Johnny T's NYC Tourist Tips: Get Outta The Way, You're A Jerk
^ 1) Slow drivers and those who brake w/o reason (aka many old people, some teens, and anyone else who fits the bill) (See 1:22 "there's two speeds in NY...move fast, or get outta the way"

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2) Contrary to #1, those who drive fast/crazy during a snowstorm....you pose a risk to the rest of us!
3) People who don't use turn signals. This one makes me crazy. I am not a mind reader.
4) people who use brights after you flash them, and/or HID/xenon/LED lights. I've driven cars with them and I don't find them to be much more advantageous than regular lights when driving, and when they're facing you at night and youre tired... theyre very distracting. (though they do allow for cool car designs: i.e. Audi)
3) people who litter (cigs, mcdonalds/local deli meals etc). This is huge, because although I love cars, I also care very much about our earth, and it saddens me that people are so willing to obliterate it.
4) People who cant make up their mind while driving, are utterly oblivious, and/or under the influence.
5) People who stop too slowly or to abruptly
6) People doing stupid, crazy maneuvers (looking at the driver next to you if you forgot you needed to get into the turning lane, and then, subsequently squeezing your way in is one thing..... driving 60 in a 30, stopping to a halt, and squeezing your way between a line of cars that's piled up in the straight lane where they're almost blocking the turning lane, to almost hit the car in front of you when you stop and cause a pile-up is different)