Main Points of Choice of the Urban Road Line1. The overviewAs one of the products of social development and one of the main component elements of modern cities, the urban road has respect to the coordination and sustainable development of cities and sh ows the cities’ potential of economical and cultural development. The original network of urban road needs to be programed and adjusted again , especially owning to the rapid expansion of cities and the great increase of the number of cars in recent years. The urban road is not a seperated object any more, and its development is increasingly restricted by other factors of city develpoement. Therefore, the line-bit choice should show the coordination and integration between roads and the environment. The reasonable line-bits will have a positive impact on the economy,society, environment and people’s life. On the contrary, the unreasonable line-bits will influence the surroundings of them and bring some side effects.2. The comparison and selection of line-bitsWith the increasing importance attached on such issues as sustainable develpoement, environment protection and land usage, the thinking modes of road design should be changed, from only emphasizing the cost of initial construction stage to considering the cost of both construction and operation, only the safety and interest of the users to the feelings of other residents and the public, only the visible terrain and objects on the ground to the construction conditions such as geology, historical relics and mineral resources, only the coordinative design among the roads themselves to the coordinative reseach between roads and their such surroundings as natrue, ecology, society and humanity. The comparison and selection of line-bits means that the designer, in his day-to-day job,compares the different lines in different aspects and chooses the most economical, practical,and reasonable one which also meets the country’s relevent standards and policies. However, the selection is made with the designer’s over all consideration of the economy, cultrue, environment, pedestrian, safety and road-intersection, and under the premise of not having influence on the public’s life and economic develpement.3. The main points.At present, the line selection in the design of urban road is not only a purely technical proof process of the line-bit comparison and selection, but also a process of implementing the pre-planning.At the same time,it needs the respect for natural environment,the adoption of public opinion,the prudence of demolition works and the consideration of economic interests of the parties, especially the protection for water resources and cultural relics. Only the above points having been finished, the selected road line could receive broad supports,reflect the planning intention, promote local economic development, and improve the function of urban road network.3.1. The implementation of the pre-planningThe choice of urban road lines should be based on the reasonable plan of urban land usage and urban road network.And it is necessary to consider both the urban land usage and urban road network. In recent years, with the rapid development of urban construction,the phenomenon that urban planning can not keep up with urban construction frequently appears, which also has led to many reconstruction and waste of resources. How to find a better mode of operation to minimize the losses, is the first issue worthwhile exploring in the urban construction planning. Only having the full knowlegde of pre-planning intention and understanding of the funtion of project planning, can people imlpement the planning better.3.2. Respect for natural environmentAccording to "the report on China's ecological problems ",ecological damage caused by the construction of road transportation and developing of mineral resources has become one of the main reasons for the deterioration of ecological environment, and intends to be more and more serious. General designers are accustomed to "dig roads in mountains and build bridge over waters". This has resulted in that it will take a long time for the completion of infrastructure projects,the large tracts of vegetation and Original topography to recover or not resume, or even resulted in a series of environmental disasters . The awareness which the designers need to establish is that road is a part of the whole environment of its location,so when we select and design the road lines,we should attach importance to the protection of and respect for the environment so as to make the environment better ,but rather damage the surroundings. Therefore, as a responsibile designer,one needs to tirelessly and repeatedly optimize the line programs.Line selection embodies respect for the natural environment at the following points:1.Take up less arable land; keep away the basic protectedfarmland;2.Evaluate on the basis of environment;keep away the sore piont of environment;3.Conform to the topography and geomorphology; reduce the high filling and deep digging.3.4. Prudence of demolition worksAccording to the previous experience on engineering, the problem of removal and compensation is often an important factor influencing theproject advancement. Therefore, we should pay attention to the road line-bit as much as possible to avoid dense building areas and to reduce the cost of demolition and resettlementthe. When we have to demolish some buildings,we should try our best to carry on the country's resettlement subsidy policy, and we need to not only safeguard the lawful rights and interests of the demolition parties, but also guarantee the smooth progress of construction projects. "The Property Law of People's Republic of China " was put in practice on October 1, ter on, the demolition for urban road construction or land development should be considered more carefully.3.5 The consideration of economic interests of the partiesIn the process of selecting road line’s scheme, on the premise of standard meeting, if the alignment of road is bad, its investment is small; if the alignment is good, the investment is large; if the investment is small, its enforceability is poor;if the investment is large, its operability is high. All these make it difficult to set down which one is better. “The Guide for New Concept of Highway Design” which i s compiled by the Ministry of Transportation has proposed to establish a design concept of “the cost of full life-cycle”,that’s to say, the road lines should be intercompared in such stages as construction, maintenance, operation and management,and both the construction cost and operating cost should be taken into account. In addition,we need to carry out the economic analysis in the feasibility study for the road’s construction,and to carry out the analysis in terms of economy and social benefits when comparing the schemes of parts of the road, so that the line-bit and its technical indicators could be settled down by its service level and the benefits for economy and society..3.6 The protection for water resourcesAt present, our country’s intensit y of controlling water pollution is increasing year after year, and people have realized that the seriousness of ecological deterioration caused by water pollution. So when reservoirs, lakes and other water bodies get involved in the process of line selection, we should pay special attention to whether these water bodies are the residents’drinking water sources or not. Because the water on the pavement will cause contamination, direct discharging the above water bodies will damage the water resources and threat the lives of urban residents. Therefore,when setting down the lines,we must give priority to protecting the water resources,set them down at the lower reaches of water bodies or beside the protection line of water resources.Under some special circumstances such as having to build a bridge over the water or set down the line at the upper reaches,we should carry out especial drainage design, make the water on pavement be discharged and disposed seperately ,and arrange the preplans for the accidents caused by the hazardous chemicals,in order to ensure the water safety.3.7. The protection for cultural relicsIf there is a cultural relic in the area going to be used for road constrution or within the demolition site,we have to evaluate the level of the cultural relic according to Law of the People's Republic of China on the Protection of Cultural Relics, decide whether adjust the line-bit or not ,because the cultrual relics can not be randomly dismantled or demolished,and appearance be destroyed. Only with the approval of relevant departments,the licensing authorities can issue the permits for construction or demolition.3.8.Other factorsIn the process of choosing the urban road lines, we may come across some other factors. On that conditon, we must considerate comprehensively and emphasize some point, and select the best line, on the premise that the project is practical, as the recommended line to advance the project .4. ConclusionThe line-bit seems simple, but in fact there are a lot of knowledge storing up in it. Not all the points mentioned above may arise in the process of choosing the urban road lines , but it is likely to encounter more problems that are more complicated.And these problems are always contradictary:if you intend to protect the water resources,the range of demolition may increase;if you try to protect the environment, the investment may raise. Therefore, after so many cpmparisions and various opinions of the natives being taken into account, setting down the final practical program is a hard and complicated process of selecting. as a responsible road designer, we must consider all these factors and choose the best and use it.城市道路线位选择之要点1、概述城市道路是社会发展的产物,是现代城市的重要组成部分,关系到一个城市的协调和可持续发展,也体现出一个城市经济、文化发展的潜力。