Investigating Factors Contributing to Injury Severity in Work Zone Rear-End Crashes

Egypt's National Road Project is a large infrastructure project which presently aims to upgrade 2500 kilometers of road networks as well as construct 4000 kilometers of new roads to meet today's need. Increasing the amount of highway construction results in a significant increase in the number of work zones and therefore a rise in more hazardous conditions. This paper aims to investigate and identify the significant contributing factors for work zone rear-end crash severity, by applying a factor analysis method and an ordered probit model to analyze data on the Egyptian long-term highway work zone projects during the period of 2010 to 2016. The main and common factors which influence crashes are identified by factor analysis, while the probit model is developed based on the scores of factor analysis to examine how those factors contribute to crashes. The results show that the most influential factors which contribute to crashes are gender, road character, number of lane closures, and age. Furthermore, five common factors significantly affect the severity of work zone rear-end crashes, whose accumulated contribution percentage is 65.92%.