Not long ago, self-driving cars seemed like science fiction. In a report backing self-driving cars, the consulting firm KPMG and the Center for Automotive Research recently predicted that driving is “on the brink of a new technological revolution.” Though, there are some compelling reasons to support self-driving cars like they can make driving more efficient and safer by eliminating distracted driving and other human errors. But as the momentum for self-driving cars grows, one question is gaining momentum: Should they even be legal? And if they are, how will the laws of driving have to adapt? All our rules about driving — from who pays for a speeding ticket to who is liable for a crash — are based on having a human behind the wheel. This will have to change. As self-driving cars become more common, there will be a flood of new legal questions. If a self-driving car gets into an accident, the human who is “co-piloting” may not be fully at fault — he may even be an injured party. Whom should someone hit by a self-driving car be able to sue? The human in the self-driving car or the car’s manufacturer? New laws will have to be written to sort all this out.