An Approximate Dynamic Programming Strategy for Responsive Traffic Signal Control

This paper proposes an approximate dynamic programming strategy for responsive traffic signal control. It is the first attempt that optimizes signal control objective dynamically through adaptive approximation of value function. The proposed value function approximation is separable and exogenous factor independent. The algorithm updates the approximated value function progressively in operation, while preserving the structural property of the control problem. The convergence and performance of the algorithm have been tested in a range of experiments. It has been concluded that the new strategy is as good as the best existing control strategies while being efficient and simple in computation. It also has the potential of being extended to multi-phase signal control at isolate junction and to decentralized network operation