contango 

Depends on the situation and how likely I think it is they're going to escalate. Sometimes I just ignore them, sometimes I wave (with one or more fingers visible), sometimes I'll shout right back at them.

Had a priceless one today where some silly woman was angry at me for staying to the right of the lane rather than using the cycle path to the left. The fact I was turning right 100 yards ahead seemed lost on her. She must have got to the red traffic lights a full 10 seconds ahead of me, and must have been glad she got to spend those extra seconds waiting at the light rather than waiting behind me. When she said I should start paying taxes I literally howled with laughter at her, before waving goodbye to her as her light turned green.

Wut

I cannot believe someone would really say that. Just because you ride a bike means you do not pay taxes? Wut.

Myosmith

Doesn't do anybody any good to return the rudeness, it just increases the chances of the situation escalating or the driver taking it out on the next cyclist he/she sees.

sudo bike

Generally, I just either ignore completely, or smile and wave. If it is a more direct confrontation, like at a stoplight, I might get more creative (a few responses stolen from here, actually).

My personal two favorites are:
"You're not in a car, buddy!"
*looks around* "Holy crap, you're right!"

or

"The lane is for cars, man!"
*mime rolling down window* "Sorry, the window was up, what was that?"

But generally, I get yelled at so rarely I don't get the chance to trot them out all that often.

contango 

She was probably agitated that I didn't pay road taxes, despite the fact that cyclists pay the same (zero) as other low-polluting vehicles like the G-Wiz and the assorted bubbles that run forever on a thimbleful of gas.

Astrozombie

Dude i've gotten so used to this being the "rocker" kid back in the day, being the guy with long hair so when i really started commuting by bike it wasn't a big deal. It doesn't even really startle me anymore when people decide to get cute. Always remember to dig in and keep striving for your goals, haters will stay back in life and continue to hate because they hate their own lives. I did think though that if i commuted on a $1K bike it would be freakin hilarious if some fat person in an old crappy car was talking smack, i could say "This bike is worth more than your car and bikes were on the roads before cars, now go get a slim fast"
The opposite of love is not hate; it's indifference

Worknomore

I had the long horn blast, fast/pass yesterday while taking the lane on a 5 lane. I caught the lady at the light 30 seconds later and said "If I were driving my car you still would have had to move over to pass me" Much to my surprise she replied "ya know you are right, sorry"

blackvans1234

Just keep spinning, just keep spinning, just keep spinning spinning spinning....

dynodonn 

Keep truckin'......like the doo dah man.

PatrickGSR94

wnl256

I either ignore it, or I wave back and yell "thank you". Generally the driver has no idea what to do with that response.

FBinNY 

There are times I really wish I knew ASL. I'd love to sign back to some of these guys "f*ck you, I'm deaf". Of course they probably couldn't read it anyway, or I could pretend sign anything but it wouldn't be the same. SDome folks get flustered when they find they've been yelling at a deaf person.

Booger1

I tell my mom to quit following me....

leob1

That about sums it up, both the comment and the link.
Just start laughing because it is funny that they think you can hear them.

jowilson

Most of the replies on here give cagers a reason to not like us cyclists.

PlanoFuji

Referring to fellow human beings by terms like cagers does the same thing...

jowilson

So you agree?

Chris516

Provide proof of your assertion.

jowilson

Ask and you shall receive:

"I stop right in their way and ask them what's the matter.
They're in a hurry so I slow 'em up."

"sometimes i flash the peace sign!
sometimes, just half of it."

"I cuss them out flip them the bird and everything else that makes me happy"

rydabent

It depends on my mood. I may ignore, smile and wave, or indicate what I think their IQ is by one raised finger.

dougmc

The first part is probably ideal.

The second, not so much ...

Ultimately, if you're not going to do something like apologize (which will usually throw them off guard, but in a good way), the wise thing to do is nothing -- ignore them.

By responding with a middle finger or insult about their mother even an argument about where you should be riding -- you're almost certain to not be educating them. Instead, you'll be doing something somewhere between annoying and enraging them. Which they may then take out on the next cyclist they encounter -- or they may take it out on you. Remember, they've got 4000 lbs of steel and 130 hp around them and you've got 30 lbs and 0.3 hp (give or take.) A physical confrontation is very unlikely, granted, but if it does happen, and it involves their car being used as a weapon, you aren't going to win -- at best, you'll break even and escape.

If they're yelling at you when you didn't do anything wrong, they've already established that they're douchbags. Might as well not find out if they're psychopaths too.

Ultimately, no matter how good your zinger is -- it won't make things better, and it might make things worse.

That said, there's a small chance for constructive interactions, but it never involves yelling -- it generally happens when you're both stopped, next to each other and their window is open. Anything else, and there just isn't time -- and if people can't really hear you but know you said something, they often just assume the worst.

Keith99

Honestly this rarely happens to me.

Being 240 and wearing a beard makes a difference.

BUT the last time I recall an incident it was when I came down a short steep hill and on the runnout just as I hit this ugly cloud of dust kicked up by some gardeners with those darn blowers a car behind me lays on the horn. I gestured in the Italian style, not quite a finger but still a bit of rude and a bit of saying what's wrong with you.

The car pulls up beside me at the next stop sign and the passenger says 'You were fine, it was those idiots with the blower'.

So now I'm a bit slower to decide the car is my enemy.

Time before that some tools threw bottles in front of the group I was with, spreading broken glass all over the right part of the road. They were not happy when they realized I was trying to chase them down and fled like scared children.

Chitown_Mike

This is a great response, and I would add (from my personal experience) that most people are overworked and stressed. I ride the same roads I drive when I commute and I can tell you at certain points, after being behind the same old lady in the Volvo doing 10 under, the same soccer mom on the phone and smoking, and the same young thug in his loud WRX that things get on people's nerves, especially little things in traffic. Lord knows I get rather antsy at times when driving.

I see how people can react to each other and I see a lot of the same people both in the morning and evening commutes and I realize that while they may not know me on my bike versus my car, I know them and if I am rude on my bike because they are/had a bad day what justification does it do that I know become a d-bag on a bike that they see several times per week. The only time I yell is to garner their attention to the fact they are about to hit me, and that is done without swearing or name calling. Usually a, "Hey! PAY ATTENTION!" works and they realize their mistake and are usually apologetic. Sometimes not so much but I need to not worry about them but the other dozens of cars around me.

I will tell you commuting can be humbling. I have seen several people look so hurt and forlorn sitting in cars in a mile of traffic as I pass by knowing that had I been in my car I might be in that same position. So my resentment of certain individuals bias or poor driving abilities is set aside when remarks are made because it isn't that important. Best part is there are more people at my work, and friends that I don't work with, that started commuting because I encouraged them to.

Rewind earlier this year or last year and I was a bit different out on a bike, but when I paid attention to the other people around me, I realized their negative reactions were because of me or a bicycle, but what hand life is dealing them and I am a soft target to throw their frustrations on to.

spare_wheel

I believe that ignoring bullies only empowers them. So for me the risk of not responding is greater than the risk of responding.

spare_wheel

Sorry but I do not spend much time worrying about the hypothetical emotional state of an irrational minority.