Analysis of Work-Zone Crashes Using the Ordered Probit Model with Factor Analysis in Egypt

Work-zones, due to their nature, are predisposed to hazardous situations. This is a consequence of conducting construction work within the vicinity of, or near, vehicular traffic. The exposure to danger underscores the need for proper understanding of the occurrence of work-zone crashes, as well as the risk factors associated with them. This paper aims mainly to develop a hybrid approach that combines a factor analysis method and an ordered probit model to carry out a comprehensive analysis of work-zone crashes. The paper presents an analysis of work-zone data crashes from 2010 to 2015 that occurred in Egyptian long-term highway maintenance and rehabilitation projects. Factor analysis is used to identify the main and common factors that influence work-zone crashes and to calculate the weight of every factor. The ordered probit model is developed, based on the results of factor analysis scores, to examine the contribution of common factors in the severity of work-zones. The most influential factors that have contributed to work-zone crashes are weather condition, number of lane closures, type of surface construction, road character, day of week, and so forth. In addition, the results indicated that four common factors are significantly affecting the severity of work-zone crashes in Egypt.