Assessment of vehicle age as a contributor to temporal shifts in single-vehicle driver injury severities

Vehicle age plays a crucial role in crash occurrence and occupant injury severity, with older vehicles historically associated with more severe injury outcomes compared to newer models. This study investigates the temporal instability of specific injury-contributing factors for single-vehicle, single-occupant crashes involving vehicles equal or less than 3 years old at the time of the crash, using data from Alabama’s Critical Analysis Reporting Environment (CARE) system. The analysis spans four time points: 2010, 2014, 2018, and 2022. Preliminary data analysis indicates a reduction in new vehicle severe injury crashes from 7.25% in 2010 to 4.05% in 2022. Random parameters multinomial logit models with heterogeneity in means were developed to identify crash factors significantly related to injury outcomes. Key findings highlight the consistent trend of higher severity crashes in which drivers fail to use a seatbelt and airbags are deployed. However, there was a notable decrease in severe injuries for 3-year-old vehicles involved in crashes in 2022 compared to previous years. Model results revealed that this benefit is particularly evident in the reduced likelihood of severe injury among drivers older than 65 years where airbags were deployed over the years, except for 2010. The study indicates the importance of advancements in vehicle technology in enhancing occupant safety. It also emphasizes the need for ongoing research into driver behavior, road conditions, and the evolution of safety standards to fully leverage these technological improvements. The findings suggest that continuous updates to driver education and awareness programs are essential to reflect new technologies and changing driving environments, ensuring drivers can effectively utilize advanced safety features.