Perhaps it depends on the stickers. I have three: "Last time we mixed politics with religion, people got burned at the stake."
"Humans aren't the only species on earth--we just act like it."
And, "Free the Colorado." I also have a decal for World Wildlife Fund. I don't have road rage.

I would say that bumper stickers are generally a method of spreading one's view of the world. Most of the time they are designed to confront and challenge someone else's. Certainly aggressive, though perhaps not physically.

Judging by the amount of bumper stickers on the road and the general lack of rage (at least where I live) I do wonder whether this is purely an academic exercise. Or whether the word "rage" is being applied a little too liberally.

My car, by the way, has none.

That's silly -- perhaps if there are a lot of political bumper stickers -- but my kids have plastered on skateboard brand names -- Vans, EMerica, Zero, Adio, Fallen, do those count? :)

Retired Police Officer here and graduate of Northwestern Traffic Accident School. Road Rage... There was a time that vehicles could be pulled over for following too closly. Rule of thumb was one car length for each 10 miles per hour. This was lost as many court cases found in favor of the driver as the Officer could not prove that the vehicle was following too closely as it was a judgement call. Soon after, many road rage occurances started as drivers in front had vehicles so close behind them that it looked like the vehicles were in their trunk. eg.. the behind vehicle were real close at high speeds and still are today. The front vehicle was, is upset that a possible accident could occur at any time if one had to brake suddenly for wild animals, others cars, other things. Many went out of their way to do a quick brake, put on emergeny blinkers, other things to get the back drivers to "Back Off" Of course common practice became giving the middle finger.... etc. Road Rage as we know it now stems from this. On freeways there are 10 cars almost bumper to bumper at high speeds. This is not good. The Back Off sticker is taken wrong in most cases. It really means, please back off and make it safe for both vehicles. But, it looks harsh. Another sticker should be made with more gentle words. "Back Off Please - Dangerous" What is really needed is a consolidated Driving Laws for all states. It needs to be the same in all states. A driver does not know the laws of a state when he/she crosses a state line. There are no hand outs at the state lines to stop and read. When a driver gets pulled over out of state, this is a huge start on Road Rage. There are ways to reduce "Road Rage" thank you for reading. Major Dennis Kuecherer