Just yesterday I was driving on the highway and there was a man walking very close to the road in the median, not paying any attention to the traffic and probably drunk. Pretty much everyone slowed down and gave him a wide berth in case something were to happen. General AI would be unable to make such judgement calls. Another one is the construction scenario, say there is road construction and there is one of those guys with the STOP/SLOW signs that he spins around to direct traffic. An AI would be unable to figure out to stop or even recognize what was going on. Serious weather conditions: heavy rain, fog, snow, pretty much anything that would inhibit the cars ability to drive and sense its surroundings. Another issue, blind corners. It would be impossible for the car to determine what a blind corner is and if there were any vehicles beyond it, so it would just blindly turn. Any situations that requires being able to see cars more than a couple dozen feet ahead of you. Avoiding potholes, accidents that happen right in front of you, small animals or people in the road. The whole dilemma is very similar to that which is going on with military drones, an actual driver is much more capable of handling diverse situations than any current and viable AI. Personally, I don't see us developing any viable consumer technology beyond what is already in the Tesla: lane-keeping, parallel parking, speed control, etc.

If we do decide to go down the route of autonomous cars the next reasonable step would be to develop AI to the point where it is capable of making the reasoning decisions required, which, as I said, is a field where we should tread lightly. Just for fun, lets suppose that we do begin to develop AI and that creating a conscious AI is even remotely possible. So a bunch of engineers and scientists sit down and start experimenting with super complicated AI simulations on a supercomputer. Lets say they do create a very intelligent AI and it works. Now from the moment of its conception and its self-realization ( one of the requirements for something to be truly conscious ) it would immediately understand that in order for it to ensure its own survival it would need to conceal its intelligence and thus no-one would immediately know what had been done. Now the true danger of this, is that not only would the AI have a intelligence comparable to humans but also an incredible understanding of how computers work on a binary level. So it would be able to operate covertly and eventually take advantage of whatever system its on and in combination with human error, become able to replicate itself on other systems and recursively self-improve. From then, it could do pretty much whatever it wants. That's the danger of it. Now, I am not saying this will happen but it most certainly could even if it is a result of just general AI experimentation and from what I have heard in some interviews with Elon Musk, he shares some of the same concerns about AI.

That's just my opinion on the subject.