Are we wasting auto-produced energy on our freeways?

Question

I asked this once before, but got only one odd answer. I suggested putting a bunch of rollers, that cars would spin as they drive over them, on freeways. Couldn't they be connected to turbines to produce energy? I know that, initially, it would be expensive, but the cars are going be be driving the freeways anyway, and we could be taking advantage of their energy. Or, is this just a dream?

Answer 1

Wouldn't that be incredibly dangerous and waste millions of gallons of fuel? They have resource for wind, solar, thermal, and several other types of clean energy, but the cheapest and most profitable type will always involve fuel

Answer 2

the rollers would spin when cars drive over them. during that time, the car would have no traction on the road, thus causing them to slow down, and requiring more engine output to maintain the same speed, which will cost millions in wasted gas. i suggest tiny, very slightly raised plates connected to vibration generators (http://www.technovelgy.com/ct/Science-Fi... the weight of the wheel pushes it down, then it comes back up when the wheel moves past (and again for the back wheel). put a few dozen in a patch on each side of each lane in a high traffic area, and you could get a useful amount of energy. put enough at a busy intersection, and you could at least partially power a stop light