Essays on Urban Transportation and Transportation Energy Policy

This dissertation outlines three topics on urban transportation energy, emphasizing the role of transportation energy policy, and aims to provide a single comprehensive framework to evaluate and compare different pricing and regulatory policy options for reducing transportation fuel consumption in the United States. In the first chapter, I examine the effect of population density on motor fuel (i.e., highway gasoline) consumption, controlling for other variables such as gas price, income, vehicle stock and so on, using state level aggregate cross-sectional time series data from 1966 to 2004. By estimating the impact of density on fuel consumption, I improve the understanding of the conventional logic that there is a negative correlation between population density and transportation energy use due to reduced average travel distance and availability of alternative modes in denser area. In the second part, I examine various transportation energy policy instruments such as a fuel tax, a mileage based VMT tax, Corporate Average Fuel Economy (CAFE) standards, a Pay-at-the-pump (PATP), and a Pay-as-you-drive (PAYD) insurance premium to measure policy impacts through computerized policy simulations. By fully integrating three interrelated economic demand decisions - size of vehicle stock, use of the vehicle stock, and energy efficiency - it can predict short-run, long-run, and dynamic effects of a policy change. The impacts are measured in terms of vehicle miles traveled, fuel consumption, greenhouse gas emissions, and cost savings. I also examine the impact of transportation energy policies on traffic safety in terms of the number of traffic accidents, traffic fatalities, and total accident costs. The outcome of this research provides a set of specific results comparing policy scenarios in a consistent manner. The results will provide guidance concerning whether the policy option would reduce energy dependency as well as undesirable side effects such as environmental problems and safety problems of motor-vehicle travel.