Speed kills 2 but people like speed! 3 Speed Higher speeds are - - PDF document

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Speed kills 2 but people like speed! 3 Speed Higher speeds are - - PDF document

Dec 10, 2023 311 likes •418 views

Effects of automated highway speed enforcement: average versus instantaneous speed control 27 th annual ICTCT workshop 16-17 Oct 2014, Karlsruhe - Germany dr. Stijn Daniels, PhD Transportation Research Institute Hasselt University, Belgium

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SLIDE 1

Effects of automated highway speed enforcement: average versus instantaneous speed control

27th annual ICTCT workshop 16-17 Oct 2014, Karlsruhe - Germany

  • dr. Stijn Daniels, PhD

Transportation Research Institute Hasselt University, Belgium stijn.daniels@uhasselt.be

Speed kills…

2

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SLIDE 2

…but people like speed!

3

Speed

Higher speeds are associated with higher risks (Aarts & van Schagen, 2006) Road users are well aware of this (SARTRE 3,

2004)

Yet road users continue to drive too fast

(ETSC, 2011)

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SLIDE 3

Solutions?

‘Safe’ speed limits Public awareness Road design Vehicle technology Enforcement

Enforcement

Manual/automated Visible / non-visible Point control vs. section control

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SLIDE 4

Speed enforcement effective?

Fixed speed cameras reduce speeds (Retting et

al., 2008; Liu et al., 2011)

Fixed speed cameras reduce crashes (Elvik et al.,

2009):

All crashes: -16% Fatal crashes: -39%

Section control: high compliance rates + crash reductions (Soole et al., 2013) But:

Effects local or also at a larger distance? Section control better than point control?

Objectives of the study

Speed cameras on motorways

Effect on speed? Effect on crashes?

Section speed control on motorways

Effect on speed? Effect on crashes?

Speed cameras vs. section control

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SLIDE 5

Effects of fixed cameras on speed behaviour

+3,5 km + 1 km a t i n f

  • r

m a t i

  • n

s i g n

  • 2,5 km

at camera

  • Before-after study with control for

trend

  • Research locations
  • 2 locations with speed cameras
  • Motorways, Vmax = 120 km/h
  • Measurements at 5 points
  • Only free flow moments

Speed effect: V-profile

  • Clear speed decreases at camera location
  • No substantial effects up- or downstream no spill-over

effects

  • Considerable speed differences at short distances

“kangaroo-effect”

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SLIDE 6

Direction of Ghent Direction of Brussels +2,3 km

  • 6,4 km
  • 0,6 km
  • 2,3 km
  • 1,7 km

+0,6 km +6,4 km

  • n section
  • n section
  • Before-after study with control for trend
  • Research locations
  • 2 segments with section control
  • Motorways, Vmax = 120 km/h
  • Measurements at 5 points
  • Only free flow moments

Effect of section control on speed behaviour Effect of section control on speed behaviour

  • More homogenous

speed reductions

  • Indications for spillover

effects

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SLIDE 7

Safety effects of speed cameras

13

Results

  • 1200 m up to +200 m: increases in crash numbers
  • +200 to + 5000 m: ambiguous results
  • Separate analysis: side crashes and rear-end crashes

increase, single-vehicle crashes decrease

PDO-crashes (property damage

  • nly)

Injury crashes Severe injury crashes

  • 1200 tot +200 m

+53%

1,53 [1,39; 1,69]

+30%

1,30 [1,10; 1,55]

(+42%)

1,42 [0,98; 2,05]

+200 tot +5000 m

+27%

1,27 [1,19; 1,36]

  • 20%

0,80 [0,71; 0,90]

(+13%)

1,13 [0,91; 1,42]

  • Crash data 2003-2011
  • 27 camera sites
  • Empirical Bayes before- and afterstudy
  • Correction for regression to the mean by means of CPM (Van Hout et

al., 2013)

  • Comparison group: crashes on motorways > 20 km

Safety effects of section control

14

All crashes PDO (property damage

  • nly)-crashes

Injury crashes Section

(-26%)

0,74 [0,53; 1,04]

(-18%)

0,82 [0,53; 1,27]

(-31%)

0,69 [0,40; 1,18]

Section +2km

(-17%)

0,83 [0,64; 1,07]

(-2%)

0,98 [0,72; 1,33]

(-35%)

0,65 [0,41; 1,02]

Section +5km

(-6%)

0,94 [0,77; 1,14]

(+1%)

1,01 [0,79; 1,30]

(-15%)

0,85 [0,60; 1,20]

  • Before after analysis with comparison group
  • 2 enforced segments (7.4 km each)
  • Before period: Jan 2007- Sep 2012
  • After period: Apr 2013- Dec 2013
  • Consistent effects, but not significant => preliminary!
  • Crash decreases, in particular injury crashes
  • Indication of some spillover effects

Results:

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SLIDE 8

Conclusions

Fixed speed cameras at motorways

V-profile of speeds Ambiguous till adverse effects on crashes

Section control

Homogenous speed reductions Indications for spillover effects (Preliminary) favourable effects on crashes

15

Thank you. Questions?

27th annual ICTCT workshop 16-17 Oct 2014, Karlsruhe - Germany

  • dr. Stijn Daniels, PhD

Transportation Research Institute Hasselt University, Belgium stijn.daniels@uhasselt.be

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SLIDE 9

Publications

  • De Pauw, E. , Daniels, S., Brijs, T., Hermans, E., & Wets, G.

(2014). Automated section speed control on motorways: An evaluation of the effect on driving speed. Accident Analysis & Prevention, 73, 313–322.

  • De Pauw, E., Daniels, S., Brijs, T., Hermans, E., & Wets, G.

(2014). Behavioural effects of fixed speed cameras on motorways: Overall improved speed compliance or kangaroo jumps? Accident Analysis & Prevention, 73, 132–140.

  • De Pauw, E., Daniels, S., Brijs, T., Hermans, E., & Wets, G.

(submitted). Safety effects of fixed speed cameras on motorways in Flanders, Belgium: Empirical results.