Signal Timing Optimization Of Urban Street Intersection Based On Reducing Vehicle Pollutant Emissions

ABSTRACT:After entering21st century, cities in our country develop rapidly, the traffic demand of citizens has increased year by year, and the private car ownership reveals a trend of dramatic increase. As a result, the urban transportation system is becoming more complex, and the urban traffic has become a big energy consumer. Meanwhile, motor vehicle exhaust emission caused by environmental pollution is becoming more and more serious and influence people’s standard living. Therefore, it is necessary that considering from an angle of sustainable development, study on traffic energy consumption and pollutant emissions, analyze its influencing factors and seeking energy-saving breakthroughs.As the intersection is the key point of urban road, it is the main cause of the road congestion and the bottleneck of urban road traffic system. There are so many ways to improve the operating efficiency, in which signal timing is one of the most direct and effective way. Therefore, there is important theoretic value and practical meaning to study urban road signal timing. In this dissertation, it takes signal control optimization of urban street intersection base on vehicle pollutant emissions assessment as the research object, and selects the delay, number of stops as the indexes of measuring timing scheme to establish the model of the urban intersection signal timing optimization. The improved genetic algorithm is used to solve the model, and the vehicle exhaust emission measurement platform is established to evaluate the vehicle pollutant emissions.Based on the existed research results, this dissertation mainly takes the following research work:1. This paper analyzes the base type, parameter and the main evaluation index of the urban signal control and summarizes the development of the urban signal control. Meanwhile, the artificial intelligence and the vehicle emission are considered in the traffic signal control2. VISSIM microscopic traffic simulation model and the pollutants discharge model based on the distribution of VSP is adopted to build the platform of vehicle exhaust emission measurement. Based on VISSIM model output data to obtain the average vehicle delay and parking rate. Meanwhile, vehicle running real-time data from VISSIM will be combined with the pollutants discharge model based on the distribution of VSP to calculate the vehicle emission in the urban intersection.3. Based on analyzing the urban intersection traffic signal control conditions and way, clearing the optimization object and the main optimization parameter, the model of the urban intersection signal timing optimization to be established. On the basis of the basic genetic algorithm to improve the choose, crossover and mutation strategy to establish the improved genetic algorithm which is used to solve and analysis the optimization model.4. Select the actual road network as the signal control intersection research object. On the basis of the actual traffic investigation, structure the intersection microscopic simulation platform, run the algorithm procedures of the design in this paper and the results are detailed analysis and summary. And then, This paper analyzes the situation of flow change and parameter change.