It is indisputable that the vast majority of drivers and carriers would be compliant with a speed-limiter requirement and that it would generate substantial benefits, even if a small percentage of drivers and carriers did not comply.
Opponents also claim that speed limiters promote unsafe speed differentials between cars and trucks, and that requiring them will offset any safety benefits. However, the aforementioned FMCSA research refuted this assertion soundly by noting that domain research on the potential downside of speed deviations among vehicles that could occur because of the interaction of vehicles equipped with speed limiters and those without them seemed far outweighed by the significant safety benefits associated with the reduction in absolute speed afforded by speed limiters.
Given the certain benefits of speed limiters and the minimal cost of setting them, DOT should make this initiative a top priority. Speeding is a more significant factor in truck crashes than any other. As such, it deserves a corresponding degree of attention and certainly more than other DOT initiatives with benefits that are less certain or substantial.