Signal Timing Optimization Model Based On The Coordination Control Between Traffic Guidance And Bus Priority

ABSTRACT:With the rapid development of society and economy, the motor vehicles owned continue to hit a new high. The large number of motor vehicles not only leads to serious traffic congestion, but also causes serious air pollution and noise pollution. To effectively solve the problem of urban traffic and to protect the environment, we must insist the "bus priority" strategy and the "green transportation" strategy under the constraints of limited resources. By using the advanced science and technology and management method, we can solve the traffic problems more effectively. Therefore, the paper aims to achieve the "bus priorities" and "green transportation" integrated with traffic guidance on the basis of the advanced achievements issued at home and abroad. The main contents of this thesis include:1.A double-objective bus priority signal timing model is designed in this paper which includes emission factors and delay factors. The target function is composed by average delay and average emission per people. The corresponding constraints are also constructed.2. A synergistic mechanism analysis has been done among bus priority strategies, traffic guidance, signal timing control. Then the utility function, the compensation coefficient and rules of path selection are put forward. Based on the above researches, a real-time and dynamic traffic flow model is established which can be updated according to the road network conditions.3.The composition and the form of double-ring phase are analyzed in details. By analyzing the traffic flow of each import channel, this paper design a reasonable double-ring phase and then do the signal timing solving.4. The traditional genetic algorithm is improved. If the individual does not meet the constraints, it will be set to death directly. We also build a fitness function, use saturation degree as punishment function and stringently protect the excellence in every generation. By using the methods above, the algorithm can achieve the purpose of optimizing the signal cycle and green ratio at the same time.5.The improved genetic algorithm is put into practice to solve the models with different objects. The results are compared with each other.The results show that the coordination model not only can well coordinate the relationship between the delays and the emissions, but also each target can simultaneously achieve more satisfactory effects. The delay calculated by people and the delay calculated by car reduce the rate of4.4%and2.8%. What’s more, double-ring phase model can reduce total vehicle delay22.4%, while emissions can also be controlled within the ideal range, which can be reduced4.1%.