Ecological Characteristics Of Traffic Modes And Structure Optimization In Urban Passenger Transportation

Rapidly economic development and urbanized trend boom up traffic demand. Problems such as traffic jams and low efficiency of traffic system are getting more severe, and environmental issues resulted by traffic system arise, including energy consumption, environmental pollution and land resource occupation.Most of the consumed energy is not renewable. The increasing energy consumption brings great incontinences to urban sustainable development. The accumulating pollutants and noises, produced by the traffic system, deteriorate people's health. The expansion of traffic system occupies valuable land resource and public landscape, which are unfavorable to the city's sustainable development and the environment.Urban passenger transport is the major subject of urban transport, which could be influenced by a lot of factors including land-use types, facility arrangement, traffic status, etc..Different transport mode shares a different passenger-transport requirement, so the scale of traffic different, and bring the difference of urban eco-environment. In this thesis, urban passenger trasnport is divided into four modes: rail, car, bus and slow-mode transport, and from eco-environment perspective, the optimization of mode-split will be evaluated.Bachground of the traffic jams and eco-environment descendants, the planning and building of urban passenger traffic system has a broad development on the theory and practice. For the moment,experts at home and abroad are mainly concerned about the contradiction between urban traffic demand and the supply conditions of traffic facilities, therefore,the urban ecological traffic system is still on the stage of concept exploration and qualitative analysis. This paper set off the urban passenger traffic system to rail transit, car traffic, normal public traffic and slow traffic, then research the passenger traffic structure optimization and evaluation from an ecological perspective.How to use multiobjective optimization problem, one side satisfying the traffic demand, the other one, reduce the damage to the landscape, optimize the passenger trsffic structure, to full play the facilitatory function of the best ecological advantage one. This way is not only an essential factor in the construction of cities'eco-friendly traffic system, but also an inevitable trend of the urban traffic future development.This paper is based on one of the corpus research of the key projects of the"Eleventh Five-year Plan"national science and technology support plan titled"Research on the Key Technology of Urban Integrated Traffic System Planning and Evaluation". In order to reduce the ecological impact of urban traffic system, we systematacially analyzed the ecological impact and ecological characteristics of all sorts of urban traffic modes, thus we proposed a traffic structure optimization model based on ecological and utility properties as well as ecology comprehensive evaluation method. It will have great theoretical and practical significance on the planning and construction of urban ecological traffic system.The connotation of urban ecological traffic system we summed up is used to reduce the traffic system of energy consumption, air and noise pollution and land resources occupation on condition of meeting the basic urban traffic demand. We defined several normal transportation modes in the research and quantitatively analyzed the ecological measure gauge of different transportation modes. By introducing the definition of ecological indexes, and study the calculation methods, further analysis of urban traffic modes of the ecological characteristics were carried out.We analyzed three major types: the passenger traffic facility scale, service levels, and economic cost, including ten indexes. Then proposed the utility index of passenger traffic structure, and researched the model with the methoud. We analyzed the ecological optimization goal for the urban traffic structure, which is to minimize the ecological impact of the overall urban traffic system and to maximize the traffic utility, we constructed a multi-objective ecological optimization function for the urban traffic structure. Urban traffic demand, road resources occupation, travel time, energy consumption and environmental capacity and limit facilities development level are chosen as constraint conditions of the optimization model. Algorithm of the model is also given in this paper.Basic train of thought and theoretical framework of the comprehensive evaluation on urban traffic structure was put forward. Ecology comprehensive evaluation system was constructed and evaluation index was screening and quantified. Based on the extenics theory, we put forward a fuzzy hierarchy comprehensive evaluation method about urban traffic structure. And the grading evaluation standards of ecological degree on urban traffic structure were proposed.According to the combined conglomeration structure and planning traffic structure in core region of Dalian, we researched the ecology comprehensive evaluation. Taking use of the urban traffic structure ecologically optimization model established in this thesis, passenger traffic structure is optimized, based on the current mater planning, population scale and road resources.. Comparing the charactors of passenger transport system pro-model optimization with the charactors pre-model, the results show that the the passenger transport mode-split which suggested by the model is better than the planned passenger transport mode-split especially in enviroment aspect, and meanwhile it satisfies the travel demand and sustainable transport development.