Research On Reasonable Structure And Distance Of Urban Road Network

Urban road transport system is the main part of the city traffic, its traffic constraints is the main cause of the problem. At present, there are many problems at domestic road transport system, and "obscure road function and unreasonable network grade proportion" is the most obvious. But there are many representations about road function and administrative levels and few researches on grade proportion and road space which guarantees road function. Based on the above, this study was supported by National Natural Science Fund Reasonableness "Discriminant and Simulation for Intelligent Hub Traffic Modes Connection of Urban Passenger Transportation" (50778141) . It chiefly focused on road grade proportion and space.This paper analyzes the characteristics of urban road system and discusses the thinking and functions of every classification road classified , it points out that there are many problems in the road system. Road function is the cut-in point of my research, so it is important to look for measurable indexes. It analyses travel distance distribution of urban traffic and road preponderant trip distance at all levels is derived. The rationality of road category structure can be discussed by the equilibrium thought about supply and demand. At last, a new concept of safety reliability is proposed for safety evaluation measure at intersection. Based on uncertainty factor of intersection safety, the paper uses orthogonal method to design experiment, applies traffic software VISSIM to simulation experiment and sets up traffic conflict number model. On this basis, the paper establishes an intersection safety reliability model which takes conflict ratios as the index by clustering method. Determining intersection space (roads space) methodology is proposed by analyzing the relation between intersection space and intersection safety reliability, intersection capacity reliability.