Mountain Urban Expressway Overall Design And Evaluation Research

China has an extensive territory, and cities have different geographical conditions. Plain cities are mainly distributed in central, eastern and coastal regions in our country. Land of these cities is convenient for the centralized development, so layout of land is lumpy. Western cities of our country are the typical mountain cities, where land with good geological condition is chosen to expand and layout presents group structure. Based on this, travel distance of the mountain cities is mainly dominated by middle and long distance. It is thus particularly important to build expressways in mountain cities to improve the efficiency of travel. Expressway layout has effect on the urban transportation and layout of land use. At the present stage, the expressways layout of mountain cities is simply in reference to the ring-ray pattern of the most domestic cities without consideration of the landform and physiognomy. Therefore, it is very important to research and evaluate the general layout of mountain urban expressways.Firstly, this paper comprehensively introduced an overview of research status of expressways in the domestic and overseas and main forms of expressways layout. On the premise of the overall layout of the expressways, this paper analyzed the traffic characteristics of different terrain of the mountain cities and illustrated the importance of expressways especially for some big mountain cities. In this paper, we did planning researches on the expressways from these aspects of layout, cross section setting and connection with other urban roads. Based on the analysis of the methods of existing fast road layout, we proposed to methods of the overall layout of expressways and described the processes according to the theory of transport location and node importance theory in mountain cities.Secondly, this paper constructed the main indices evaluation system of general layout of expressways of the mountain city, and used the theory of analytic hierarchy process (AHP) to evaluate these indices.Finally, according to the route network process of expressways of mountain city, this paper analyzed the example of fast road project in the central area of Kaili-Majiang. We designed "ten" shaped road network layout for the central area of Kaili-Majiang by evaluating the main indices of layout. The network layout of expressways has been gotten recognition of expert groups and local government and chosen as the road layout scheme in the comprehensive transportation project of the centre city of Kaili-Majiang. After example analysis and verifying the conclusion, it has certain reference significance for expressway design of mountainous cities in our country.