Capacity Modeling and Control Optimization for a Two-Lane Highway Lane-Closure Work Zone

Abstract

A two-lane highway lane-closure work zone is a unique work-zone type because of its traffic impact. When one lane of traffic is blocked, it is necessary to implement a traffic control strategy to effectively serve bidirectional traffic. In the sense that the right of way is allocated between two directions sequentially, traffic control at two-lane highway work zones is similar to signalized intersection traffic control. In order to analyze the problem, this study proposes two primary methodologies: (1) mathematical capacity and delay functions based on signalized intersection theory, and (2) a microsimulation model calibrated using field observed data. After fine-tuning the parameters, the mathematical functions were able to estimate delays with reasonable accuracy. The models developed in this study were applied in the optimization of a two-lane highway lane-closure work-zone control management plan. The resultant delay-capacity diagrams indicate that for pretimed control, roadway capacity should be maintained at a slightly higher level than the traffic demand, whereas the dynamic traffic control scheme is able to achieve lower delay results than the optimal pretimed signal control.