According to the National Highway Traffic Safety Administration only 5% of accidents are caused by mechanical failures.
Drunk driving alone (at least in 20004) is the cause of 30% of fatal accidents during the weak and over 50% during the weekend.
So even if car maintenance is still left to humans, we'd see a massive decrease in car accidents and subsequent deaths.
>will those driverless vehicles be capable of handling the unpredictable human drivers on the road?
With certainty, yes they will, and with much better reaction times than humans. In 2004 at the DARPA grand challenge the farthest any car got was 11.78 km.
1 year later 22 cars got farther than that, and 5 completed the race (240 km).
Self driving cars have only kept improving over the last few years. The Google car has never had an accident while in autonomous mode, only while a human was in control.
Self driving cars will be here. When is going to be dictated
legislation, but when that time comes, they will save tens of thousands of lives per year.
If those are addressed by driverless cars (ie, johnny-cab) then we're probably going to see a significant drop in freeway accidents.
On the other hand, will those driverless vehicles be capable of handling the unpredictable human drivers on the road?