Purpose of research

To assess the economic costs and benefits of traffic signals in London

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Contents Context

Methodology

Selected Junctions for Assessment

Results

Conclusions and recommendations

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Context Number of traffic signals

steadily increased - 1,000 new sets since 2000

There are 2,500+ signalised road junctions in Greater London.

Roughly split 50:50 between inner and outer-London with two thirds on non-TfL roads.

Perception too many - their benefits may be outweighed by increased congestion

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Context Mayor is committed to

tackling congestion by ensuring smoother traffic flow

TfL reviews all London traffic signals to ensure that they operate in the most efficient way

TfL has examined various options for reducing the impact of traffic signals

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TfL roads

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Signalised junctions in Greater London

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1

2

3

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List of selected junctions

Key Location Type of junction

1 A5 Edgware Road Series of 4 Arm Junctions2 (A312/B455)-Target RB Roundabout3 A13 River Road - Bastable Avenue 3 Arm (T junction)4 East Barnet Road / Margaret Road 4 Arm5 A215 Norwood Road - Palace Road 3 Arm (T junction)

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Traffic mixHourly variation in traffic flow - all vehicles

0

500

1000

1500

2000

2500

00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00

Edgware NB

Edgware SB

East Barnet NB

East Barnet SB

West Norwood NB

West Norwood SB

A13(WB)

A13(EB)

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Alternate method of controlControl Regime

AnarchicOr

Filter-in-Turn: in order of arrivalOr

Off-Side priority rulesOr

Major/Minor priority controls

Degree of ControlNone – individual decisionsOr

Regulated – through signsOr

Partial Control – through self activated signal controlsVehicle to Pedestrian control

regulation

Pedestrian PriorityOr

Partial Control – through self activated signal controls

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VISSIM models – existing scenario

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Location of Edgware Road junctions

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Edgware Road corridor

All junctions 4-Arm Crossroads junction

Corridor of signalised junctions in Inner London

Heavy traffic in all time periods

High volume of pedestrians and cyclists

Main corridor is on TLRN

8 Junctions in corridor

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Edgware Road VISSIM results

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Target Roundabout – Church Road

4-Arm Roundabout in Outer London

Surrounding area is mainly residential

Low volume of pedestrians and cyclists

On TLRN

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Target Roundabout VISSIM results

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VISSIM model – without signals

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A13 River Road / Bastable Avenue

3-Arm Junction in Outer London

Surrounding land-use is mixed with residential/ commercial

Low volume of pedestrians and cyclists

Non-TLRN

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A13 River Road VISSIM Results

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East Barnet Road / Margaret Road

4 Arm junction in Outer London

Surrounding land-use is mainly residential

Low volume of pedestrians and cyclists

NOT on strategic network

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East Barnet VISSIM Results

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A215 Norwood Road/ Palace Road

3 Arm junction in Outer London

Surrounding area is mainly residential

High volume of pedestrians due to proximity to railway station

Low volume of cyclists

Non-TLRN

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West Norwood VISSIM results

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A41/ Church Road vehicle/value comparison – morning peak

Total VOT for all modes

Average VOT per vehicle (pence)

A41 £275 20.2

Church Road £213 15.5

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Economic impactQuantified impacts include:

Time savings – based on changes in delay time, valued using standard parameters

Vehicle operating costs (fuel & non-fuel) – largely based on changes in speed

Emissions – related to the rate of fuel consumption

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Impact of removing traffic signals: Edgware Road

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Impact of removing traffic signals: Target Roundabout

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Impact of removing traffic signals: A13

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Impact of removing traffic signals: East Barnet Junction

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Impact of removing traffic signals: Norwood Road Junction

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Impact of removing traffic signals: all junctions

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Issues Can we scale up to an all-London total?

How do we account for

Safety ?

Pedestrians ?

Predicting driver and pedestrian behaviour in partially controlled regime ?

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Conclusions & recommendations significant benefits to road users from traffic signals in London

benefits of removing traffic signals in certain locations and at certain times provided safety is not compromised

recommend pilot to switch off traffic signals at times when level of traffic does not justify them - subject to a safety audit

recommend discussions with European traffic authorities to obtain evidence on use of flashing amber signals on safety, vehicle and pedestrian movement

traffic modelling assumes conventional priority control when signals are removed. Maybe junctions could operate without any regulated traffic controls but this behaviour cannot, at present, be modelled

need live trials at a variety of sites, results would have the potential of determining how traffic and pedestrians behave in ‘shared space’