The influence of passengers on older drivers involved in fatal crashes.

The authors examined if the presence of passengers affects the risk of making unsafe actions among older drivers, and determined what specific types of unsafe actions may be affected (positively or adversely) by the presence of passengers. They used 1975 to 1998 data from the U.S. Fatality Analysis Reporting System (FARS); unsafe actions were based on driver-related factors. The authors calculated the odds ratio (OR) of making unsafe driving actions in the presence of passengers compared to situations where drivers were alone. In general, the presence of passengers was beneficial to older drivers (e.g., for drivers aged 65 to 79 with four or more passengers, OR = 0.73 [99% Confidence interval[CI] = 0.61, 0.86. For drivers aged 65 to 79, the presence of passengers was associated with a reduced risk of some unsafe actions (e.g., driving the wrong way, OR = 0.37 [95% CI = 0.30, 0.46]) but a higher risk of other actions (e.g., ignoring signs/warnings/right of way, OR = 1.18 [95% CI = 1.15, 1.22]). These findings are discussed in the context of strategies to maximize safe driving in older adults.