With the implementation of new urbanization strategy of our country, the new urban district has showed a rapidly developing trend in our country, in order to promote the service ability and service quality of transportation infrastructure in new urban district, many domestic new urban districts plan to construct the modern tram system. However, because of inadequate knowledge on the technical characteristics and key operating indicators of the modern tram, and due to lacking of guidance method on modern tram network planning, so the modern tram layout planning is not suitable for the master plan and objective condition of new urban district. The operating modern tram system are facing serious problems of insufficient passenger flow and function. By studying the planning method and key techniques of network passenger flow demand analysis, network scale measurement, network generation, and network evaluation and decision making, forming the network planning system, it will be beneficial for improving the scientificity and rationality of network planning, which will promote the sustainable and healthy developing of the modern tram system in new urban district.
This paper study on structure and basic characteristics of urban public transport system, it clarifies that the modern tram network planning in new urban district should focus on how to deal with the relationship with land use, supply and demand balance, public transport system and short-term demand and long-term development. Combining with technology characteristics of the modern tram system, it has deeply studied the running characteristics of the modern tram system in this paper, basing the foundation for the research on the planning method of the modern tram network.
From four aspects of Transit Oriented Development (TOD), Bus priority, Intensive development and Low-carbon green development, it has researched the development mechanism of the modern tram network in new urban district in this paper. Through analyzing the adaptability in new urban district of modern tram, it clarifies the functional orientation of modern tram in multi-mode and multi-level public transport system.
Based on the traditional "four-stage method", it has studied the method of model selection and parameter choice in passenger flow forecast of tram network in this paper, and proposed that trip generation forecast should be based on the characteristics and development law of new urban district, and then adjust and re-calibrate the model parameters, and for a particular active district, the core area coefficient should also be considered; trip distribution forecast should be modelled separately according to differences between internal and external transport links, and used overlapping demand theory to make network overlay; trip mode division should carry out utility parameter calibration by fully considering the appropriate travel distance, travel speed, transport capacity and other characteristics of the modern tram system; network distribution should be combined with stepwise development of new urban district to build the distribution network model step by step, and add consideration of ground intersection signal delay.
By the analysis of main factors affecting modern tram network scale in new urban district, it has proposes the network scale calculation method based on passenger flow demand, network coverage and geometric analysis; then studied the coupling mechanism of new urban district spatial structure and modern tram network, the evolution mechanism of modern tram network, on the basis of the basic form analysis of modern tram network, and it has proposed the select method of modern tram network layout shape in new urban district. In this paper, “face, line, point" factor analysis method is applied to study the control factors of network generation and structure the initial network; virtual path generation method based on traffic zone important degree and entity path generation method based on the hubs important degree is applied to conduct the initial network improvement; KSP shortest path algorithm is used to structure the network optimal model of modern tram network and provide the technical support for the new urban district modern tram network generation and optimization.
In order to evaluate scientifically the modern tram network planning effect in new urban district, it has established the assessing objectives, criteria and an indicator system which can reflect the good and bad degree of network planning, and by analyzing the weight of these indicators, fuzzy comprehensive evaluation model is adopted for evaluating the network planning programs. Through the adoption of multi-objective decision making of the ideal point model (TOPSIS), build standardized decision matrix to determine the modern tram planning line network implementation scheme for the modern tram will provide a scientific basis for planning line network implementation.
Taking the modern tram network planning of Nanjing Hexi New District as an application example, using the network planning method and technology proposed in this paper, it has systematically studied the functional orientation, application mode, passenger flow demand feature, network distribution and network evaluation and optimization of Hexi New District modern tram network, and furtherly validated the network planning methodology as proposed in this paper.