Estimation of Transit Origin-Destination Matrices from Passenger Counts Using a Frequency-Based Approach

This paper investigates the transit passenger origin-destination (O-D) estimation problem in congested transit networks where updated passenger counts and outdated O-D matrices are available. The bi-level programming approach is used for the transit passenger O-D estimation problem. The upper level minimizes the sum of error measurements in passenger counts and O-D matrices, and the lower level is a new frequency-based stochastic user equilibrium (SUE) assignment model that can determine simultaneously the passenger overload delays and passenger route choices in congested transit network together with the resultant transit line frequencies. The lower-level problem can be formulated as either a logit-type or probit-type SUE transit assignment problem. A heuristic solution algorithm is developed for solving the proposed bi-level programming model which is applicable to congested transit networks. Finally, a case study on a simplified transit network connecting Kowloon urban area and the Hong Kong International Airport is provided to illustrate the applications of the proposed bi-level programming model and solution algorithm.