Traffic Signals Go Red when Speeding
I have heard about this concept before and it would be easy to do with appropriate detection. I'd have a hard time getting this implemented through the City staff and I would see a benefit if you could give a benefit to vehicles travelling at the speed limit.
Bluetooth for Arterial Travel Times
In other news, the following implementation in Houston has lead the way to provide performance results on arterials. We have a few units out in the field now, but have been outdone by our friends down south.