Vehicle Familiarity and Relative Risk of Fatal Crash Involvement

Abstract

Lack of familiarity with a vehicle has been associated with increased crash risk independent of overall driving experience (Perel, 1983). This may pose an underappreciated safety risk in the context of complex and rapidly evolving driver assistance technologies and driver-vehicle interfaces, especially when people drive newly purchased, rented, or borrowed vehicles. The current study estimates the relationship between vehicle ownership and responsibility for crashes using data from 231,056 drivers involved in fatal crashes in the United States in years 2008-2017. A driver was considered responsible for the crash if police indicated that the driver’s pre-crash actions contributed to the occurrence of the crash, and non-responsible otherwise. Driver-, vehicle-, and roadway factors that might also influence crash risk were controlled using logistic regression. Drivers of vehicles registered to another person and drivers of rental vehicles had 1.15 and 1.20 times the odds of responsibility for their crashes, respectively, compared with drivers of their own vehicles. If non-responsible drivers approximate a random sample of all drivers present at the times and places of fatal crashes, these results approximate ratios of responsible involvement in fatal crashes per unit of driving exposure. While ownership is an imperfect proxy for familiarity and may be associated with crash risk by other mechanisms unrelated to familiarity, results are consistent with the hypothesis that drivers of unfamiliar vehicles experience elevated crash risk.