Over at Inhabitat, there are two posts on using wind created by traffic on highways to generate electricity. A student proposes horizontally placed wind generators over highways, much like road signs are placed now (pictured).

A proposal coming from New Jersey has the generators built into the highway that powers a light rail system. Awesome!

The design, a runner-up in the 2006 Metropolis Mag Next Generation Design Competition proposed the integration of wind-turbines into the highway barriers that divide the traffic. These turbines would generate power from the wind created by the vehicles that drive past them in opposite directions. Originally conceived as a single row of vertical-axis rotary turbines, it has now been redesigned to include two rows, one stacked on top of each other, with the end power being used to power a light rail system.