University of California Transportation Center
The Impact of Transportation Infrastructure on the Value of Time
- Author(s): Barrett, James
- et al.
In this dissertation economic values time of are estimated as a function of public transportation infrastructure. These results provide insight into the value of improvements in transportation infrastructure that can be useful to policymakers who need to consider the value of time saved when looking at the optimal allocation of transportation projects. This research contributes to our understanding of the value of time and in particular how the value of time is impacted by current levels of transportation infrastructure.
To analyze the value of time as a function of transportation infrastructure a combination of Geographical Information Systems (GIS), US census and survey data is employed. Empirical random utility maximization models in a mixed logit (MXL) framework are developed consistent with time and money‐constrained choices. Both revealed preference (actual choice) and stated preference (hypothetical choice) models are analyzed.
The use of an internet based survey for this dissertation was especially important. In particular, the use of the internet based survey guaranteed that answers for questions related to time spent on various activities during the respondent’s day added up to 24 hours. This ensured that the models of time developed in this study had a degree of accuracy that is much more difficult to achieve with other survey methods. In addition, the internet based survey made it possible to provide detailed instructions and examples that a respondent could view if she needed a fuller explanation of a particular question. Consequently, the survey employed in this study presented a complex set of questions that were easy for the respondent to answer.
Three communities are studied including the cities of San Francisco and Sacramento and Sonoma County in Northern California. Specifically, the value of time is modeled as a function of the currently available public transportation infrastructure. As such, the value of time is shown to vary between communities and within communities as a function of the level of transportation infrastructure in the immediate neighborhood of each individual’s home. Using Contingent Valuation Methods (CVM), an economic welfare analysis shows that increases in levels of transit infrastructure have positive economic impacts that vary in relation to the current level of infrastructure.