I was wondering how the prototype handles signs, as it doesn't have any infrastructure built to support it.Stop signs and speed limits are easy enough, RFID transmitters or pre-programmed maps with the pertinent areas mapped out ahead of time will easily suffice.
That might work in some areas, but there are 2 major problems. The first in that city driving in urban areas is beyond the ability on sensors to handle. Safe driving techniques require societal knowledge of how other cars will operate and reading the body language of pedestrians. The second is that maintaining millions of senors is both expensive and inevitable failures will be a problem. Staying limited to highways is much more practical if you want a controlled environment.Visual sensors could detect the prescience of something in the roadway that was not supposed to be there and make the car react accordingly or we could go the opposite route, embedding sensor networks into our roads to make them able to detect such things and transmit that data to vehicles on the road.