Warwickshire County Council Format of talk · PDF file• Design issues at pedestrian...

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Warwickshire County Council

Signal Design, Safety Audit &Installation Practice

Gafoor Din IEng FIHE – Principal EngineerMichelle Fillingham IEng FIHE – Traffic Signal Design Engineer

Format of talk

• Propose of traffic control and information systems• Design Specification & Installation Practice• What is Road Safety Audit and Safety Review• Design issues at traffic signal junctions• Design issues at pedestrian crossings• Installation Practice

• Code of Practice• The Geometric Layout of Signal Controlled

Junctions TD 50/04• Work Specifications• Layout Drawings• Dropped Kerbs & Tactile Surfaces• Ducting & Chambers

Signal DesignSpecification & Installation Practice

• Signal Poles & Lanterns• Detection• Cabling & Terminating• Questions

• Improving safety• Improve network management• Better travel and traveller information• Better public transport• More efficient freight transport• Reducing environmental impact

OBJECTIVES TOOLS

Local Transport Plan (LTP 3)DfT ITS Policy

Delivering Outcomes notImplementing Technology

Propose of traffic control and information systems

• Improving safety• Improved asset management• Better maintenance• Better network management

OBJECTIVES AUXILIARY EQUIPMENT

Design Manual for Road BridgesTraffic Advisory Leaflets

Delivering Sustainable Infrastructurenot just a Scheme

How do we get from here?

To Here?

The Code of Practice for Traffic Control &Information Systems TA84/06

TA 84/06 Volume 8, Section 1, Part 2.

CODE OF PRACTICE FOR TRAFFIC CONTROL AND INFORMATION SYSTEMS

The Geometric Layout of Signal-ControlledJunctions and Signalised Roundabouts

TD 50/04

https://www.gov.uk/government/publications/local-transport-notes

https://www.gov.uk/government/collections/traffic-advisory-leaflets

http://www.dft.gov.uk/ha/standards/dmrb/

• Visibility to a signal heads at a traffic signal junctionTD 50/04

Signal head positions

Example for 40mph SSD is 120m

Work Specifications

Programming the Work

Layout Drawings

Standard Key

www.theihe.org - Traffic Signal Control course - Conference Aston Birmingham - 29th April to May 2nd 2013

Standard Key

Type of Phases

Typical 2 Stage control

Permitted stage changes

Dummy Phase

Dropped Kerbs and Tactile Surfaces atPedestrian Crossing Points

The preferred gradientis 5% or 1:20

Fully Ducted System

Topographic Survey

AGDElectricity

Controller

SupplyCable

BoxSign

Draw up as Schematic

Retention Socket

STAKKA Box

High Friction Surfacing (HFS) – TD 50/04 (DMRB 6.2.3)

HD 36/06 (DMRB 7.5.1) – Polished Stone Value (PSV)

The Manual of Contract Documents for Highway Works (MCHW)Volume 3 - Highway Construction Details

G Series

Some Bad, Some Dangerous!

Safety Audit Definition

A formal procedure for the independent evaluation ofhighway schemes before implementation to identifypotential safety hazards which may affect road usersand to suggest measures to eliminate or mitigate thoseproblems

• An independent review of the design• Ensure that all safety related issues have been

addressed• Make recommendations

Safety Audit are carried out in four stages –HD 19/15 – DMRB Vol 5, Section 2, Part 2

• Stage 1 :- Completion of preliminary design(before publication of draft orders)

• Stage 2 :- Completion of detailed design(before invitation to tender)

• Stage 3 :- Completion of construction(before opening)

• Stage 4 :- Monitoring reports shall be prepared using12 months and 36 months of accident data

The Scope of the Audit :

• Aim to minimise accident frequency and severity• NOT a design standards or technical check!• Who can be hurt here and why?

Safety Review Definition

An independent review of the safety aspects of a systemcarried out after the preliminary design stage and againafter the detailed design stage.

These reviews runs in parallel with and may becombined with, the Stage 1 and Stage 2 Safety Auditsextended to cover the control and operational aspects ofthe proposed system.

Exact location of traffic signal equipmentController Specification FormMethod of controlTiming sheets for crossingsTraffic model (Oscady, LinSig, Transyt, Paramics)

TAL 1/06 – General Principles of Traffic Control by Lights Signalswww.gov.uk/government/collections/traffic-advisory-leaflets

TAL 5/05 – Pedestrian Facilities at Signal-Controlled Junctions

Traffic – TAL 1/06 (part 4 of 4)Pedestrians – TAL 5/05 (part 4 of 4)

0 1 2 3 4 5 6

Intergreen = 6 secs

Intergreen from Phase A to E

Pedestrian to Traffic

Pedestrian

Traffic

0 1 2 3 4 5 6 7 8 9 10

Intergreen = 10 secs

2 second blackout – Warwickshire

Pedestrian

Traffic

Intergreen = 8 secs

0 1 2 3 4 5 6 7 8

TR 2581A

Pedestrian to Traffic

Pedestrian

Traffic

8 7 6 5 4 3 2 1

Intergreen = 10 secs

4 seconds

7 seconds

33 seconds

Minimum cycle times

Cycle Time

Maximum cycle times

Signal head positions

• Close Associated Secondary

• Local alignment

Method of Control

• Manual• Fixed Time• VA (Vehicle Actuated)• CLF (Cableless Linking Facility)• UTC/SCOOT• MOVA

Detection TypeLTN 2/95

• When the 85% tile approach speeds exceeds65mph it is recommended that traffic signalsshould not be installed

• Right turns should be controlled separatelywhen the 85% tile approach speeds exceeds45mph

• Duplicate primary signals

TAL 2/03 – Signal-control at junctions onHigh-Speed Roads

Detection – MOVA loops

• Improve traffic flow• Distance calculated

for individual sites• Can also be used at

high speed locationsinstead of x, y z andspeed discrimination /assessment loops

• Increase intergreenby 1 sec

Detection – MOVA loops

Trixi Mirrors

LTN 1/95 – The Assessment of PedestrianCrossing

• Zebra crossings are only appropriate for roads wherethe 85% tile speeds is less than or equal to 35mph

• Signaled crossings are only appropriate for roadswhere the 85% tile speeds is less than or equal to50mph

Location of crossing – on major road near junction

• Should be located awayfrom conflict points atuncontrolled junctions

• ‘Safe’ distance willdepend on junctiongeometry

• Minimum of 20msuggested for signalcontrolled crossing

• Absolute minimum of 5mfor a zebra crossing

Minimum width stagger island = 2.8m min

Forward Demand P1 and P6

Lighting for crossings

• May need to improve/supplement the lighting• ILE Technical Report No. 12• BS5489-1 2003, Section 11, and BS EN 13201-

2 2003, Annex B.• Can drivers see pedestrians/cycles waiting to

cross• Consult a lighting engineer

Signal Poles & Lanterns

Traffic Signal Poles

www.theihe.org | TrafficSignal Control Course

1.0m to1.01m

2.4m on Cycle Path

Cabling & Terminating

Questions?

gafoordin@warwickshire.gov.ukmichelle.fillingham@bournemouth.gov.uk