Study On Evaluation Method And Control Strategy Of Urban Road Traffic Congestion

With the rapid growth of China’s vehicle population, the contradiction between supply and demand of vehicles and roads is increasingly prominent. Meanwhile, the contradiction between the road network and road resources is increasingly obvious. The urban road traffic congestion problem, heart of the contradiction, attracts more public attention. At the same time, urban road traffic congestion is continuously spreading from big cities to medium and small cities. Therefore, researching the evaluation method and control strategy of urban road traffic congestion has social significance and economic significance to ease the current traffic conditions in big cities.Based on the study of the variation law of urban traffic congestion, method of combining qualitative and quantitative research, mathematical modelling and data validation and micro-and macro-analysis is applied to the evaluation of urban traffic congestion. Meanwhile, urban traffic congestion control strategy based on the macroscopic and microscopic evaluation is also been approached. Three tasks are completed.(1) Definition and analysis of formation of urban road traffic congestion, and the proposing and cause analysis of concept of secondary traffic congestion. Through the analysis of the formation mechanism of urban road traffic congestion, the concept of congestion kernel is proposed from the perspective of dynamic processes and defined by state division, including smooth, overcrowded, congested and blocked. The time distribution of traffic congestion and the spatial variation of traffic congestion are analyzed with traffic flow theory and the application of plume model respectively. Finally, the concept of secondary traffic congestion is proposed, and the cause and evolution is analyzed by applying Ant Colony model.(2) The modification and quantization of calculation method of congestion delay coefficient and the construction of analysis model of regional road network service degradation index. Evaluation is done by building model on both micro level and macro level. The definition and calculation method of congestion delay coefficient is discussed. Modified congestion delay coefficient is obtained by modifying related factors, which can be used in evaluating urban traffic congestion from micro level. The concept of regional road network service degradation index is proposed, the regional road network service degradation evaluation model is built, meanwhile, the categories of first-degree service degradation, second-degree degradation, third-degree degradation and fourth-degree degradation are quantized, which can be used for evaluation urban traffic congestion from macro level.(3) Urban traffic congestion control strategy based on macroscopic evaluation and microscopic evaluation. Setting Kunming City as example, the causes of urban traffic congestion are analyzed. Taking people, vehicles, roads, environment in urban road traffic and management control into consideration and based on macroscopic evaluation and microscopic evaluation, the research of urban road traffic congestion control strategy is complemented in the structure of combining optimization of road network, optimization of control and management and traffic information routing coordination fusion technology. Meanwhile, suggestions for urban road traffic congestion environment control strategy and drivers’　code of conduct are also proposed for Kunming City.