Older-driver population is increasing rapidly and they tend to involve inmore severe crashes when compared to other driver age groups. Further, many past researchers have found that older-driver injury severity was high in crashes on rural roads as compared to urban roads. Thus, identificationof various contributing factors for older-driver involved crashes on different road types is important to improve older-driver safety. In this analysis, a statistical modeling technique was used to identify factors contributing to older-driver injury severity. Two different models were developed for rural and urban situations using ordered probit modeling technique, considering all possible explanatory variables under various characteristics. Based on the analysis, it was found that males had a tendency for lower injury severity both on urban and rural roads compared to females. Seat belt usage and presence of passengers led to a reduction in injury severity among older drivers. Single-vehicle crashes were more severe on urban roads causing higher injury severity for older drivers; but on rural roads, the number of vehicles involved in crashes was not contributing to severity. Off-road-type crashes and crashes occurring during off-peak times in rural areas had a tendency to cause more severe injuries to older drivers. In general, speed, gender, presence of passengers, road type, street lighting conditions, etc. were found to be important parameters affecting injuryseverity of older drivers both on rural and urban roads.
Abstract