How do you design a fail-safe driverless car? That's a trick question, of course, because you can't.
So engineers are doing the next best thing: developing backup systems for the brakes, steering, sensors and computer chips that guide a self-driving vehicle.
The idea is to give vehicles secondary systems that will allow them to safely pull over in case of a catastrophic equipment failure. But to keep a lid on redundant costs, suppliers are developing components that can be programmed to handle more than one function.
Ideally, such dual-use components simply will need extra software to handle their emergency tasks.