Research on the Safety Impacts of Speed Limiter Device Installations on Commercial Motor Vehicles: Phase II

The key take-away from this research, the largest study of its kind to use real-world data (more than 100,000 trucks), is that speed limiters played a statistically significant role in “speed limiter-relevant” crash reductions.
Furthermore, while historical research legitimately questioned whether “safety culture” could be a confounding variable in previous analyses, this study found no statistically significant difference in overall crash rates between speed-governed fleets and non-governed fleets.  Consequently, “safety culture” did not play a role in overall crash reductions when speed limiters are controlled for.