that could measure a vehicle's emissions as it drove by. The system works very well but he's having a hard time getting the state to accept it. It seems the state would rather have everyone's vehicle tested for emissions rather than actually go after those vehicles that pollute the most. It turns out that those old cars each release about as much pollution as 400 new cars put together. Instead of trying to get those cars off the road, they're given looser emissions standards. In that vein, I had to laugh a few months ago when I saw someone driving an old VW Bug with an "Earth First" bumper sticker. That Bug doesn't get any better gas mileage than my Honda CRV (a quasi SUV, horrors!) and pollutes hundreds of times as much. If he really cared about the environment, he'd scrap the Bug and get a cleaner running car.

As for a device to measure how much a vehicle weighs as it drives by, I can't think of any way to make it work.