Autonomous vehicles—self-driving cars—hold the promise to one day change the very nature of travel in the United States. For the moment, they remain mostly in the realm of science fiction, although significant developments are expected over the next decade. In 2013, Michigan became the latest state - joining California, Florida, Nevada and the District of Columbia - to enact legislation to allow automakers and others to continue to conduct autonomous vehicle research. But even as the industry and states contemplate a future for such vehicles beyond the research and development stage, some question whether these types of legislation may be premature while we still know so little about exactly what that future will look like.