Traffic signals in the information age

I’ve begun to wonder if we’re starting to see a revolution in how we think about traffic, or if this has been around all along and I’m just now noticing it.  Here are a few different proposals for ways to improve traffic signaling.  I think it’s especially interesting that some of these systems are incorporating a little bit of logic into them so they are more ‘aware’ of their contexts.  The idea of using LED screens allows for multiple use information display.  This also allows for flexibility.  One of the proposals shows how the presence of emergency vehicles changes the behavior of the sign.  Imagine if it were taken just a little bit further and police could temporarily block of a section of road (for an accident, let’s say) by changing a solid green light to an arrow green light at the surrounding intersections.  Or maybe a traffic signal gets knowledge of the road surface conditions though sensors and changes the yellow light duration depending on conditions.  In bad weather maybe it would show yellow a little longer than in good.  Or maybe some more situational awareness could solve this problem: ever been on an empty road and get a red light just as you approach an empty intersection?  To top it off, you wait trough the full red light and just as you get the green light one car enters the intersection getting a red light.
Traffic signalling has an enormous impact on our fuel consumption as a nation. It sounds silly, but think about it.  The two times you get the worst gas mileage are when you are accelerating and when you are stopped.  If Gary Lauder is right (see last video in this post), we spend about $.05 in gas per car per stop sign.