Study On The Rational Structure Of Urban Road System

The planning of the road system is the main respect of transportation planning of the city. The road network is the most basic network in the city comprehensive network, other networks often depend on road network, such as public transportation network, rail network, freight transportation network and so on. Function structure of road network must be creating the essential foundation for other networks. The planning of urban road network directly influence the social development of economy, whether every traffic way can coordinate and combine each other, road network arrangement can produce best social economic benefits, people goes out to be convenient, fast, comfortable, economy and security. Reasonable planning of the urban road network will play an important role in improving resident's condition of going out structure, solving city traffic jam, saving land resource, promoting energy-conservation reduce, leading adjustment of the city arrangement and promoting the development of urban economy.The text analyzed the essential feature of road network from three aspects which include arrangement structure, function structure and grade structure of urban road network, and then has described the relationship and importance between them, on this basis, set up the motor vehicle function of distributing by two method, analyze and calculate the suitable distance of every grade road, then thought to use the equilibrium of supply and demand to check network arrangement form and confirm road grades of proportion, finally, in view of the impact on transportation construction by the rail transportation, analyzed the relationship between road transportation and rail transportation, point out the impact on the rational structure of road network by the construction of the rail transportation in the future. The text takes Xi'an as an example, under typical network of road arrangement terms, have further proved the theory puts forward in the article.