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SWUTC Ph.D. Candidate Assistantship Project Description

Examining Decision-Making Surrounding the Use of Managed Lanes by Katy Freeway Travelers: A Prospect Theory Approach

University: Texas A&M University

Principal Investigator:
Chao Huang
Zachry Department of Civil Engineering
(979) 845-5674

Faculty Supervisor:
Mark Burris
Zachry Department of Civil Engineering
(979) 845-9875

Funding Source: USDOT Funds

Total Project Cost: $32,079

Project Number: 600451-00023

Date Started: 12/1/12

Estimated Completion Date: 2/28/14

Project Summary

Project Abstract:
This study will be the first attempt to examine the potential application of prospect theory (PT) in stated preference (SP) and reference point (RP) data to predict route choice between managed lanes (MLs) and toll-free alternatives. Using the PT proposed utility function and a probability weighting function, this study will estimate the value that travelers are willing to pay for travel time savings and travel time reliability on MLs. This research will compare the prediction results with results of previous studies using expected utility theory (EUT) on Katy Freeway in 2010 and 2008. Willingness to pay estimates will be obtained by fitting discrete choice models to the SP survey data. In addition another potential important contribution of this study could be the development of a unique probability weighting function for ML users – this has not been done by any previous research. Another important issue in the application of PT in route choice decision is the reference dependence – how travelers would rate gains and losses in travel time with regard to the reference point. This study will investigate the impact of different reference points on travelers’ route choice decision. Travelers with similar characteristics, such as gender, age, household income, etc, may behave differently in their use of MLs. Value functions with different parameter estimates will be obtained for each group of travelers. This study will also examine two different survey design strategies for their ability to estimate the discrete choice model parameters. By including the probability of occurrence of the possible travel time of each alternative in the survey, this study will be the first attempt to test the efficiency of two design strategies (Db-Efficient and adaptive random) used to generate the SP questions.

Project Objectives:
The primary purpose of this research is to determine if PT is superior to EUT when predicting and understanding travelers’ behavior in the case of MLs. This research will accomplish the following specific objectives:

  • To estimate the parameters of the PT proposed utility function and probability weighting function. Previous research in behavior science have suggested four potential probability weighting functions. This study will compare the prediction results from different weighting functions to determine which one results in the best prediction. Given availability of the data collected from the survey, this study will also take an attempt to develop a probability weighting function that may fit the data better.
  • To test several psychological phenomena (as identified by PT in other research areas) in travelers’ choice decision between MLs and toll-free alternative. These phenomena include: the reference dependence, loss aversion, and risk seeking.
  • To estimate the value of travel time savings (VTTS) and travel time reliability (VTTR) for ML travelers using both EUT and PT proposed utility and probability weighting functions.
  • To compare willingness to pay (WTP) estimates of the survey respondents with WTP estimates from previous SP and RP survey, as well as the WTP estimate from actual ML usage data. Also to identify the design strategies that best approximate the actual WTP.
  • To test the impact of the framing of questions in the SP survey on the estimate of VTTS, VTTR, and WTP. Two question framing strategies are: (1) implicitly assumes traveler’s most recent travel time as the reference point, (2) gains or losses in travel time are explicitly indicated in the question.

Task Descriptions:

Task 1. Literature Review

Task 2. 2012 Katy Freeway Survey Design

Task 3. Data Collection

Task 4. Data Analysis