It is this loss of control which creates skepticism, not magical thinking about the nature of technology. Most people are surrounded by examples of technology not working, they know it's fallible, they would be afraid of autonomous cars for the right reasons - because the intent of autonomous cars is to deny them the ability not to trust technology blindly.
There is no doubt about that we'll have robotic cars. But when, thats a million dollar question.
The changes will be gradual and they have already happened to a degree. Automatic brakes have already been implemented, more expansive GPS is happening. Next I could see an expansion on cruise control.
Its a combo between marketing new features and iterating on current technology.
I think the invention of the automated car will be a gradient, not a sudden occurrence.
When the time comes to debate it, everyone is going to make the argument that they are still safer than human drivers. That wasn't true for the train operators.
Are you offering 1000:1 odds, for example, on your "never" claim?
Let's look at the recent MetroNorth railroad accident. Immediately afterwards, people were inevitably throwing around the idea of "why do we need train drivers at all?". The reason we need drivers is to satisfy a fundamental human misconception:
A while back, the DC Metro installed an automated train control system, with the intent of making the system independent of human operators. They flipped the trains onto automatic, and for a while everything ran fine. Then, one day, a sensor failed and one train plowed straight into the back of another at full speed while it was sitting in the station. That was the end of automatic train control in DC.[1]
Keep in mind that railroad traffic is a much more controlled environment than the open road.
Everyone knows that people make mistakes. We're (mostly) all engineers here, and we understand that technology is also flawed, like its creators. However, the public at large has this opinion that technology is magic; computers _don't_ make mistakes. The second that belief is proven wrong, people are immediately afraid of it.
Maybe one day a few robot cars will make it onto the road. But then someone is going to get killed by one. And despite these robotic cars having a stellar record up until their first accident, especially when compared to their human-operated counterparts, they will be taken off the road so fast your head will spin.
[1] http://en.wikipedia.org/wiki/June_2009_Washington_Metro_trai...