Red light cameras revisited. Recent evidence on red light camera safety effects

Area of Science:

• Traffic safety engineering
• Transportation research
• Public health

Background:

• Red light cameras (RLCs) and speed/red light cameras (SRLCs) are implemented to improve road safety.
• Previous meta-analyses provide summary estimates of their effectiveness.
• An update on recent evidence is needed to reflect current trends.

Purpose of the Study:

• To synthesize the latest evidence on the road safety performance of RLCs and SRLCs.
• To compare recent safety estimates with findings from earlier meta-analyses.
• To identify trends in camera effectiveness over time.

Main Methods:

• A systematic literature search was conducted for RLC and SRLC studies published between 2013 and 2017.
• 18 relevant studies were identified and their methodologies and results were analyzed.
• Summary safety estimates were calculated and compared to previous meta-analysis results.

Main Results:

• Recent studies indicate a 12% decrease in total crashes associated with RLCs and SRLCs.
• RLCs continue to reduce right-angle crashes but increase rear-end collisions.
• Safety effects appear to improve over time, with the most recent studies showing the greatest impact.
• SRLCs demonstrate more positive safety effects compared to RLCs.
• Significant spillover effects from camera enforcement are commonly observed.

Conclusions:

• Red light cameras and speed/red light cameras are effective in reducing overall crashes, with effectiveness increasing over time.
• Speed/red light cameras show greater safety benefits than red light cameras alone.
• The positive safety impacts of these camera systems, including spillover effects, are substantial and warrant continued monitoring.