Studies On The Urban Public Transit Network Accessibility Based On TransCAD

With the rapid development of our country’s economy and society, the process ofurbanization scale population centralization and urban mobilization are speeding up. Asresults of urban disorder development, traffic issues, such as traffic congestion, automobileexhaust pollution etc, outbreak in large and medium-sized cities. The traditionalmobility-oriented traffic development idea is unable to relieve the more severe traffic issuesthan ever before and cannot meet the increasing demand of resident travel. At the same time,giving priority to public transport development has become people’s consensus. Thedemonstration project of “transit metropolis” has been promoted all the country. Under thebackground above, studying urban public transit network accessibility will help to enhancethe attraction of urban public transport trips, relieve the urban traffic issues and meet residenttravel demand for high efficiency and high accessibility.The evaluation system of urban public transit network accessibility is proposed based onthe concept of accessibility and by analyzing the research condition at home and abroad,dissecting the influenced factors of the urban public transit network accessibility and studyingcurrent accessibility model. With comprehensively considering temporarily-Spatiallyconstrained model, topological metrics method, the cumulative opportunity model and so on,the evaluation indexes system of urban public transit network accessibility is built at macro,medium and micro levels and the mathematical model is put forward for each index. Themodel can be applied for comprehensively and multi-level evaluating urban public transitnetwork accessibility, recognizing its accessibility levels and discovering the existed defectsand deficiencies in this system.Urban public transit route system is constructed by using the TransCAD software. Urbanpublic transit network database is designed and it consists of the spatial geography databaseand the public transit route system database. According to public transit characteristics,generalized cost model of travel path is built and the optimal path judging standard is set upconsidering transfer times and trip distance. The optimal path calculation algorithm isdesigned in this paper. The spatial analysis function of TransCAD software is used to analyzeurban public transit network accessibility. GISDK is used as a secondary developmentplatform and it is applied to reinforce TransCAD software.This paper takes Lanzhou public traffic system as the example to analyze its spatialcharacteristics and evaluate its accessibility level. Finally, a series of Lanzhou public trafficdevelopment strategies are put forward. The research result shows that the model is fit for theaccessibility evaluation of urban public transport system.