Travel Modal Spilt Model Based On Dominant Distance And Software Design

With the acceleration of urbanization in China,the level of city motorization is rising accordingly.Many big cities have begun a large-scale campaign in rail transit construction,and electric bikes have also experienced a rapid development.As the urban traffic system of China is more and more diverse,the traffic structure is undergoing profound changes,thus,the sharing rate of all the traffic modes directly determines the operation efficiency of the overall transportation system.However,the distribution of travel distance of residents is not uniform,and each traffic mode also has their own special advantage in travel distance.Therefore,there is a strong need to reconsider a t macro travel split model based on the special advantage travel distance to guide the engineering practice of urban traffic planning.Based on the National Natural Science Fund Project(51338003,51378120),we focused on the reality of our urban traffic development and the requirement of the engineering practice,and firstly used Nanjing as an example.The travel distance distribution database was established by excavating of the whole residents travel database.Moreover,the features of the travel distance distribution of all the travel modes was qualitatively analized.Based on the analysis of residents' trip distance distribution,we introduced the advantage of travel distance factor,and analized the physical process of a trip,then a abstract mathematical modeling of travel distance distribution was established.Then,the the calibration parameters of the travel distance distribution function was solved by the least square method.Compared with the electronic cloud model,the applicability of the function is better.Based on this function,this paper constructs a basic model of mode split based on the special advantage travel distance.After the analysis of a typical trip process,the generalized travel cost function was completed from two aspects of travelers and transportation decision makers.A nonlinear optimization model to minimize the total travel costs was solved by the particle swarm algorithm,thus,the parameter optimization of travel split model based on the special advantage travel distance was done.Finally,based on the improved travel split model,Visual C++ and Qt were mixed programming,the professional module with the functions to calculate the mode split results under the current situation,travelers' and decision makers'perspective,and decompose the travel demond OD matrix with specific targets was established successfully on the professional traffic analysis platform——TranStar.By combination of the computer software and the practical urban travel mode split model provided by this paper,different transportation policies described by different generalized travel costs can influence the parameters of the model,and then change the urban traffic structure,based on this,a basic tool for the quantitative analysis of urban traffic policies is produced and will make sense in further practice.