Planning Design Method Of Hilly Cities Bypass Network

Facing the challenge brought by rapid increase in expansion of city space and motorization level,recently a certain progress has been made on city road construction to solve the problem caused by inadequate traffic ability,which has restricted the economy and society development of the city,however some mechanical applications also appeared during the process.Especially in planning the bypass network of city in foothill,due to lacking theoretical research and regional standard,blindly copying the construction experiences of city in plains would result in trunk road during the process of road improving and expanding,the regional cultural marks would fade and the traditional community would also be broken;Characteristics of foothill terrain would be destroyed during the process of ground surface levelling,resulting a big challenge in environment.Therefore,as for cities in foothill,to summarize a series of targeted method of bypass network planning,lining off the main points of regional bypass planning,and to establish a local standard of bypass construction,are of a great importance for protecting the eco-system in foothill,carrying on regional historic culture and ensuring the safe transportation in cites.Thus,firstly based on analyzing the theoretical research and practical experience of former people,the basic concepts and characteristics of city in foothill as well as the basic definition and regarding specifications of bypass were further clarified,and summarized the essential problem of recent city bypass network construction;Secondly,the fundamental targets and principles of bypass network planning and construction were proposed corresponding to the basic characteristics of city in foothill,meanwhile the planning main points of realizing continuous development and a new method of bypass network planning of city in foothill were also came up with.At last,in the case of Changsha city,based on understanding the urban features,relationship between terrain and roads,maintenance condition of road network and problems existed in bypass planning,a targeted local standard of bypass network construction was put forward;Furthermore,the north of Zuojiatang area in Changsha city was selected as the research object,based on adequately field reconnaissance and document investigation in this area,its bypass network was modified by applying the new concept of bypass construction proposed.The facts that the bypass of city in foothill can achieve an organic combination with terrain and the validity of the new method of bypass network planning in hilly city were both proved by planning practice,solving the problems of,diversity in classification,function and target that traditional bypass network planning method ignores,demands of slow transportation and regional culture protection,and planning only referring to national construction standards without consideration of actual conditions.The article can provide a reference to bypass network planning of other hilly cities.