Traffic Signal Switching Control Approach Based On Traffic State Control Ability Analysis

With the expansion of the urban area, the increasing demand of outgoing, more and more people are now possessing cars. This affects people’s outgoing, results in traffic jams frequently, and brings in worse traffic pollution. The direct influence reflected on the traffic is oversaturated traffic flow, as well as the traffic normality of transition of several traffic states.Implement of urban traffic control strategy is based on the traffic state, so the judging of traffic state is significant for urban traffic control strategy. However, it is difficult to judge the traffic state because of the fluctuation of the urban traffic. It has become the research point of traffic signal control strategy under different traffic state. In this paper, we start from the judging of the traffic state, study the control strategy of the traffic signal, and finally, an intersection switch control method will be presented based on judging of the state controllability.Firstly, a standard two-phase intersection control model will be built, focusing on the analysis the relationship between phase flow and split. A traffic state judging method using flow-split relationship and queue up-time graph is proposed. Then detailed analysis on multi-phase will be prosed and a traffic state judging method based on comprehensive projection will be presented. Furthermore, based on the dimensions determination and decomposition, projection and inverse projection, the relationship between the multi-phase intersection control flow and split can be transformed to3D coordinates, accomplishing the regional assignment of traffic state and the judgment of the state.Secondly, the oversaturated intersection controllability will be considered. The relationship between traffic capacity and the remaining queue will be analyzed, then supply rate and excess demand rate will be introduced, and comprehensive results show the control state of the oversaturated intersection changing with time. The parameter will be used to describe the controllability of the intersection. The controllability will be analyzed in detail using traffic wave method.Finally, the influence of the traffic state changing on intersection control strategy will be considered. Besides, combined with the controllability of the intersection, a switchover control method based on the control state along with the switchover control strategy will be presented. Under this rule, for "controllable state" designed intersection stationary phase sequence queuing emptied strategy with maximum time constraints, for the "uncontrollable state" designed intersection of each phase of the total minimize queuing of objective function genetic algorithm optimization strategy.Simulation examples has shown the method is feasible and effective.