After decades of increases, the growth in driving in the United States is levelling off, and dropping on a per capita basis. These shifts have enormous implications for public policy in the US and abroad, as evidence shows that this phenomenon is generally reflected in developed counties around the world with mature transportation systems. Yet while there is little doubt that the sputtering US economy has a major impact, emerging research suggests the changes in driving habits also result from a long-term structural change, reflective of a host of shifts in demographics, culture, technology, as well as settlement patterns in US metropolitan areas. But whether due to a momentary blip or long-term structural changes, the changes have important implications for public policy. For example, US roadways are arguably safer and less congested. However, the resulting declines in gasoline consumption also result in less revenue collected from gasoline taxes and fewer resources for all modes, including public transport. The key is for policymakers to understand these new developments and their impacts on transportation finance, the environment, and general economic development. This paper explores those macro forces through an analysis of driving trends, a review of existing literature and a discussion of what is likely behind these trends, as well as implications for public policy.