As the National Highway System grows older, the increasing number of work zones has been presented to address the growing needs of maintenance and construction. However, the reduced operating speed, narrowed lane width and shoulder clearance, and other construction activities, not only resulted in crashes but also caused excessive delays. In order to understand how actual work zone layouts, traffic conditions, and driver behaviors affect work zone capacity, this study aims to evaluate work zone mobility by utilizing the naturalistic driving study data.
The capacity of different work zone configurations will be determined by the fundamental traffic flow models. In addition, the speed and headway distribution in freeway traffic flow before, during, and after the work zone will be explored to understand driver behaviors in selecting their desired speed and headway when traversing freeway work zones.
Although the freeway work zone capacity methodology proposed in the latest edition of the Highway Capacity Manual has been substantially improved over previous editions, it is still limited by the fact of the macroscopic model, which cannot account for various work zone configurations. The results from the naturalistic driving study data offer a unique opportunity to observe actual driver behaviors negotiating different work zone configurations, which can be utilized to improve the existing work zone planning and capacity analysis tools.
Who can benefit from the finding(s) of this project?
The results of this study could provide Department of Transportations (DOTs) and transportation agencies with a better understanding on how drivers negotiate the freeway work zone area and how work zone layouts, traffic conditions, and driver behaviors affect work zone capacity as well. The state and local agencies can improve their work zone planning and analysis tools based on the research results.