A Preliminary Investigation into the Safety-Critical Event Risk of Aging Commercial Motor Vehicle Drivers

The majority of research into age-related declines in driving performance has concentrated on light vehicle, non-commercial drivers. However, the aging of the commercial motor vehicle (CMV) workforce raises a number of important questions regarding the potential impact of age-related declines in perceptual, cognitive, and psychomotor performance on the ability to safely operate a CMV. The current study offers a secondary analysis of four existing naturalistic truck driving studies examining the safety-critical event risk of younger CMV drivers (30 to 40 years old) versus older drivers (50+ years old). Results for the initial analysis show that the younger and older driver groups did not differ significantly from each other, with the exception that the younger drivers had 2.4 times the odds of being involved in an at-fault near-crash. Additional comparisons were also conducted between younger drivers (30 to 40 years old), older drivers (50 to 64 years old), and the oldest drivers (65 years old or older), though the sample size of six drivers for the oldest drivers group was small. Results for the second analysis indicate that the SCE, at-fault SCE, near-crash, and crash-relevant conflict rates did not differ significantly between the younger, older, and oldest driver groups. Crash rates also did not differ significantly, though this needs to be interpreted with caution due to the small number of crashes in the final data set. In general, the results provide evidence that older (50 to 64 years old) drivers are as safe behind the wheel as their younger counterparts. Due to the small sample size for the oldest driver group (65+ years old), the preliminary impression that they are as safe as the other two groups cannot be statistically tested or confirmed.