We've said it before and we'll say it again: a world with driverless cars isn't that far off. Europeans have been exploring driverless platoons called "road trains" as the future of car commuting. Computer scientists are thinking about how to reconfigure intersections and traffic lights to make driverless city driving more efficient. American cities may soon compete to build driverless infrastructure.
So the biggest roadblock facing a driverless world isn't necessarily technology, but legality. The question of who would be liable in the event of an accident — the human "driver," the car's owner, the manufacturer — remains an open and deferred one. The Wall Street Journal recently reported that only three state legislatures have weighed in on the matter. Only one, Nevada, has given driverless cars the legal green light, and even then only for testing purposes.
Over at the blog Marginal Revolution, economist Tyler Cowen points to a recent research paper by Bryant Walker Smith, a fellow at Stanford Law School, who has made the legality of driverless cars his bailiwick. In offering "the most comprehensive discussion to date of whether so-called automated, autonomous, self-driving, or driverless vehicles can be lawfully sold and used on public roads in the United States," Smith argues that driverless cars are "probably legal." He concludes [PDF]:
Current law probably does not prohibit automated vehicles — but may nonetheless discourage their introduction or complicate their operation.
Unlike many journalists and policy-makers, Smith begins his analysis with a presumption of legality instead of illegality. "Until legislators, regulators, or judges definitively clarify the legal status of automated vehicles, any answer is necessarily a guess," he writes. Smith's own guess turns on three "key legal regimes": the 1949 Geneva Convention on Road Traffic, National Highway Traffic Safety Administration regulations, and vehicle codes in the 50 U.S. states.
Smith doesn't think that any of these regimes expressly prohibits driverless cars. The Geneva Convention says a driver must be able to control a vehicle at all times, but that stipulation is probably satisfied if a human can override the automatic operation. N.H.T.S.A. rules don't explicitly rule out driverless cars either — though an odd rule saying hazard lights must be "driver controlled" might be a sticking point.
States codes, meanwhile, "probably do not prohibit" driverless cars in Smith's mind, but they do complicate the situation. Right now these codes all naturally presume the presence of a human driver; in New York, for instance, there's a rule that drivers must keep one hand on the wheel at all times (who knew?) that could become a problem in an automated-vehicle world. Additionally, laws dictating a certain following distance might interfere with algorithms that keep driverless cars close together on the road.
The paper is certain to get people talking and thinking about the matter in a new light. "Clearly understanding the current legal status of these vehicles is therefore an important step toward ultimately realizing their potential," Smith says in closing. Boosting that understanding, more than resolving the question either way, is really his point. Driverless cars may still be far enough away for lawmakers to reach deliberate decisions about their place on the road, but they aren't so far away that it's foolish to get that deliberation going.