There has been much attention paid recently to the issue of petroleum dependency in the transportation sector and the environmental, economic, and political issues associated with such a dependency. This has resulted in a scramble to develop and promote alternative energy carriers and vehicle technologies to power our transportation sector including hydrogen, biofuels, and electricity produced from non-petroleum sources powering both conventional and advanced vehicles such as plug-in hybrids and fuel cells. While much has been said about the relative advantages of these various energy carriers and vehicles, very little is known about the interconnected decision processes, technical advancements, and activities that need to occur before a viable commercial product can be introduced and eventually diffused into the marketplace, such that it can make a marked difference in our demand for petroleum.

This paper defines the necessary actions, actors, and processes that are required to initiate a transition to non-petroleum fuels in the transportation sector with an initial focus on hydrogen and fuel cells. By understanding the detailed steps that must be taken to initiate a viable commercial market, we will begin to understand the timeframes when these alternatives could begin to account for significant percentage of our transportation energy needs. This paper uses scenario analysis techniques and historical analysis of hybrid vehicles and other alternative energy technologies to evaluate plausible transitions to hydrogen and fuel cells in the light duty vehicle market. The methodology is also applied to the current transitional scenarios under development by the US Department of Energy's Transition team. We find that the current scenarios for new vehicle and fuel adoption, while plausible, may be overly optimistic.