Drivers’ behavioural responses to combined speed and red light cameras

  • Published: Accident Analysis & Prevention, Volume 81, August 2015
  • Authors: E. Polders, J. Cornu, T. De Ceuynck, S. Daniels, K. Brijs, T. Brijs, E. Hermans, G. Wets
  • Date Added: 11 Feb 2016
  • Last Update: 11 Feb 2016
  • Format: html


To provide a better insight into possible explaining factors for the increase in rear-end collisions associated with the placement of speed and red light cameras (SRLCs)


Real-world observations and driving simulator-based observations were combined.

Key Findings:

  • Video recordings at two signalised intersections where speed and red light cameras (SRLCs) were about to be installed were used to analyse rear-end conflicts, interactions and driver behaviour in two conditions: with and without SRLCs. Furthermore, one of these intersections was rebuilt in a driving simulator equipped with an eye tracking system. At this location, two test conditions (just SRLC and SRLC with a warning sign) and one control condition (no SRLC) were examined. The data of 63 participants were used to estimate the risk of rear-end collisions by means of a Monte Carlo Simulation.

  • The results of the on-site observation study revealed decreases in the number of red and amber light violations, a shift (closer to the stop line) in the dilemma zone and a time headway reduction after the installation of the SRLC. Based on the driving simulator data, the odds of rear-end collisions (comparted to the control condition) for the conditions with SRLC and SRLC plus warning sign are 6.42 and 4.01 respectively.

  • The driving simulator identified possible adverse effects on road user behaviour, such as stronger decelerations, and a possible increase in the number of rear-end collisions. However, in the case where the presence of SRLCs is announced with warning signs, these adverse effects are somewhat reduced.


Robust experiment using driver observation and simulator data.