SWUTC Research Project Description

Title of Project: Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation

Project Number:  476660-00074

Principal Investigator:
Randy Machemehl
(512) 471-4541
P.I. Affiliation:  University of Texas at Austin

Project Monitor:
Surinder Marwah
Capital Metropolitan Transit Authority
Austin, TX
(512) 369-7047

Project Status:  Active

Date Started:  9/1/09

Estimation Completion Date:  8/31/10

Estimated Cost - Current Fiscal:  $58,000

Estimated Cost - Total Planned:  $58,000

Project Summary:
Project Abstract:
Increasing fuel prices are driving travelers to find ways of controlling their travel costs and this travel cost motivation has led to historic high levels of transit ridership. Transit providers are searching for ways to provide sufficient system capacity; however, they are experiencing increasing costs due to fuel prices and stable or decreasing available funds.  This situation means that public transportation providers must adapt their service concepts to maximize the goodness of fit between traveler demands and service types.  Transit planners have for years considered traveler trip length as a fundamental indicator of the best mix of transit modes.  User perceptions of travel cost for transit versus auto modes are clearly related to traveler trip length but relationships among traveler trip length, perceptions of comparative travel costs and transit modes have not been clearly identified.  The proposed research will examine traveler trip lengths across transit modes and develop predictive models of how traveler perceptions relate to the trip length mode choice issue.

Project Objectives:
The proposed research will examine traveler trip lengths across transit modes and develop predictive models of how traveler perceptions relate to the trip length mode choice issue.

Task Descriptions:
Task 1.  Synthesize Available Literature
The research team is already familiar with much of the existing literature that is relevant to this project, however, an exhaustive search will be conducted to guarantee completeness.  All information will be synthesized to form a complete summary.

Task 2.  Analyze Traveler Trip Length versus Mode Data
As noted earlier, a vast amount of descriptive data regarding traveler trip lengths for transit modes currently operating in the United States has been procured by the research team.  A detailed examination of these data will be conducted.  Since the data are available for each of the many transit systems reporting to the Federal Transit Administration (FTA) , the system level information has implicitly included metro area travel behavior and socio-economic characteristics.  Part of the analysis process will include identification of metro area size and behavioral and socio-economic variables that can explain differences among the trip length characteristics across the included cities.  The objective will be development of robust models that can predict trip length characteristics as a function of metro area characteristic predictors.

Task 3.   Develop Traveler Access Time Model(s)
A significant part of the overall trip time experienced by travelers using public transportation is time spent traveling to the transit station, waiting for the line haul vehicle, and traveling from the destination station to the ultimate destination.  The sum of these times is often called the “access time” and the significance of the access time in mode choice decisions is dependent on the fraction of total trip time represented by access time.  That is, if the line haul trip is long enough, travelers may be willing to spend significant access time, however if the line haul trip is not perceived as significant enough, access times become distinctly undesirable.  A conceptual access time model(s) will be developed as a complement to the trip length model(s) of Task 2.

Task 4.   Develop Traveler Perceived Auto Cost Model
A model that predicts perceived cost of auto travel will be developed using trip length information developed through Task 2.  The model will provide optional user specification of fuel cost or use of national average data as well as, user specification of auto fuel economy or fleet averages.

Task 5.  Develop Traveler Perceived Transit Cost Model
A model predicting the traveler perceived cost of travel by transit will be developed.  The model will include fare costs and based upon the access time model of Task 3, an equivalent cost of the time associated with transit system access.

Task 6.  Combined Cost Model and Observed Transit Ridership
The models of Tasks 2 through 5 will be combined to yield a predictive model for user perception of cost differential between auto and transit, which will be related to mode specific transit ridership data for approximately 500 U. S transit systems.  Mode specific unlinked transit trip data have been procured for the last 10 years and are currently being examined by the research team as part of a related research project.

Task 7. Transit Mode Applications and Trip Lengths
Based upon the Task 6 model and the trip length data for U. S. transit systems, guidelines for transit mode application will be designed.  Guidelines will include observational data describing trip lengths as well as model estimates of user cost perceptions.  Although all generic public transportation modes will be included, special emphasis will be given to the BRT family of services.

Task 8.  Documentation
A comprehensive report documenting all research including data sources will be developed.  Models and implementation aids will be fully explained and illustrated.

Index Terms: