01552823

Component

Practitioners have been aware of response bias in transit surveys for some time, particularly with respect to differences in response rates by individual routes and times of the day. More recently, transit planning practitioners have been focused on mitigating sampled flow bias; striving to ensure that the sampled or expanded sample flows reflect actual conditions. Two applied solutions have been utilizing iterative proportion fitting (IPF) techniques and collecting auxiliary flow data. These strategies have been applied in relatively straightforward situations, such as closed transit systems with known passenger entry and exit movements or single transit route/line scenarios. This paper presents the systemwide application of both techniques to a bus system with 66 routes and approximately 60,000 boardings per day. To the authors’ knowledge, this is the first time such a rigorous and intensive expansion methodology has been applied at a systemwide level in the United States. Evidence supporting the mitigation of flow bias evident in standard sample expansion techniques is presented. Issues and challenges associated with this intensive effort are presented, and process improvements for future endeavors are provided. Future research suggestions are also presented.

This paper was sponsored by TRB committee AP025 Public Transportation Planning and Development. Alternate title: An Application of Mitigating Flow Bias from Bus Origin/Destination Surveys in a Transit System.

01550057

15-0324

English

16p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; Maps; References; Tables

Bias (Statistics); Bus transit; Origin and destination; Travel surveys

Iterative proportional fitting

Planning and Forecasting; Public Transportation; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2015 Paper #15-0324

PRP, TRIS, TRB, ATRI

Dec 30 2014 12:14PM