When driving, what gets the most in your nerves?

I usually do speed myself, but generally when others around me are too. I guess it's something I got from my summer job as a DHL pickup driver. So on that note in no particular order:

1) People that go flying past me even when I'm speeding. They must have a death wish.

2) People that show off as they go by. Usually it's either the rev of their engine as they zoom by, or sometimes it's some guy on a crotch rocket doing a wheelie for an extended period of time. (Hope you don't see that pothole next time you do that, moron.)

3) Like some have similarly said, driving behind or around 18-wheelers. I had to do that once behind two that blocked both lanes, in the rain, at night. I could not see a thing even with the wipers on all the way, it was scary.

4) People who change lanes abruptly, even if they signal. And on that note, anytime someone doesn't signal when they should.

5) People who don't even look to see if anyone's in the lane they're merging into.

6) People who refuse to let you change lanes in front of them, especially when you have to get into (or out of) an exit lane, or merge from a lane that's ending.

7) People who tailgate, especially when it as a result boxes me in. That makes me really nervous.

8) People who have the gall to make rude gestures or shout crap at you for whatever reason. Use your lights or your horn, moron. That's what they're for. (The horn at least.)

9) Cell phones. The reason for which people have explained well enough before me. You can get pulled over for that around where my parents live.

10) This one I think I got off my dad. People who throw their cigarette butts out the window. Cars have ashtrays for a reason, dude. Heaven forbid your nicotine addiction warrants you having to use that thing for once, and *gasp* maybe even clean it on occasion.

Jam it back in, in the dark.