01479946

Component

An iterative method is proposed to estimate bus route-level origin-destination (OD) passenger flow matrices from boarding and alighting data for time-of-day periods in the absence of good a priori estimates of the flows. The algorithm is based on the widely used Iterative Proportional Fitting (IPF) method and takes advantage of the large quantities of boarding and alighting data that are routinely collected by transit agencies using Automatic Passenger Counter (APC) technologies. An arbitrarily chosen OD matrix is used as the base matrix required to initialize the algorithm, and the IPF method is applied with trip-level boarding and alighting data and the base matrix to produce an estimate of the OD flow matrix for each trip. The trip level OD flow matrices are then aggregated to produce an estimate of the period-level OD flow matrix, which in turn is used as the base matrix for the following iteration until convergence. Empirical results are conducted on operational bus routes using APC data collected during multiple quarters where directly observed OD passenger flows are available to represent the ground-truth. In all cases where APC data are available for even a reasonably small number of bus trips, the developed method produces better estimates than the traditional application of the IPF method when using the uninformative null matrix as the base without updating. Moreover, the algorithm converges in minimal computational time, and the estimates are seen to be insensitive to the OD flow matrix used to initialize the algorithm.

This paper was sponsored by TRB committee AP050 Bus Transit Systems.

01470560

13-3375

English

19p

2013

Transportation Research Board 92nd Annual Meeting

Digital/other

Figures; Maps; Photos; Tables

Algorithms; Alighting; Automatic data collection systems; Boarding and alighting; Bus routes; Bus transit; Bus transit operations; Estimating; Origin and destination; Passenger counting; Passengers; Pedestrian flow; Trip matrices

Operations and Traffic Management; Public Transportation; I72: Traffic and Transport Planning; I73: Traffic Control

Transportation Research Board Annual Meeting 2013 Paper #13-3375

TRIS, TRB, ATRI

Feb 5 2013 12:41PM