| With the rapid development of economy, the continuous expansion of urban size, urban traffic motorization degree increasing, especially in the growing number of private cars, traffic congestion is becoming more and more serious, and the city traffic pressure gradually increase. Urban rail transit because of its high-speed, large-capacity, punctuality, etc., has become an effective means of many cities to solve traffic congestion problems. Urban rail transit as a skeleton of transportation, its station and line density is relatively low. Through the effective convergence with other modes of transportation,urban rail transit in order to advantage. Various methods convergence passenger flow within the scope is an important safeguard to ensure the sources passenger flow. So it is necessary to research the scope of urban rail transit sites.Firstly, through analyze the concept of urban rail transit scope define the research problem. And then analyze the connection process of urban rail transit and other transport models, to lay the foundation for the later study that is the scope of each kind of transport models.Secondly, from the traveler’s choices of traffic modes, analysis of various travel costs involved in travel process, and the establishment of a generalized travel cost model. Based on generalized travel cost as constraints to establish a model which is about of the scope of rail transit sites,and gives a detailed algorithm. In modeling process, introducing the concept of urban rail transit accessible region and determine the weight of each accessible region to make up for previous inadequate studies to selecting only one single destination.According to the status of the road network around the station, divide the traffic zone into many smaller zone. Basis on conditions of road network and the centroid of smaller zone, calculated the transfer distance. making it closer to the actual trip distance.Finally, according to metro line two in Xi’an city as the research object, that was analyzed the scope of walking. The results show that the transfer scope has a relationship with road conditions, the level service of other modes of transportation around. The model can predict passenger flow more accurately. Through optimize ride facilities and improve access conditions within the scope of the various modes of transportation access, to ensure the passenger flow of urban rail transit. |
