just try some deep breaths...
When I was still living in Rochester, I was riding home for lunch one day, and I had a guy come within inches of me, the road merged, he sped up and nearly sideswiped me just to get in front of me at a narrow section of road. I was visibly upset, throwing my hands up in frustration, I could see him looking back in his rearview at me. He had to slow down right away anyway because someone ahead was turning left, so as I rode past him on the right side I yelled into his open window, "MORE ROOM PLEASE!"
After he broke free from his position in line behind the left-turner, he chased up next to me, real close, and started yelling back. I tried to explain (while riding next to him) that I need at least 3 feet for safety, it is state law. He sped in front of me, slammed on his brakes, and then pulled over up the road in front of me. It happened to be right in front of my house, so I stopped anyway to get off my bike and walk up to my house. He got out of his Audi with his pleated khaki slacks and golf shirt and stormed right up to me and got in my face.
“what’s the issue here?!”
“you’re too close to me, I need more room if you are going to pass me,”
“YOU NEED TO GET OUT OF THE ****ING ROAD!”
“if you look up the traffic law, you’ll see that I have the right of way, and that you are required to yield or give me room,”
“WHAT YOU WANT TO DO SOMETHING ABOUT IT?!” (he then tries to psych me out by pretending to headbutt me, or whatever you call that. I didn’t flinch).
“I am a vehicle on the road, I have the same rights as you.”
(he was saying something else, but around this point he decided to just spit in my face)
I was dumbfounded for a second. Did he actually just spit in my face?
“That’s really mature.”
“YEAH, YOU BETTER WATCH YOUR MOUTH BECAUSE YOU’RE GOING TO GET YOUR ... KICKED!”
At this point he was walking back to his car, obviously realizing that I was not going to back down and that I was not intimidated (I am a 5′10″ 220 pound viking, I don’t scare easily).
“Have a nice day sir, drive carefully”
And I walked towards my house. Just as I got to my door, I realized that I should have gotten his license number, but I was still too amazed that I had just had that encounter. He had peeled out and disappeared. The whole moment lasted about 30 seconds. I hope he realized that the couple seconds he might have saved by passing me ended up costing him an extra minute or so by stopping to try to pick a fight with me.
But anyway, point of the story is, He was the Jerk, and then I was the Jerk too, and I escalated the situation. I still kept my cool and didn't let him get me involved in a physical altercation, but at the same time, I could have just let him drive away without trying to "educate" him on traffic law (like he was very receptive to learning at that point anyway). Now I just pretend the cars aren't there. They blow by so fast around here that I barely even notice they're there, and if they yell something I barely catch a syllable of it before it's out of earshot. When I have close calls, I stare down the driver and let them know I am not happy, but I don't try to make it worse.
I like the idea of peppering the back of their car with projectiles. But we're better than that, right?
. I can quite honestly say I never started a fight, but I never backed down from one either. Every incident I was involved in always ended badly, either with someone getting hurt, or me getting in trouble with the police. Fortunately, I was never charged. 
