Scheduling Work Zones in Multi-Modal Networks, Phase I: Scheduling Work Zones in Transportation Service Networks

The purpose of this project is to study the optimal scheduling of work zones so that they have minimum negative impact (e.g., travel delay, gas consumption, accidents, etc.) on transport service vehicle flows. In this project, a mixed integer linear programming model is developed to schedule work zones in transportation service (i.e., trucking service) networks. The model schedules lane closures of links that need maintenance in a transportation network. When some lanes of a link are closed, the available capacity of that link is reduced. In the assumed scenarios, based on the available capacities on the links, given origin-destination (OD) flow demands are provided system optimal routing through the network to achieve total minimum flow cost for all the OD pairs. The link flow cost function is piece-wise linear such that regular flow cost is incurred for all the units flowing through the link at free flow while extra congestion cost is incurred for the units exceeding the link’s nominal capacity. The goal is to schedule the work zones, that is, the corresponding lane closures, so that all maintenance work can be completed before a given completion date while the total flow cost over the project period is minimized. An innovative randomized fix-and-optimize (RFO) heuristic is developed to solve the problem efficiently. Various networks are tested for the performance comparison between CPLEX and RFO. It is concluded that the RFO heuristic is able to obtain optimal or near-optimal solutions with much less time than CPLEX. In Phase 2 of the project planned in the next period, Scheduling Work Zones in Commuter Transportation Networks, commuters from their origins to their destinations are included in the work zone scheduling problem.