few moments of lateral thinking...

knight rider!

This was one of my favourite tv show when i was a kid. it seems they are going to come up with new series. though it looks like a fiction tv show, some how i think cars that run without human driving is possible.

what you need is a system which can take you from point "A" to point "B" at a regulated speed without hitting or being hit by any other vehicle.

A perfect co-ordination between, steering, acceleration and brake could do that. You already have GPS for navigation, Lexus has automatic steering control for parallel parking. this can be extended for steering and driving when the vehicle is in motion.

Volvo and other vehicles have sensors that detect if there are any vehicles close to yours and signals. a sensor which can relate this signal to the accelerator and brake could help control when the vehicle is motion to prevent the vehicles from accidents.

A GPS with preprogrammed speed, could control the accelerator depending upon where you are. the only things that are left are stop signs and of course human intervention. if some electronic sensors are placed on stop signs which can be detected by the vehicle then that problem is avoided. for human intervention, you could always have human override, but may be humans should stop interfering!

With a handful of sensors and a desire to make it, this car can no more be a fiction.

May be it might come to existence in market in the 22nd century.