Tim Bradshaw

Self-driving cars seem like a magical idea. The concept of vehicles that can operate themselves, without steering wheels or pedals, leaps straight from the pages of science fiction.
 Yet like so many fantastical stories, there are “wizards” hidden behind the curtain — lots of them. Constructing the road to fully automated driving, it turns out, requires a lot of manual labour.
 Most companies working on this technology employ hundreds or even thousands of people, often in offshore outsourcing centres in India or China, whose job it is to teach the robo-cars to recognise pedestrians, cyclists and other obstacles. The workers do this by manually marking up or “labelling” thousands of hours of video footage, often frame by frame, taken from prototype vehicles driving around testbeds such as Silicon Valley, Pittsburgh and Phoenix.