Most cars will still have the option, but as insurance companies see that those cars with autonomous ability get in fewer accidents, insurance rates will drop accordingly. Eventually, in the distant long term, it will be the autonomous ability that comes standard on all cars, and the manual ability that is an optional feature.
I don't think having a manual driving option should be illegal and I don't think it would be made illegal. You might have some legal restrictions on manual driving though in the form of automated-driving-only lanes, similar to HOV lanes today. An automated driving lane could go 120 mph and have less space between cars (in good weather, of course).
Regarding the quality of GPS units, if you watched the video I posted earlier then it is clear that there is a huge difference between a GPS unit that is essentially blindly reading a map and the automated car that can see everything around it and adjust accordingly.
It is also silly to think that kinks won't be worked out such as the software knowing which dirt roads will be able to support the vehicle and which will not. It really surprises me that anyone who has been awake during the past few decades does not understand that software improves.
I have windows 8 which is the biggest computer mistake I have made. I have been involved with computers since the mid 70’s and have been certified on multiple systems.
Hackers would have a field day with traffic. People are concerned about the power grid so lets add cars to it. An EMP or solar flare would completely stop the nation. How would people that can't set the clock on a VCR tell a car where to go?
Simply put I think we have a pretty decent analogy and it’s autopilot on airplanes. It’s not a case of either planes flying themselves or people flying them - it’s a case of having both capabilities with a strong presumption of a human being able to override the machine whenever it’s prudent to do so.
Not only do we have this airplane analogy - this is also the way that self driving cars work today - with a human tasked with taking over should the need arise.
This is not hard to think about. Over time the confidence in the systems will increase and the infrastructure and the culture will evolve to make it easier and more “normal”. I don’t however, foresee, a family of four sleeping their way across Colorado and Nebraska while the car drives itself.
You don’t (or shouldn’t) do that in a plane today and I don’t think you’ll be doing it in a car tomorrow.