[kgrin]

Many lights and transportation networks already do (NYC is one great example). It's not just lights - there are all sorts of inputs into that system.

It does take some resources, so you typically don't see that sort of intelligent routing outside of the major cities (at least in the US), but the tech is definitely there (not that it couldn't be improved).

[ericfranklin]

Yes, I suspect major cities already have complex and optimized traffic routing, along with full-time traffic engineers. The mid and small cities are what I experience most, but I suppose these also have less traffic, so less need to be fully optimized.