Estimating Transit Passenger Origin Destination Flows Using Boarding and Alighting Counts

Abstract:

A large amount of passenger boarding and alighting counts at stops can be collected by Automatic Passenger Counter (APC) systems. APC data describe passenger Origin Destination (OD) flows at the aggregate level and, therefore, can be used to estimate passenger OD flows. In view of this, an OD flow estimation formulation based on the distribution of the APC data is proposed and a computationally efficient Heuristic Expectation Maximization (HEM) algorithm to solve the proposed formulation is developed. The effects of the quantity of the APC data, APC measurement errors and OD survey sample size are considered in the methodology evaluation and comparison. It is revealed that the HEM algorithm takes better advantage of the APC data than traditional methods and that it outperforms a simulation based approach that was recently proposed in the literature in terms of both estimation accuracy and computational efficiency.

Key words:Transit, OD (Origin Destination) Estimation, EM (Expectation Maximization) algorithm, APC (Automatic Passenger Counter) System