2. Targeting Speed Limits by Michael Tziotis

Learning, Engaging and Acting!

Michael Tziotis, Manager Safe Systems

Targeting Speed Limits –Is there a case for lowering speed limits?

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What do we know about speed and crashes?

Source: Centre for Automotive Research (CASR) SA

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Human tolerance to harmChances of surviving a crash decrease

rapidly above certain impact speed -• car / pedestrian 20 to 30 km/h• car / motorcycle 20 to 30 km/h• car / pole or tree 30 to 40 km/h• car / car (side-impact) 50 km/h• car / car (head-on) 70 km/h

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Travel speed, stopping distance and crash impact speed

Source: VicRoads

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Changes in mean speed and changes in crash risk

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

-10% -8% -6% -4% -2% 0% 2% 4% 6% 8% 10%

% change in speed

% c

han

ge

in c

asu

alti

es

DeathsSerious injuriesOther injuries

Source: Elvik et al. (2004)

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0

5

10

15

20

25

30

35

-15 -10 -5 0 5 10 15 20

Change from the average free speed (km/h)

Rel

ativ

e ri

sk o

f a

casu

alty

cra

sh

60 km/h urban roads

80-110 km/h rural roads

Source: Jurewicz (2009) after Kloeden et al. (2001) and (2002)

Crash risk and speeding

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Evaluation of the 50km/h local street speed limit in NSW – all casualty cashes

0

50

100

150

200

250

Sep-94 Dec-94 Mar-95 Jun-95 Sep-95 Dec-95 Mar-96 Jun-96 Sep-96 Dec-96 Mar-97 Jun-97 Sep-97 Dec-97 Mar-98 Jun-98 Sep-98 Dec-98 Mar-99 Jun-99 Sep-99 Dec-99

Year and month

Nu

mb

er o

f ca

sual

ties

on

50

km/h

str

eets

in T

rial

LG

As,

or

sim

ilar

stre

ets

in t

he

con

tro

l LG

As

Control LGAs

Trial LGAs

Estimated casualties (Control LGAs)

Estimated casualties (Trial LGAs)

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Evaluation of the 50km/h local street speed limit in NSW – actual vs expected

-202.3

-106

-258.7

-300

-250

-200

-150

-100

-50

0

50

Trial LGAs

Dif

fere

nce

in

th

e n

um

ber

of

acci

den

ts

exp

ecte

d c

om

par

ed t

o t

he

actu

al n

um

ber

of

acci

den

ts

UrbanTrial

RuralTrial

Combined Rural and Urban Trial

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Lessons - speed limits LOWERED?

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Lessons - speed limits RAISED?

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NEXT STEP ACTING

Thank You!