Chichester City Centre North Gyratory RSA a...Dec 15, 2014 · Figure 7 from the Specification for a Cycle Detection and Warning Sign System for Chichester Northgate Gyratory has

COPYRIGHT 2013 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Stage 2a Road Sa fe ty Aud i t

Chichester City Centre North Gyratory RSA�a

Document: ��.IE. !/RSA�a Version: !

Prepared for

West Sussex County Council

15 December 2014

Burderop Park

Swindon

Wiltshire

SN4 0QD

20141215_STAGE2A_RSA_CHICHESTER NORTH GYRATORY FINAL.DOC COPYRIGHT 2013 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL

Stage 2a Road Sa fe ty Aud i t

Chichester City Centre North Gyratory RSA�a

Document: ��.IE. !/RSA�a Version: !

Prepared for


15 December 2014

CH2M HILL ELMS HOUSE, 43 BROOK GREEN, LONDON W6 7EF TEL +44 20 3479 8000 FAX +44 20 3479 8001 CH2MHILL.COM CH2M HILL HAS PREPARED THIS REPORT IN ACCORDANCE WITH THE INSTRUCTIONS OF WEST SUSSEX COUNTY COUNCIL FOR THE CLIENT’S SOLE AND SPECIFIC USE. ANY OTHER PERSONS WHO USE ANY INFORMATION CONTAINED HEREIN DO SO AT THEIR OWN RISK.

Contents


Document history

Stage 2a Road Safety Audit

Chichester City Centre North Gyratory


This document has been issued and amended as follows:

Version Date Description Created by Verified by Approved by

1.0 15/12/14 DRAFT Alison Foale Daniel Harris Alison Foale

1.0 16/12/14 FINAL Alison Foale Daniel Harris Alison Foale

Contents


Contents

Section Page

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

Road Signs, Carriageway Markings and Lighting ............................................................................ 2

2.1 Road Signs .................................................................................................................................. 2

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

Appendices

A List of Drawings and Supplied Documents

B Location Plan

C Key Plan


Introduction

This report results from a Stage 2a Road Safety Audit carried out on the Chichester City Centre North

Gyratory scheme prepared by CH2M Hill for West Sussex County Council.

A Stage 2 Road Safety Audit was undertaken in August 2013 and considered proposed alterations to the

cycle provision and road markings at the northern gyratory to give cyclists priority on the circulatory

carriageway. This included the provision of vehicle activated ‘Think Bike’ signs although at the time the

position of these signs was unconfirmed. Suggested locations have now been provided and this Stage 2a

Road Safety Audit only considers this aspect of the scheme.

The Audit Team membership was as follows: -

Alison Foale BEng (Hons) MSc MCIHT MSoRSA – CH2M Hill, Swindon

Daniel Harris BA (Hons) MCIHT MSoRSA – CH2M Hill, Swindon

The Audit Team has examined and reported only on the road safety implications of the design and has not

examined or verified the compliance of the layout to any other criteria, in accordance with HD 19/03.

A visit to the site was made on Tuesday 13th August 2013 as part of the Stage 2 audit however a site visit

has not been undertaken as part of this Stage 2a audit.

Figure 7 from the Specification for a Cycle Detection and Warning Sign System for Chichester Northgate

Gyratory has been provided. The Audit Team have referenced each of the suggested locations for a vehicle

activated sign by a letter from a to l. These have been used to reference the locations in this report.

A list of Drawings and Documents supplied to the Audit Team is available in Appendix A and a Location Plan

in Appendix B.

Each of the problems identified by the Audit Team has been allocated a unique reference number and is as

shown on the plan extracts contained within Appendix C.


Road Signs, Carriageway Markings and Lighting

�.! Road Signs

�.!.! Location: Scheme wide

Summary: Mounting heights

It is not clear from the Figure 7 in the Specification for a Cycle Detection and Warning Sign System

for Chichester Northgate Gyratory how and at what height the vehicle activated signs (VAS) are to

be mounted. At some locations the signs will be within footway or adjacent to cycleways and

could be at risk of being struck and causing injury.

Recommendation

Ensure that the VAS are mounted at appropriate heights.

�.!.� Location: Position of detection areas

Summary: Effectiveness of VAS

The detection areas are located at varying distances from the gyratory approach arms. It is not

clear how long the VAS remain illuminated once a cyclist is detected. The Audit Team are

concerned that the signs could have turned off before the cyclist is in the vicinity of the approach

or remain on when there is no cyclist, reducing the effectiveness of the signs.

Recommendation

Ensure that the VAS are illuminated when a cyclist is expected to be in the vicinity of the

approach to ensure that drivers don’t become complacent to the message.

�.!.. Location: Scheme wide

Summary: Position of VAS

A number of the proposed locations for the VAS could result in the sign being partially obscured

by other signs or vegetation reducing the effectiveness of the signs. The VAS signs are not

supported by static signs in the event of the VAS not operating.

Sign c) is located in close proximity to an existing warning sign for the fire station which could

partially obscure it.

Signs d and f) could be obscured by existing trees/vegetation.

Sign l) is located in close proximity to an existing ‘Think Bike’ static sign. The exact location of the

VAS is not clear and could be partially obscured.

Recommendation

Ensure that the VAS are positioned such that forward visibility to the signs is not compromised by

existing signs or vegetation.

Provide static signing to support the VAS when non-operational.


�.!.� Location: Circulatory Carriageway

Summary: Purpose of some VAS

The Audit Team understood that the purpose of the VAS was to alert drivers to cyclists

approaching the main conflict points at the entries to the gyratory. However the position of the

VAS opposite the approaches may not provide sufficient warning to drivers particularly where

there are two approach lanes or the signs are positioned significantly to the right for example

sign reference c.

Some of the VAS located midway along the circulatory between entries appear to be activated by

detection areas immediately infront of the sign. This may not provide sufficient warning to

motorists reducing the effectiveness for example signs b, d and h.

Recommendation

Provide VAS signs on all approaches to the gyratory.

Ensure that the VAS signs are activated sufficiently in advance to provide drivers with adequate

warning of a cyclist.


Audit Team Statement

I certify that this audit has been carried out in accordance with HD 19/03.

Audit Team Leader

Name: Alison Foale Signed:

Dated: 15/12/2014

Position: Senior Consultant

Organisation: CH2M Hill

Address : Burderop Park, Swindon, SN4 0QD

Audit Team Member

Name: Daniel Harris

Position: Consultant

Organisation: CH2M Hill

Address: Burderop Park, Swindon, SN4 0QD


Appendix A List of Drawings and Documents Supplied

Document Rev. Description

Revised Figure 7 - Suggested Site equipment locations and connectivity (12 signs)

Specification for a Cycle Detection and Warning Sign System for Chichester Northgate Gyratory, Nov 2014


Appendix B Location Plan

Chichester City Centre North Gyratory


Appendix C Key Plan

Scheme

wide

2.1.1

2.1.2

2.1.3

2.1.4

a

b c

d

i

g

e

f

j

l

k

a

h