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Title:

Effective GPS-Based Panel Survey Sample Size Analysis for Before-and-After Studies Using Generalized Estimating Equation Method

Accession Number:

01337210

Record Type:

Component

Abstract:

This research develops a framework to estimate the effective sample size of Global Positioning System (GPS) based panel surveys in urban travel behavior studies for before-and-after analysis. Recent advances in GPS monitoring technologies have made it possible to implement panel surveys with lengths of weeks, months or even years. The many advantageous features of GPS-based panel surveys make such surveys attractive for travel behavior studies, but data collected from such surveys feature within-household correlations that arise from the panel design, and often non-normal distributions, both of which should be taken into account at the design and analysis stages. The sample size analysis in this paper focuses on examining impacts of a policy measure on travel behavior through before-and-after studies. The sample size analysis is based on the GPS data collected in the multi-year Commute Atlanta study. The basis for the framework and methods of sample size estimation are derived from sample size procedures featuring the generalized estimating equation (GEE) approach. These sample size procedures have been proposed for longitudinal studies in biomedical research. This paper adapts these procedures to the design of panel surveys for urban travel behavior studies with the information made available from the Commute Atlanta study. The findings from this research indicate that the required sample sizes should be much larger than the sample sizes in existing GPS-based panel surveys. This research recommends a range of sample sizes based on the objectives, assumptions and survey lengths of before-and-after studies.

Monograph Accession #:

01329018

Report/Paper Numbers:

11-3501

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Xu, Yanzhi
Guensler, Randall

Pagination:

19p

Publication Date:

2011

Conference:

Transportation Research Board 90th Annual Meeting

Location: Washington DC, United States
Date: 2011-1-23 to 2011-1-27
Sponsors: Transportation Research Board

Media Type:

DVD

Features:

Figures (5) ; References (21) ; Tables (3)

Uncontrolled Terms:

Sample size

Subject Areas:

Data and Information Technology; Highways; Planning and Forecasting; I20: Design and Planning of Transport Infrastructure

Source Data:

Transportation Research Board Annual Meeting 2011 Paper #11-3501

Files:

TRIS, TRB

Created Date:

Feb 17 2011 6:32PM