A Study On Intelligent Control Method For Urban Traffic

Traffic is the economic heart of a city. It plays an important role in the development of urban economy and the improvement of the situation of people's life. As the direction of the 21th century transportation system, Intelligent Traffic System (ITS) is widely researched by the specialists and scholars of many countries in the world, and it is the essential way of eliminating congestion and improving the utilization of roads.Intersection is the position for the traffic flow to influx and distribute. Optimizing the configuration for crossroad traffic lights is one of the most important parts in ITS. Traffic signal control for a single intersection is the base of Urban Traffic Traffic Control System. In this dissertation, we put forward an optimal algorithm based on the combination of the modeling of signal light and the computer simulation technology. And this method will alleviate the congestion effectively.The optimal design for crossroad traffic lights is the emphasis of our research in this dissertation. The primary target is to provide an optimal method for crossroad traffic lights. This dissertation proposes a method by making use of the space and time furthest in order to reduce the average delay-time, and also puts forward an optimal algorithm named double-cycle in multi-phase signal control. On this basis, we study on the optimal algorithm about signal lights of adjoining intersections. Furthermore, we design a software package to implement our algorithm. This software package can calculate an optimal result of signal timings based on the input of the traffic flow and saturated flow of each road. We also connect this software with intersection microcosmic simulation system. During the course of simulation, the input parameter is the detector data of the road, which is provided by the simulation system and the output is the result of timing. Then we implement the real-time control of the signal lights timing.To sum up, the primarily work that we discussed in this dissertation includes:1. The Optimal design for crossroad traffic lights. Based on the historical data of traffic flow, we propose a mathematical model about intelligent traffic, calculate signal light cycle time and split by this model, and put forward the method to control the signal timing of intersection by using the double-cycle method.2. Global optimal design for signal lights at central intersection and four adjoining intersections. By controlling the offsets between the junctions, the vehicles will fall across green time when they arrive at the central intersection. In this way, traffic delay will be reduced. Another work is to control the cycle time and split of each intersection.3. Real-time adaptive traffic signal control for single intersection. We connect timing software with traffic microcosmic simulation system in order to realize real-time control on signal lights.In addition, this dissertation also researches elementarily on urban linear traffic control and area traffic control and it introduces some methods about linear and area traffic control currently. In future, we will also seek for the optimal algorithm about linear and area traffic control.