[rcxdude]

Reading signs is the really, really easy part. If your vision system can't read and recognise the signs and signals reliably, it's not even beginning to solve the other problems. Trying to adapt the roads to make this part easier is a terrible return on investment. 99% of what you could do to make roads easier to use for self-driving cars is basic maintenance: making sure the signs, markings, and signals remain clearly visible, which also helps improve the performance of human drivers.

[8note]

Hmm. Reading signs automatically could be added to human driven cars, I think.

Eg. Putting the current speed limit on the speedometer

[sega_sai]

That already exists. I.e. I know for sure in the UK some Toyotas have it (even pretty cheap ones).