graven hill: phase 3 spine road (western)

Graven Hill: Phase 3 Spine Road (Western)

Road Safety Audit: Stage 1 & 2

September 2020

Waterman Infrastructure & Environment Limited

Halifax House, Halifax Place, Nottingham, NG1 1QN www.watermangroup.com

Disclaimer

This report has been prepared by Waterman Infrastructure & Environment Limited, with all reasonable skill, care and diligence within the terms of the Contract with the client, incorporation of our General Terms and Condition of Business and taking account of the resources devoted to us by agreement with the client.

We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above.

This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at its own risk.

Contents


WIE11386-147-1-2-3-RSA \\s-bm\WIEL\Projects\WIE11386_GH\0_LTA 2\#WO147_ROADS_OUTLINE_LTA2_Got PO\8_Reports\1. RSA\WIE11386-147-R-1-

2-3-RSA.docx

Contents

1. Introduction ................................................................................................................................. 1

2. Proposals and Information Provided ....................................................................................... 2

3. Matters Arising from This Audit ................................................................................................ 3

4. Audit Team Statement .............................................................................................................. 16

Appendices

A. List of Drawings and Documents Provided to the Audit Team

B. Problem Location Plan

1 Graven Hill: Phase 3 Spine Road (Western)

WIE11386-147-1-2-3-RSA

1. Introduction

This report is a Stage 1/2 Road Safety Audit (RSA) carried out on behalf of Graven Hill Village Development

Company Limited, regarding a proposed spine road at Graven Hill near Bicester.

The RSA team, staff members from Waterman, present at the RSA were:

Dave Prior BA (Hons), FCIHT, MRTPI, MSoRSA, MTPS, HE RSA Certificate of Competency

Audit Team Leader.

David Whalley BSc (Hons), MCIHT

Audit Team Member

We confirm that no member of the Audit Team has been involved with the design process

A site visit was carried out on Wednesday 9th September 2020 between 12:30 and 15:00. The weather

during the site visit was clear and dry. Traffic conditions were uncongested, with very low flows. It should

be noted that the audit team were unable to gain direct access to many parts of the scheme location due

to it being a controlled access live working site.

The terms of reference of the RSA are based upon the Design Manual for Roads and Bridges GG119

(previously HD19/15). – Road Safety Audit. The RSA team has examined and reported only the road

safety issues of the scheme as presented and has not examined or verified the compliance of the design

to any other criteria.

All of the problems described in this report are considered by the RSA team to require action in order to

improve the safety of the scheme and minimise collision occurrence. However, if any of the problems or

recommendations, within this Road Safety, Audit report are not accepted, a copy of the signed exception

report from the Overseeing Organisation should be sent to the Road Safety Audit Team Leader.


WIE11386-147-1-2-3-RSA

2. Proposals and Information Provided

This RSA considers the road safety of a proposed spine road (associated with Phase 3) at Graven Hill near

Bicester. Currently the site is owned and operated by the Ministry of Defence. For security reasons no

photographs of the site or problems identified by the Audit Team have been included within this report.

The proposed scheme includes a new spine road within the larger Graven Hill development. Provision is

made for a number of access roads from the spine road.

2.1 Documents and Drawings Provided

The drawings provided to the Audit Team are listed in Appendix A

2.2 Collision Data

No collision data has been provided to the audit team.

2.3 Documents and Information Not Provided

No Departures from Standards have been identified to the Audit Team.


WIE11386-147-1-2-3-RSA

3. Matters Arising from This Audit

3.1 Problem 3.1

3.1.1 Location and Scheme Drawing: Spine Road (limit of works) & Austin Way

Drawings: WIE11386-LTA2 Spine Road West-90-113-GA Sheet3 & 114-GA Sheet 4

3.1.2 Summary: No tactile paving provision

The Audit Team note that there are junctions located at the eastern extremity of the spine road and on

Austin Way, that have not been detailed with tactile paving or dropped kerbs. The introduction of such

facilities provides pedestrians a suitable location to cross the carriageway. Failure to introduce these may

result in pedestrians attempting to cross at unsuitable locations (particularly those who are visually

impaired), resulting in personal injury or conflict with approaching vehicles.

3.1.3 Recommendation

It is recommended that dropped kerbs and tactile paving are provided to enable pedestrians to safely

access the footway at all junctions along the spine road.


WIE11386-147-1-2-3-RSA

3.2 Problem 3.2

3.2.1 Location and Scheme Drawing: Spine Road / Health Hub Access Road

Drawing: WIE11386-LTA2 Spine Road West-90-113-GA_Sheet3 & 114-GA_Sheet4

3.2.2 Summary: Lack of provision for cyclists to exit the shared use footway/cycleway

The proposals include a 3m wide shared use footway/cycleway adjacent to the Graven Hill Health Hub

access road. The shared use footway/cycleway then reduces in width to 2m in the vicinity of the spine road.

At the transition point no provision is provided for cyclists to exit the shared use footway/cycleway. This

could lead cyclists to continue along the footway (when the cycle facility ends), thus bringing cyclists and

pedestrians closer together, resulting in collisions in close proximity to the road. Alternatively, it could result

in cyclists trying to dismount the full height kerb which could lead to cyclists losing control.

For cyclists travelling west along the spine road there is no provision for them to join the 3m wide shared

footway/cycleway which is proposed to the north of the spine road. This could result in cyclists trying to

mount the full height kerb which could lead to cyclists losing control. Alternatively, it could lead cyclists to

continue along the road exposing them to vehicular travelling for longer, increasing the risk of collisions

with vehicles.


Measures should be provided to enable cyclists to enter/exit the shared use footway/cycleway where it

starts/finishes and also to inform cyclists of the start/end of the shared use facility.


WIE11386-147-1-2-3-RSA

3.3 Problem 3.3

3.3.1 Location and Scheme Drawing: Spine Road / Health Hub Access Road

Drawing: WIE11386-LTA2 Spine Road West-90-113-GA_Sheet3

3.3.2 Summary: Pedestrain desire lines

The proposals include two dropped kerb crossing points on the spine road to the south of the Graven Hill

Health Hub access road. The crossing points lie circa 20m apart. To the east of the Graven Hill Health Hub

access road no crossing provision is provided. For movements from the north into the Graven Hill Health

Hub access road the crossing provision is considered to lie off of the likely pedestrian desire lines. Therefore

pedestrians travelling from the east would not use the crossings provided and could instead choose to cross

at more inappropriate locations. This could lead pedestrian slip/trip fall incidents as they mount/dismount

the kerb. This could also result in conflict between crossing pedestrians and vehicles, particularly as drivers

may not expect pedestrians to be crossing at these other locations.


It is recommended that crossing points are provided on the likely pedestrian desire lines. Specifically this

should include dropped kerb provision of the spine road to the east of the Graven Hill Health Hub access

road.


WIE11386-147-1-2-3-RSA

3.4 Problem 3.4

3.4.1 Location and Scheme Drawing: Health Hub Access Road & Austin Way

Drawing: WIE11386-LTA2 Spine Road West-90-111_Sheet1, 113-GA_Sheet3 & 114-GA_Sheet4

3.4.2 Summary: Angle of priority junctions

The proposals include two junctions that meet the main spine road or the Graven Hill Health Hub access

road at an acute angle. The acute angle of intersection of these junctions could make it more difficult for

motorists to see vehicles travelling on the main road, increasing the risk of vehicle collisions due to a failure

to give way.


It is recommended that the design team review the angles of each of the identified junctions and identify

measures to make the angle of intersection with the main road significantly less acute. This could possibly

be achieved through a localised realignment of the minor roads.


WIE11386-147-1-2-3-RSA

3.5 Problem 3.5

3.5.1 Location and Scheme Drawing: Various Locations

Drawing: WIE11386-LTA2 Spine Road West-90-111_Sheet1, 112-GA_Sheet2, 113-GA_Sheet3 & 114-

GA_Sheet4

3.5.2 Summary: Level and length of raised tables

No details have been provided to the audit team concerning the height of the proposed raised tables in

respect to the adjacent carriageway. Should the edge of the raised table be provided flush with the footway

this could create delineation issues and confusion for blind and partially sighted people. This could result

in an increase in collisions between pedestrians and vehicles.

Plateaus should also extend beyond any areas of tactile surfacing associated with any formal crossings

provided on the raised table. This is to help position visually impaired people using the crossing points away

from off/off ramp faces which may otherwise destabilise them. Failure to do so could result in pedestrian

slip, trip, fall incidents.


It is recommended that the design team review the details of the raised tables and also the location of each

of the pedestrian crossings in relation to the ramps etc.


WIE11386-147-1-2-3-RSA

3.6 Problem 3.6

3.6.1 Location and Scheme Drawing: Various Locations

Drawing: WIE11386-LTA2 Spine Road West-90-111_Sheet1, 112-GA_Sheet2, 113-GA_Sheet3 & 114-

GA_Sheet4

3.6.2 Summary: Increased severity collisions due to level difference

There is a significant level difference between the proposed spine road and the adjacent land to the south.

There is also a significant level difference between the Graven Hill Health Hub access road and the

drainage pond to the east. No indication of any protection measures for the drainage pond and slopes is

indicated on the drawings. Vehicles leaving the carriageway along this section (or pedestrians on the

footway) could therefore drop down the slopes to the adjacent land or the drainage pond. There would be

increased likelihood of vehicles overturning on the slopes or having increased severity of impact due to the

level difference. There is also a potential risk of drowning if errant vehicles were to enter the proposed

drainage pond.


The off-carriageway hazards should be assessed using the appropriate RRRAP process and protected by

a restraint system if necessary.


WIE11386-147-1-2-3-RSA

3.7 Problem 3.7

3.7.1 Location and Scheme Drawing: Access Road – Including Health Hub and Sports

Access (various locations)

Drawing: WIE11386-LTA2-90-1211_Rev A01 & WIE11386-LTA2-90-1212_Rev A01

3.7.2 Summary: Width of access roads

It is unclear from the information provided as to what quantum of development each of the access roads

provided from the spine road would serve. The suitability of these roads for their intended purposes is

therefore unclear.

The Audit Team note that the width of the Graven Hill Health Hub access road (5.5m) and Sports Access

road (4.8m) may not be appropriate, particularly when considering the curvature of these roads.

The proposed kerbline radii, coupled with the narrow road widths, may not be sufficient to enable all vehicle

types to use the road without overrunning the centreline or the adjacent footway/cycleway/verge. As a

consequence, large vehicles may collide with kerbing, items of street furniture, conflict with

pedestrians/cyclists using the adjacent footway/cycleways or overlap the centreline resulting in head on

vehicle collisions.


Undertake vehicle tracking at an appropriate design speed for the access roads and review the design to

ensure that the necessary swept path requirements are provided for.


WIE11386-147-1-2-3-RSA

3.8 Problem 3.8

3.8.1 Location and Scheme Drawing: Sports Access Road (various locations)

Drawing: WIE11386-LTA2 Spine Road West-90-113-GA_Sheet3

3.8.2 Summary: Incorrect tactile paving layout at crossings

The proposed tactile paving layout on the Sports Access road does not have the required minimum depth

of 800mm across the whole width of the crossing. This results in a lack of warning for visually impaired

pedestrians of the side road. This could lead to pedestrians directly entering the side road, increasing the

risk of pedestrian/vehicular collisions.


The tactile paving layouts should be amended to provide a minimum depth of 800mm tactile paving across

the whole width of the dropped kerbs at the crossings.


WIE11386-147-1-2-3-RSA

3.9 Problem 3.9

3.9.1 Location and Scheme Drawing: Spine road (various locations)

Drawing: WIE11386-LTA2 Spine Road West-90-111-GA_Sheet 1 & 113-GA_Sheet3

3.9.2 Summary: Lack of pedestrain crossing provision

The scheme appears to lack facilities for pedestrians to cross the spine road. For example, at the Sports

Access road there appears no provision (no tactile paving/dropped kerbs) for pedestrians to cross the spine

road. A lack of crossing facilities could result in pedestrians and cyclists crossing at inappropriate locations.

This could lead pedestrians to mount or dismount the full height kerb which could lead to pedestrian slip/trip

fall incidents. This could also result in increased likelihood of conflict between crossing pedestrians and

vehicles, particularly as drivers may not be expected people to be crossing and concentrating on the road

layout ahead.


Provision for pedestrians to cross the spine road at additional locations should be investigated and, where

required, provision should be made on the anticipated pedestrian desire line.


WIE11386-147-1-2-3-RSA

3.10 Problem 3.10

3.10.1 Location and Scheme Drawing: Spine road (various locations)

Drawing: WIE11386-LTA2 Spine Road West-90-211-Site Clearance_Sheet1 & 212-Site Clearance_Sheet2

3.10.2 Summary: Clearance of potential hazards

There appears to be a significant number of existing features including trees, vegetation, raised manholes

etc alongside the proposed spine road (outside of the limit of the S38 works). It is unclear if all of these

features would be removed as part of the scheme proposals. Failure to remove these features could provide

a hazard for vehicles leaving the carriageway, resulting in potential increased severity of injury.

It should be noted that the ability of the audit team to review this aspect on site was constrained by the

access restrictions incurred during the site visit.


Where features are not to be removed a RRRAP or similar assessment should be undertaken to determine

if vehicle restraint measures are required.


WIE11386-147-1-2-3-RSA

3.11 Problem 3.11

3.11.1 Location and Scheme Drawing: Spine road

Drawing: WIE11386-LTA2 Spine Road West-90-111-GA_Sheet 1

3.11.2 Summary: Road Alignment

Within the scheme drawings the kerbs and centre line markings on the spine road appear to tie three

straight lines together. This alignment takes opposing drivers very close to oncoming vehicles travelling

along the spine road. This could result in head on collisions with vehicles travelling in the opposite direction.


The kerb alignment and centre line markings should be reviewed and revised to provide a smoother

transition between the changes in carriageway width.


WIE11386-147-1-2-3-RSA

3.12 Problem 3.12

3.12.1 Location and Scheme Drawing: Austin Way

Drawing: WIE11386-LTA2 Spine Road West-90-114-GA_Sheet 4

3.12.2 Summary: Tactle paving alignment

The proposals include the provision of dropped kerbs and tactile paving along Austin Way. The proposed

dropped kerbs/tactile paving do not align. This could result in pedestrians crossing at a full height kerb

location. Pedestrians could trip as a result.


The dropped kerb provision should be aligned so as to provide pedestrians with a direct route.


WIE11386-147-1-2-3-RSA

3.13 Problem 3.13

3.13.1 Location and Scheme Drawing: Austin Way

Drawing: WIE11386-LTA2 Spine Road West-90-211-Site Clearance_Sheet 1

3.13.2 Summary: Site clearance schedule does not extend to limit of works

The site clearance schedule does not extend to the limit of the S38 works. Failure to clear any features

could provide a hazard for vehicles or obstruction to pedestrians therefore increasing the risk of collision

with an obstruction.


It is recommended that the site clearance schedule should be updated to include all areas within the limit

of the S38 works.


WIE11386-147-1-2-3-RSA

APPENDICES

A. List of Drawings and Documents Provided to the Audit Team


Project Number: WIE11386

Document Reference: WIE11386-147-1-2-3-RSA \\s-bm\WIEL\Projects\WIE11386_GH\0_LTA 2\#WO147_ROADS_OUTLINE_LTA2_Got PO\8_Reports\1. RSA\WIE11386-147-R-1-2-3-RSA.docx

B. Problem Location Plan

Problem 3.1

Problem 3.13




Note:

Problems 3.5-2.10 occur across the scheme. A full review should be undertaken.

Problem 3.1


WIE11386-147-1-2-3-RSA