State Departments of Transportation (DOTs) today are seeking financing alternatives so that transportation infrastructure investments can become less dependent on the amount of fuel U.S. drivers consume. Because the fuel tax is no longer viewed as a sustainable and stable option, other financing alternatives are being considered. One such alternative includes the vehicle miles traveled (VMT) fee. Examples of such VMT fee alternatives include: 1) collection using an onboard diagnostic system (OBD), 2) collection at the fuel pump using an OBD in conjunction with GPS technology, and 3) collection at a vehicle inspection station using the OBD. This proposed research has two primary objectives: 1) to conduct a comparative review of VMT fee alternatives and their data collection methods, payment collection processes, expected costs and revenues, and anticipated challenges; and 2) to examine the suitability of these VMT fee alternative for consideration in Massachusetts. The major results and conclusions are the fuel tax, if increased and reviewed annually, is a viable short term solution and that a VMT fee should be considered further as part of a long term strategy. It is expected that the results of this research will be of interest to Federal and State DOT personnel and policy makers.

Transportation funding is critical to maintaining the assets that provide mobility for the movement of Georgia's people and goods. Currently, most of Georgia's transportation revenue is provided by the motor fuel tax. Inflation and recent increases in fuel economy have decreased fuel tax revenue in Georgia and weakened the Georgia Department of Transportation's (GDOT)'s ability to maintain and expand its transportation network. This thesis synthesizes factors from literature that affect motor fuel tax revenue. These include demographic, economic, technological, and environmental forces that influence travel behavior and vehicle fuel economy. A model was then created that incorporated these factors to model GDOT's 2009 fuel tax revenue and then project revenue in 2020 and 2030. The model uses an input/output structure that segments the fleet into personal, freight, and transit categories. User inputs, historical data, and projections are linked via relationships and feedback loops to project travel and fuel tax revenue forward. Because a near-infinite number of scenarios exist, conservative and aggressive scenarios were created for 2020 and 2030 scenarios that output revenue on an absolute, per-mile, and per-capita basis for comparison with more recent revenues. The model outputs predict marginal declines in revenue by 2020 and significant declines by 2030. In response to these declines, the thesis evaluates methods of increasing transportation revenue. These methods include increasing the fuel tax, incorporating a VMT-fee, and widespread tolling measures. After evaluation, a policy recommendation is provided for how to best implement revenue strategies.