Humans are an autonomous car's biggest problem. The new Audi A8 has a solution

In 2012 the engineers working on Google's self-driving car realised they had a problem. Early testers had agreed to always watch the road in case of emergencies, but many didn't -- and it put them at serious risk. This is what's known as the handoff problem: how to alert and engage the distracted human when the computer falters. Bypass the issue by building a vehicle that operates entirely on its own. Over the next few years, several other makers of self-driving cars, companies like Ford, General Motors, and Volvo, de-emphasised or abandoned their efforts to crack the handoff problem, mirroring Google in their quest to go full robo.