There are a couple of enhancements that I think would make the road a lot safer and easier to navigate even if we can't have automated transportation vehicles yet. Brake lights on the front of vehicles would be really helpful to know if someone is actually attempting to stop. While we're modifying the brakes let's also make them even more helpful to other drivers. Include an indicator of the amount of break pressure being applied. In addition to the regular brake light there could also be a series of lights next to it that would incrementally light up the harder the brake was being pressed.
The reason I bring up these two improvements is it's hard for me to determine how fast a car is braking prior to making a turn. It would be helpful in determining if they actually intend to make the turn even if they haven't put on their turn signal, or if their turn signal is on and they're not really stopping.