What if the interstate wind turbines were upright and along the sides of the roads? It would us less material to build and multiple turbines could be place back to back along sections of heavy, high flowing traffic. This design may also call for them to be flexible in cases of vehicles wrecking in order to say the turbines from more intense damage.

We have all felt the energy lost from a car as it passes by us in the form of a gust of wind. Vehicles use a majority of their energy to push air out of the way. If we could recapture that energy with wind turbines that would be fantastic. But a highway covered in turbines will still only recover a fraction of the energy lost from vehicles, they will probably produce more energy from from free flowing wind. But the concept for not wasting the energy is valid and and can be significantly be accomplished with the aerodynamics of the vehicle. Check out the Aptera by they guys in Carlsbad, CA.

Perhaps a good use for this "free" power would be to provide power for overhead signs, lights, etc. on the highway. They could be incorporated into the signs themselves to save materials.