On a busy downtown street, three delivery bikes suddenly dart over the pedestrian crossing ahead of a car. On the car's dashboard they look like small, blue 3D blocks from a 1990s video game.

The steering wheel turns itself a notch and the vehicle slows to a gentle halt, while the safety driver looks on from the passenger seat.

The vehicle is one of a hundred sensor-laden "robotaxis" belonging to startup DeepRoute.ai cruising the dense central Futian business district in China's southern tech hub Shenzhen, giving 50,000 trial rides to passengers in the last year.