When another driver does something really dangerous and ill-mannered on the road, like cutting in millimetres in front of you or overtaking on a pedestrain crossing, do you spend the next half hour dreaming up methods of delivering comeuppance? I do.
My own preferred method would involve no road rage but simply getting out at the next red traffic light, calmly tapping on the window of the car and telling the culprit that I am the seventh daughter of a seventh daughter gifted will infallible predictive powers and that I am very sorry to have to inform him that I have just seen him die a horrible death. It's petty, I know, and needless to say I would never do it but just imagining the scene is catharsis enough.
Fictional characters are more foolhardy and I suspect that novelists sublimate their own revenge fantasies through their characters. Remember the Ann Tyler character who got her own back on a hapless old man who had committed some highway misdemeanour by later speeding past him and pointing wildly at his tyre just to cause him the inconvenience of stopping and investigating? The ploy backfired though, I can't remember exactly how, and the character ended up having to run the man home to his family.
A character in a short story by William Boyd that I read yesterday delivered the following line to a man who had stolen his newspaper, "Next time you have a piece of bad luck, think of me. Because I will be thinking of you." I quite liked that.