Its possible to prove that driverless cars can be safe. And that's by keeping cars from having accidents. If safety systems can keep human drivers from having accidents by stopping vehicles before they can have an accident, they can do the same for robotic vehicles.

Such systems would place limits on how fast you could accelerate, turn the wheel or apply the brakes. And they would also brake for you when other vehicles, pedestrians and animals appear to be on a collision course.

Such systems will have to be proven in the real world. And we are starting to see them. The newest Mercedes have such features. I predict that full blown systems will dramatically lower accidents for older people, teenagers and those who drive under the influence. Eventually all new cars will have these systems.

And by then it will be a lot easier to trust the machines.