Vehicle Occupancy and Crash Risk

Abstract

This study explores the association between vehicle occupancy and a driver's risk of causing a fatal crash, not wearing a seat belt, and using alcohol. The survey population is the set of drivers represented in the Fatal Analysis Reporting System for 1992 to 2002. The independent variables are driver age, driver gender, passenger age, passenger gender, and vehicle occupancy. The outcome variables are whether the driver was at fault in causing the fatal crash, whether the driver wore a seat belt, and whether the driver had used alcohol. For male teenage drivers, driving with teenage passengers correlated with an increased risk of causing a crash. For all female drivers and for male drivers over age 40, passenger presence correlated with a reduced risk of causing a fatal crash. Drivers ages 15 to 30 were less likely to wear a seat belt when passengers were present than when driving solo. Drivers age 50 and older had higher rates of seat belt use when passengers were present. This protective effect of passengers was stronger for male drivers than female drivers, and for male drivers the effect increased by age. Drivers ages 15 to 34 accompanied by passengers were more likely to have consumed alcohol than solo drivers of the same age group. These results offer an interesting perspective for research in the area of driver distraction, and they update current knowledge on older drivers and the role of seat belt and alcohol awareness.