A work zone is a selection on an urban highway that is closed for road construction or utility maintenance. Single-lane closures on two-lane highways require a suitable signal control system for managing the two-way traffic. The problem becomes more complicated if there are two closely spaced work zones in which the upstream and downstream traffic signals must be well co-ordinated. Without proper control, vehicle queues may be developed in between the work zones and heavy delays may be induced. Traditionally, vehicle queues have been represented by numerical figures without consideration of the actual space concept and modelled using the cell transmission model (CTM) that encapsulates the fundamental dynamics. Total delay in the highway system is adopted as the objective for optimisation. The problem is formulated as a Binary-Mixed-Interger-Linear-Program (BMILP), and solved by standard branch-and-bound techniques. A fixed length two-lane highway with various work zone configurations is given as a numerical example for demonstrating the applicability of the proposed design method. (A) Reprinted with permission from Elsevier. For the covering abstract see ITRD E134766.
Abstract