Optimal Sequences of Fixed Time Signal Plans

Most area traffic control systems use fixed-time signal plans because these strategies are efficient and easy to implement. Fixed-time plans are calculated for a number of characteristic traffic situations and are implemented when such a situation arises. Taking into account the fact that changing from one plan to another causes an increase in delay for the vehicles in the network, in this paper a method for determining optimal sequences of signal plans is developed. The optimal sequence is determined using dynamic programming methods and optimal plans for characteristic situations are calculated using the TRANSYT program. The objective function is the total delay in the network during a chosen period.