Effect of enhanced seat belt reminders on driver fatality risk.

OBJECTIVE Enhanced seat belt reminders in automobiles have been shown to increase belt use rates by approximately 3 percentage points. The objective of this study was to estimate the effect of enhanced seat belt reminders on driver fatality risk. METHOD Data included all passenger vehicle driver deaths and vehicle registration counts in the United States for calendar years 2000-2007. Driver fatality rates per vehicle registration per year were compared for otherwise identical vehicle models with and without enhanced seat belt reminders. RESULTS Driver fatality rates were 6% lower for vehicles with enhanced seat belt reminders compared with vehicles without enhanced belt reminders. After adjusting for vehicle age differences, the estimated effect of enhanced belt reminders on driver fatality risk ranged from a 9% reduction for General Motors vehicles to a 2% increase for Honda vehicles. Combining all manufacturers, enhanced belt reminders reduced fatality risk by approximately 2%. Although not statistically significant, the 2% reduction in fatality risk agrees with what should be expected from a 3 percentage point increase in seat belt use rates. CONCLUSIONS Enhanced seat belt reminders have raised driver belt use rates and reduced fatality rates, but more aggressive systems may be needed for some drivers. It can be inferred that nonfatal injury rates also have been reduced. IMPACT ON INDUSTRY Manufacturers should be encouraged to put enhanced seat belt reminders on all vehicles as soon as possible.