Pennsylvania drivers annoy me. Actually, they more than annoy me but I'd rather keep this on a nicer note and not use the words I would normally use. In all honesty, it's probably not just Pennsylvania drivers as I'm sure all states have the same idiots.
One of the biggest things that I encounter is the "NASCAR Driver Syndrome" -- well, that's what I call it anyway. This is the guy, woman, kid, old man, old lady who watches NASCAR way too much and thinks that their daily drive is on a track. You're driving along, see a car stopped on a side street waiting to get out, and they will almost always whip out in front of you with almost no space left. A quick look in the mirror shows that there is nobody behind you, so this person could have easily waited another 2.5 seconds and pulled out behind... but they didn't. Why not? I believe it is because they NEED to be first. The desire is to get in front, just to have "beaten" you. Of course, it almost always works out where you then need to slow down since once they are in front, they can't seem to get out of their own way.
The next driver on my list is the "On And Off Driver." This is the driver who will come from behind, drive right up close, and then back off... only to repeat this over and over. I get it, you're in a hurry but what can I do? The car in front of me, holding me up while you're on and off my bumper, doesn't seem to care that you're in a hurry. This is not only annoying but incredibly unsafe as well.
How about the "Highway Idiot" who will be going 60mph in a 65mph zone, but when you pull out to pass them, they suddenly take offense that you are doing this. Since you are challenging them, they need to suddenly speed up to keep you from getting in front of them. If you continue to go faster, so do they. If you back off and pull back in behind them, they then go back down to 60.
The last one that gets me is the "Double Yellow Speeder." This is the guy who decides that you're going too slow, and he's in a great hurry. Keep in mind that "too slow" is usually still about 10mph over the speed limit. He will come up behind you, do a few fancy in and out moves to test the double yellow line, then he will fly out and pass you in all his ultimate coolness. I need to point out that the cars in these cases are almost always some loud piece of... well, you get the idea. So they pass you and they're all cool but within seconds, they are behind the car that was just up the road in front of you... who also has 4 or 5 other cars in front of them. Even with the ultimate coolness, you wind up catching up to them and riding behind them for the next 12 miles, so what did they gain really but putting their and your life at risk? Well, they got in front of you!
So that's pretty much it. There are, of course, other things that annoy me on the road but these are the ones I see on a weekly basis. I almost always encounter these 4 types within the 5 days that I drive to work.