[Nitramp]

The kinetic energy of a car at 9 m/s (20 mph) is about 15 Wh, depending on its weight. The kinetic energy of a bullet is about 0.2 Wh.

This obviously doesn't quite translate, but the amount of damage you can do with a car is massive, even at that speed. Also consider the weight, eg when rolling over a pedestrian.

[stadium]

The reaction time of a human should prevail before they look both ways to cross the street.

[Nitramp]

What if the car gets the right of way wrong? What if there's a distracted kid, or the car misses a pedestrian crossing?

I don't think you can set something loose in traffic that relies on everyone else correcting for its mistakes.

[stadium]

I think I agree with you.

My point is, if I see a car coming, I'm not going to cross the street and let it hit me. That's the reason parents teach their kids to look both ways before crossing the street. Some idiot driver, human or otherwise, may not be controlling their vehicle in a predictable manner. At 20mph, as a pedestrian I can make a good decision about crossing the street.

I feel much safer about an empty driverless car at 20mph on local roads than one full of passengers at highway speeds.

(20 mph is entirely made up, it could be higher or lower in relationship to actual human reaction times)

[xbmcuser]

human drivers do that all the time from getting distracted with your handphone, falling asleep in the driving seat, driving while drunk or otherwise impaired. So it is not much different. But AI cars are likely to be better drivers 2-3 years from now than what they are today humans will either be the same or worse.