Waiting at too many red lights? The taxman likes it that way

There's a rush you get when you're driving down the street and you catch one green light after the other. In some places -- and you know the highways by heart -- you can travel for miles that way, never tapping the brakes. As long as you're going the speed limit, you can sail across some towns this way.

They call that the "green wave," and it's no accident. Traffic engineers build that timing into their systems. The "green wave" is one of the things that keeps Manhattan avenue traffic flowing as well as it does. The green wave also happens to be an efficient way to manage fuel costs and limit carbon emissions. Repeatedly pressing on the brakes and repeatedly starting from a halt burns lots of gas.

That efficiency is why some governments oppose it.