Research On Passenger Flow Assignment Of Urban Rail Transit Based On Travel Time Distribution

A reliable urban rail transit (URT) system is the management objective for operation department as well as the basic requirements for passengers’ travel demand. Travel time is one of the most important indicators to measure the service level of URT system, which is influenced by various factors and has obvious fluctuation feature. This fluctuation feature can lower the time reliability of URT, impact the passengers’ route choice behavior, and have influence on passenger flow assignment. On one hand, as the passenger is more and more sensitive to travel time fluctuation, it is significant to accurately master the travel time distribution feature of URT and evaluate the travel time reliability of routes, in order to meet passengers’ demand and enhance the competitiveness in urban transportation system. On the other hand, with the rapid development of URT, bringing great changes in spatial and temporal distribution features of passenger flow, accurate passenger flow assignment and section passenger volume estimation is essential in order to help operation department to make reasonable and precise operation management plan. Therefore, it is necessary to build a scientific method system to estimate the routes’ travel time distribution, passenger flow assignment and section passenger volume of URT.In this paper, the components and fluctuation of URT passenger travel time is first analyzed using the data gathered from automatic fare collection (AFC). All the origins and destinations (OD) in the network are categorized into 9 classes by all-day hourly passenger flow based on fuzzy C-means clustering algorithm. Second, on the basis of clustering results, it is verified by K-S testing that the lognormal distribution model is better applied to different classes of routes’ travel time distribution. Third, the route travel time reliability is defined from the point of probability and its indicators selected including factors related to travel efficiency and stability are applied to evaluate the route travel time reliability. Forth, based on the study of route travel time distribution in OD pairs, the travel time distribution model for OD pairs with multi-routes is established to study the travel time distribution features of different classes of travel periods using AFC data. Fifth, the method of passenger flow assignment and section passenger volume estimation are proposed based on the route travel time distribution. Finally, the case of "Xierqi-Huilongguandongdajie" in Beijing metro is applied to verify the validation of the travel time distribution model for OD pairs with multi-routes, in which the peak and off-peak passenger flow assignment ratio and section passenger volume are calculated using Monte-Carlo simulation arithmetic.