenario 2: North/east focus, with growth primarily occurring within Strategic Areas A, B and C, along with an eastern link road connecting the A4 at Pewsham with the A350 at Malmesbury Road; and

Scenario 3: Southern focus, with growth primarily occurring within Strategic Areas D and E, along with a southern link road connecting the A4 at Pewsham with the A350 at Lackham.

7.10. These three scenarios have been modelled using the Chippenham S-Paramics model, based on high level assumptions about growth within the Strategic Areas and potential link road arrangements. A scenario including both the eastern and southern link roads has not been modelled.

7.11. As the modelling has been undertaken without detailed knowledge of the growth that would be accommodated within each Strategic Area, and because the link road arrangements are not yet known, detailed modelling outputs are not presented in this Evidence Paper. However, the model outputs provide the following indications as to which scenario might be more favourable in transport and accessibility terms:

Scenario 1: A dispersed development scenario without full link roads is forecast to lead to the most congested conditions on the Chippenham highway network, using ‘average journey time’ and ‘time spent queuing’ as a proxies for congestion;

Scenario 2: A north/east development focus, with eastern link road, is forecast to lead to average journey times which are approximately 30-50% shorter than journey times under Scenario 1, or 15-20% shorter than under Scenario 3. Time spent queuing on approaches to The Bridge Centre is also forecast to be considerably lower than it is under both Scenarios 1 and 3; and

Scenario 3: A southern development focus, with southern link road, is forecast to lead to average journey times which are approximately 15-40% shorter (depending on the time of day) than journey times under Scenario 1. However, journey times under Scenario 3 are 20-25% longer than those under Scenario 2.

Summary 7.12. The analysis in this chapter has demonstrated that although development interdependencies are

likely to exist, these do not impact materially on the overall Strategic Area assessments presented in Chapter 6.

7.13. The analysis has also demonstrated that it would be possible to capitalise on the dependencies which exist between Strategic Areas A, B and C to deliver growth and supporting infrastructure which is more advantageous, in transport and accessibility terms, than completely dispersed growth.

7.14. Further scenarios will need to be tested to assess the impacts of more detailed potential patterns of development.

Page 44: Chippenham Site Allocations Plan - Wiltshire · information and use in relation to the Chippenham Site Allocations Plan. ... Rev 3.0 Revised Draft TP/KQ AP PC JFC 11/09/14 Final Final

© Atkins Ltd except where stated otherwise. The Atkins logo, ‘Carbon Critical Design’ and the strapline ‘Plan Design Enable’ are trademarks of Atkins Ltd.

Atkins The Hub 500 Park Avenue Aztec West BS32 4RZ