Factors Affecting Common Vehicle-to-Vehicle Collision Types

The number of older drivers (65+ years old) is increasing as a result of the baby boom generation reaching retirement age and an increase in driver's license holders among the elderly. The types of collisions incurred by older drivers are compared with those of drivers 30 to 60 years old in vehicle-to-vehicle collisions using the General Estimates System 2002–2003 sampling of reported motor vehicle collisions compiled by the NHTSA National Center for Statistics and Analysis. Multinomial logit vehicle-to-vehicle collision outcome models that account for driver, vehicle, roadway, environmental, and temporal characteristics were created for drivers age 65 and older and a comparison group of drivers 30 to 60 years old. The older drivers are significantly more prone to collisions related to vehicle turning and intersecting paths—particularly at signalized intersections—than are 30-to-60-year-old drivers. As a factor, age is elastic for same-direction and vehicle-turning crashes. Probability decreases with age for same-direction collision types but increases with age for vehicle-turning collision types, this indicates that difficulty with intersections increases for older drivers. Within the 30-to-60-year-old group, age was not significant. The results support findings of previous studies that older drivers tend to avoid driving in suboptimal conditions. The conclusions provide insight into roadway improvements that require priority for research and funding to make driving easier and safer for road users in general and older drivers in particular.