Always felt like autonomous driving without smart roads isn't going to happen on a large scale, just computer vision isn't enough. What would a smart road be?

Always felt like autonomous driving without smart roads isn't going to happen on a large scale, just computer vision isn't enough. What would a smart road be? Either some infrastructure that is designed for this or a digital overlay attached to it that every car nearby continuously updates in real time. Or maybe both. That would mean an open standard and shared access to such an overlay, plus technology for that would have to be mandatory for new cars regardless of whether they plan to be autonomous or not. Right now it's just a capitalist rat race that no one is winning.