Overview

November 2002

ISA across Europe

isa- UKintelligent speed adaptation

isa- UKintelligent speed adaptation

Trials around Europe - S

S

Active accelerator

Warning system “speed checker” Umeå

Sweden

Swedish findings and strategy Accident prediction in line

with earlier UK report National map to be created ISA will be fitted to SNRA

fleet Agreement to be secured

with car industry by 2005 to fit all new vehicles as of 2010

If no agreement is obtained, then the Minister has said he will push for a directive

ISA around Euope – NL & DK

50 km/h - you are driving to fastDK o

NL

Driver acceptability and Technical possibilities

Comparison of different designs

New projects in:

France (with involvement of Renault and Peugeot/Citroen)

Belgium (2 projects)

UK research on ISA DETR funded External Vehicle Speed Control (EVSC) project,

1997-2000 Develop a technical specification of a future system Assess legal implications and acceptability Study driver behaviour Predict accident savings and side effects (congestion, fuel

consumption, emissions) Design an implementation strategy

DfT funded ISA project, 2001-05 Field trials with 20 vehicles Further experimental work Technology development Motorcycle and large truck demonstrators

Driver behaviour with ISA

On-road trials in EVSC (external vehicle speed control)

72 drives 42 mile route Route covered all road

categories and all speed limits except 20 mph

2 ISA variants studied — voluntary and mandatory

Speed profile (mandatory system) in rural area

0

10

20

30

40

50

60

70

4 5 6 7 8 9 10Distance along route (miles)

Sp

eed

(m

ph

)

Without ISA

With ISA

roundabout

village (40mph)

village (40mph)

Negative interactions and conflicts

Run 1Run 2

Run 3

Mandatory

Voluntary

Baseline

0

5

10

15

20

25

Findings from on-road trials Driver speed was mostly dictated by

road geometry and traffic ISA most effective in urban areas/rural

villages Drivers thought the voluntary system

was preferable Drivers did not feel “out of the loop” or

exhibit signs of being so

Accident Prediction and Implementation Path

Changes in distribution of speeds

Advisory speed limiter:change in mean speed

0

0.01

0.02

0.03

0.04

-3 -2 -1 0 1 2 3

Fre

qu

ency

Norm Dist

Translation

Mandatory speed limiter:change in shape ofdistribution

0

0.1

0.2

0.3

0.4

0.5

0.6

-3 -2 -1 0 1 2 3

Fre

qu

ency

Norm Dist

Transformation

Formulae used for accident prediction

Mean speed:For each 1 mph change in mean speed the change in accident risk is as follows (derived from Finch et al., 1994): Low estimate 3.75% Best estimate 5.00% High estimate 9.70%

Speed variance:The formula applied for the relationship between speed variance and risk was derived from West and Dunn (1971) and is:

y = 0.0139x2 + 0.0140x

where y is relative riskand x is the speed difference of a vehicle from mean speed in mph

Predicted accident reduction from ISA for GB Advisory:

information only Driver Select:

voluntary control Mandatory:

speed limited all the time

Fixed:limits as now (posted)

Variable:+ lower where needed

Dynamic:+ lower when needed

Speed Limit System Intervention Level

Fixed Variable Dynamic

Advisory 10% 10% 13%

Driver Select 10% 11% 18%

Mandatory 20% 22% 36%

59%reduction

in fatal accidents

Other benefits

Annual saved fuel consumption:Petrol £198mDiesel £117m

Costs

Information supply Create digital road maps Maintain road maps Distribute road maps (Broadcast current speed limits) On-board system to locate vehicle

Control on the vehicle HMI

B/C ratios for alternative versions of ISA

Low GDP Growth High GDP Growth System

Fixed Variable Dynamic Fixed Variable Dynamic

Advisory 5.0 5.3 7.0 6.9 7.2 9.6

Driver Select 3.7 4.0 6.1 5.0 5.4 8.3

Mandatory 7.4 8.0 12.2 10.0 10.9 16.7

2000 2020

The recommended implementation scenario from the EVSC project

Voluntary usage

2019Mandatory usage

Manufacture 2013Production

2010

Standards

Standards enacted

2005

Research

Decision

This gives time for implementing dynamic ISA