The Research On Model And Method Of Multiple Intersections Signal Control

With the development of China’s social economy, the urban vehicle ownership is growing. In this case, traffic congestion problem has become the social focus. Intersection is the main distribution point for urban traffic system; it’s the key point to solve the traffic congestion. Traffic signal control is the most effective way to manage traffic intersections. Based on the research situation of traffic control at home and abroad, this paper put forward some traffic models and traffic control strategy. The main research contents are as follows:(1) In the paper, the whole intersection delay character under two kinds of left-turn traffic flow organizations, direct left-turn plan and Right-turn-Straight-U-turn(R-S-U) plan, was analyzed. Based on Webster delay model and gap acceptance theory and through mathematical derivation, vehicle average delay models for two kinds of traffic flow organizations and discriminant model left-turn traffic flow organization were constructed, respectively. The model shows that: considering the whole intersection delay as objective, R-S-U plan has more advantages when left-turn traffic flow volume is smaller than a certain threshold; otherwise direct left-turn plan is much more reasonable. Threshold of flow discriminant is relevant to volumes of left-turn traffic flow and opposition-direction traffic flow.(2) Based on the classical traffic steady-state theory, this paper established a delay model that the phase difference of related intersections is the parameter. Experiments show that the calculation process of the model is quick, the error of delay calculation results is small, and can reflect the changed trend of average delay precisely when the phase difference is changing. At the same time, the VISSIM simulation and the proposed model both show that the model is suitable for the adjacent intersection and related intersections signal control plan.(3) In order to ease the situation of traffic congestion in the urban road network, an actuated control based on multi-agent technology approach for intersection group is proposed. The concept of Flow Direction Access Priority and its mathematical model are put forward. For the purposes of responding traffic demand quickly and maximizing utilization rate of space-time resources of road network, a mathematical model is established based on the internal drainage and external control strategy and Flow Direction Ending/Failure Rule, which is the feasible flow direction combination at the every switching duration is determined in this way. The above-mentioned control logic was achieved completely with the VISSIM-COM programming on a typical 3×3 intersections group. The results of the simulations indicate that the proposed model effectively decreases the average delay and the average queue length compared to the fixed timing plan, that is, improves operating efficiency of intersection group significantly.