Digesting Factors Influencing Construction, Maintenance and Utility Work Zone Traffic Injury Severities

This study digested factors affecting injury severities resulting from traffic crashes along work zones in Tennessee. Utilizing five years of crash data related to construction, maintenance and utility work zones, statistical analysis was conducted to evaluate the risk factors involved with resulting injury severities. The injury severities were grouped into four categories including PDO under $400, PDO over $400, non-incapacitating and incapacitating/fatal. Most of the crashes (57%) were maintenance work zone related, 27% construction related and 16% utility work zone related. About 60% of the work zone related crashes occurred during the day, 68% along the roadway and 23% at intersections. Traffic, environment, roadway, and crash factors were evaluated through statistical modeling using Generalized Ordered Logit Model (GOLM). The GOLM model was used due to its less restrictive ability in estimation compared to parallel line models such as ordinary ordered logit. Increase in traffic volumes, and the number of lanes along work zones were found to decrease the probability of severe injury crashes. Increase in the percentage of trucks and higher posted limits along work zones increases the probability of severe injury crashes.