George Carlin once proposed a system where people would shoot suction cup darts at cars when they did something annoying, like cutting you off, and if you got too many darts the cops would pull you over. Another friend recently proposed a lot of interest in building some sort of reputation system for cars using computers.
Though Carlin's was a satire, it actually has merits that it would be hard to match in a computerized system. Sure, we could build a system where if somebody was rude on the road, you could snap a quick photo of their licence plate, or say it into a microphone or cell phone for insertion into a reputation database. But people could also just do this to annoy you. There's no efficient way to prove you actually were there for the rude event. The photos could do that but it's too much work to verify them. The darts actually do it, since you could not just stick them on my car when I'm stopped, or I would pull them off before driving.
One problem I want to solve with such a system is the selfish merge. We've all seen it -- lanes are merging, and the cooperating drivers try to merge early. Then the selfish drivers zoom ahead in the vanishing lane until they get to its end. And always, somebody lets them in. Selfishly zooming up does get you through the jam faster, but at the same time these late mergers are a major contributor to the very jam they are bypassing.
We'll never stop people from letting in the drivers, and indeed, from time to time innocent drivers get into the free lane because they are not clear on the situation or missed the merge.