A hybrid optimization algorithm for area traffic control problem

Abstract

For an area traffic control road network subject to equilibrium flows, the maximum possible increase in travel demands is considered while total delays for travellers are minimized with respect to the common cycle time, the starts and durations of green times and the offsets. Using the concept of reserve capacity of signal-controlled junctions, the problem of finding the maximum increase in traffic demands can be formulated as a mathematical program with equilibrium constraints. In this paper, we present a hybrid optimization algorithm to simultaneously solve the maximum increase in travel demands and minimizing total delays of travellers. Numerical computations are made for the values of performance index and the reserve capacity achieved at various sets of initial signal settings on a variety of signal-controlled networks. Encouraging results are obtained when compared with other alternatives.

Keywords:

• transport
• mathematical programming
• optimization
• heuristics
• projected conjugate gradient method

Acknowledgements

The author is grateful for referees’ helpful comments on earlier version and funding from Taiwan National Science Council via Grant NSC-94-2416-H-259-008.