The objective of this study was to determine the association between passenger presence and risk of fatal crash involvement in relation to driver and passenger age and gender, focusing on the oldest drivers ages 65 and older. Data on US fatal crashes were obtained for 2002-06. Using the quasi-induced exposure methodology, logistic regression analysis was used to predict the odds of fatal crash involvement as a function of driver age and gender as well as passenger age and gender. Results showed that older drivers’ risk of fatal crash involvement was lower with all combinations of passenger age and gender. Risk was reduced even with two or more passengers and for male and female drivers. Effects of passengers on older drivers’ fatal crash risk were greater for male than for female drivers, and effects were stronger at non-intersection than at intersection locations. The authors concluded that older drivers’ crash risk is lower with every combination of passenger age group and gender. However, it is unclear whether the presence of passengers lowers older driver crash risk or whether safer drivers tend to ride with passengers. (Author/publisher)
Abstract