So the roads are infested with bad drivers, it turns out. Many times hath my gentle spirit been moved to correct, oh so reluctantly, the peccadillos of my weaker brethren upon the road (the infirm, the lame, the demon possessed) with an exhortation and the indispensably expressive aid of Motorist's Sign Language.
And yet there are many fine drivers who deserve to be recognized. People who drive well. I see them once in a while. I try to push a "well done" vibe at them, but this concept is unfortunately difficult to convey in the somewhat... emphatic vocabulary of the otherwise comprehensive MSL.
I therefore propose a simple social reward and punishment system. All drivers get to rate other drivers. Your rating floats above your car in glowing block numerals. If you don't like another driver, dock them a point. If you do like another driver, assign them a point.
After a while, people will be able to see bad from good coming at them from waaaaay off. The social stigma that accompanies a low rating might pressure some to improve.
Or not. But who cares, because the best part is, if you have a surfeit of points in your rating, you can use them to buy poetic justice. Thus, when I come up behind you in the fast lane and you do not move over to let me by, I will dial up a rain of earwigs upon you, and you will turn your wipers on high, and it will avail you not. A river, a swarm, a plague of them will pour through your vents and windows, fall wriggling into your hair, teem down your shirt, seethe into your nethers, and they will BITE YOU ON THE ASS.
The accident rate will assuredly go up, but happily my sense of driving satisfaction will rise with it.
AUTHOR'S NOTE: Some yucksters will no doubt jest that my own driving might rate a very low score indeed, thus inviting hilariously ironic consequences upon myself. This cannot be the case, for two objective reasons. First, my driving is beyond reproach, a fact that fuels the fierce pinprick hearts of all the myriad stars that writhe within the vast abyss of space. Second, it's MY system, and I can quickly translate that into Motorist's Sign Language for you if need be.

How about special minimum carma lanes? Like carpool lanes, but for people with humongous driving ratings?
You know, with the LCD overlays being built into the windshields of some luxury cars these days, this could one day become a reality. It would be just like driving online. ...weird...
Why stop at earwigs, forsooth? Call down the ten plagues of Egypt, culminating in the slaying of their firstborn...maybe that'll get them off the road, or at least out of the left lane long enough for the rest of us to get somewhere.