Study On The Metropolis Road Network Planning Based On Urban Spatial Expansion

With the economic developed rapidly, and the population assembled highly in big cities in our country, the contradiction between traffic demand and supply become more serious day after day. At the same time, many big cities expand their area rapidly and the notion of unit has been strengthen. So how to do the research on the road network planning from the angle of city dynamic development becomes very important to the traffic development in big cities.Firstly, this paper concerns on the research on the relationship between urban road traffic and urban space structures. It analysis the effect of urban road traffic to the urban space structures from the angle of urban conformation evolvement, urban interior differentiation and the density of land use. It also discusses the effect of urban space structures to the road traffic and their relationship from the two sides of traffic demand and supply.Followed by, the paper summarizes the characters of urban space evolvement in ancient, neoteric and modern china, points out the problems in space structures of big cities in our country and indicates its effect to road traffic. The trend of multiplied core and unit development is pushed, the traffic characters in such cities is also discussed.To the scale of road network, firstly, this paper analysis the actuality of our big citees'road network scale from the angle of road network density, road area ratio and road level arrangement. Then, it gives the technique on the prediction of urban traffic generation and distribution to big cities'specialty in our country. It pushes the ways to ensure the road network's total scale of multiplied core and spead cluster cities by the space-time consumption law. It is also an important part to give the ways to ascertain the traffic impact area and to make the traffic demand between units. The way to get the scale of relative road network is educe. At last, this paper gives the suggestion indexes fo urban road network density based on the discussion about the relation between public transport network, traffic signal control system, traffic investment and road network's density.In the course of the study on the road network layout, the paper analysis the basic forms of road network in big cities in our country and compares the character and adaptability firstly. Then ,it discusses the basic forms and points out the spreading form's adaptability to the multiplied core cities. The way to disposal the road network in big cities is rised by the traffic unit divide method,and is optimized by the inherit method based on the unblocked reliability.Finally , the paper sets up the index system on the judgment of urban road network planning in multiplied core cities. The project is judged by the simple matrix law and the process is shown as follows.