Optimisation of contraflow operations: Model and algorithm.

There are two problems associated with contraflow operations, namely, the lane configuration problem and the scheduling problem. The former determines the optimal lane reversing scheme for the operation while the latter decides the start time and the duration of contraflow. In this study, both problems are modelled under one bi-level programming model. The upper level problem gives the optimal lane configuration and schedule by minimising the total travel time of the study area, while the lower level is a traffic simulation model that can capture the response of drivers towards the network changes. A hybrid metaheuristic-traffic simulation methodology is suggested to solve the proposed model. An illustrative case study of Singapore arterial network is adopted as an example to test the effectiveness of the proposed model and algorithm. Results show that by considering these problems simultaneously, an overall optimal solution can be obtained compared with solving the problems individually. [ABSTRACT FROM AUTHOR]