Four self-driving buses were tested on public roads in Shenzhen, Guangdong province on Dec. 2, 2017. It was believed to be the first such live test in the world.

Each bus looks like a normal one. There's even a driver in position for safety. But the new buses are steered automatically along designated routes without a driver's hands ever touching the wheel.

They can automatically avoid pedestrians, speed up, slow down, make an emergency stop, change roads and navigate traffic lights.