That's up to the politicians, and they can be more unpredictable than road conditions. All of the driverless concept-cars that I've heard about (except Google's) are optionally autonomous. They still have conventional controls and can be driven by humans if necessary or desired. Presumably an individual without a driver's license would be allowed to be a passenger in such a car, but couldn't take the controls. But current law governing testing of autonomous vehicles (they are all considered experimental) on public roads requires that they have conventional controls and 'safety drivers' behind the wheel, ready to take over if the computer chokes. When autonomous cars finally go on the market that might still be the legal regime in some places, so they will still have to have a licensed driver aboard. Interestingly, plans for production versions of Google's little pod-car don't include any steering wheel or pedals, so they can't be manually driven at all. (The test versions still have conventional controls.) Everyone aboard these cars would be a passenger, so there probably won't be any driver's license required for these vehicles.