I imagine that one could devise a pretty clever self-driving car that, under normal circumstances, is better than many drivers I see on the road. What I can’t imagine is that mixing these cars with the erratic drivers that are currently on the road would be good at all.
The problem isn’t that the driver can’t override the system — they can — the issue I have is that most people interested in this wouldn’t be paying attention at all.
The biggest challenge for these cars is whether they can “foresee” impending crashes. Meaning when I drive down a residential street on a nice day I keep an eye out for kids playing that may suddenly go running after a loose ball, how could a car do that? No matter how advanced sometimes you just can’t beat the human eye. Because the first time a ‘driverless’ car kills a kid in an accident that a human could have avoided — well that’s the end of the dream.