Effectiveness of LED stop lamps for reducing rear-end crashes: analyses of state crash data
- Published: U.S. Department of Transportation, National Highway Traffic Safety Administration (NHTSA); Report number DOT HS 811 712, 2013
- Authors: Greenwell N K
- Date Added: 25 Jan 2014
- Last Update: 25 Jan 2014
To analyse the crash-reduction benefits of LED (light-emitting diode) stop lamps and LED centre high-mounted stop lamps (CHMSL) using real-world crash data.
NHTSA statistically compared the overall ratio of rear-impact crashes to a control group of frontal impacts before and after the switch to LED.
Overall, the analysis does not support a firm conclusion about whether LED stop lamps and LED CHMSL are more effective than incandescent lamps.
The main analysis shows a significant overall 3.6% reduction in rear-impact crashes with LED.
On the other hand, a non-parametric analysis not only fails to show improvement in significantly more than half the models, but actually shows an increase in rear impacts with LED for 9 of the 17 make-models that switched to LED.
It was just the favourable results for high-sales vehicles such as the Honda Accord that pulled the overall result to a positive benefit.
NHTSA, NCSA, State Data System, effectiveness, evaluation, statistical analysis, automotive lighting, centre high mounted stop lamp, CHMSL, rear impact, crash avoidance, stop lamps
None of these 17 make-models is a “clean” switch pair that shifted to LED without changing anything else. All of the switch pairs shifted to LED at the same time that they changed the rear-lighting configuration and/or redesigned the vehicle.