Observed relationships between driver and passenger restraint use in the front and rear seats.

OBJECTIVE: Seat belt usage has increased substantially since the 1960s, yet driver use continues to affect passenger usage. Recent observational restraint use findings for Maryland will examine the relationship between driver and passenger usage, including adults and children in the rear seat. METHODS: Analyses were based on observational front and rear seat studies administered in parallel from 2016 to 2019. A statistically rigorous front seat project yielded weighted results among drivers and outboard passengers. A study of adults and children in the rear seat was based on a convenience sample of vehicles. Restraint usage results were presented as frequencies and proportions among occupants with known belt use, along with the 95% confidence interval for overall rates. RESULTS: Overall restraint usage rates averaged 90.9% in the front seat study and 81.1% in the rear seat sample. In vehicles with two front seat occupants and a belted driver, the proportion of belted passengers averaged 93.0% over four years. However, among unbelted drivers, only 41.6% of passengers were belted on average. In the rear seat study, an average of 82.7% were belted in vehicles driven by a restrained driver, differing for children (92.0%) versus adults (70.4%). Analysis of vehicles with an unbelted driver revealed an average of 45.0% of belted rear seat occupants, with a considerable difference for children (65.0%) compared with adults (21.0%). CONCLUSIONS: Observational seat belt studies in Maryland in recent years have shown that, despite overall rates above 80%, passenger use in both the front and rear seats is associated with driver restraint use.