Here is a list of sociopathic behavior on the part of drivers that I have recently witnessed. Let me stress that I don't think this behavior is unique to Pittsburgh: I think it can probably be found in every area of the country if not the world. However, I call it sociopathic because this behavior becomes really annoying and often dangerous in older urban neighborhoods with narrow streets, many bus routes, stores designed to have things delivered from small trucks, and limited parking.
--Taking up two spaces in a lot.
--Parking large cars or SUV's in spaces marked for compact cars.
--Blocking intersections and busy driveways.
--Not stopping at the stop line. (When they are well back of the intersection, it's usually for a good reason. Or, did you just think the line painter was confused?)
--Not using turn signals.
--Taking up two lanes while waiting to turn left.
--Swerving to the left before a right turn.
--Not yielding to pedestrians at intersections. (How many of you remember from driver's ed that the pedestrian has the right of way at every intersection, not just controlled ones?)
--Honking at a driver who yields to pedestrians at intersections.
--Honking at a driver who does not make a right turn on red when there is a steady line of cars moving through the intersection.
--Honking at a driver who does not make a left turn when there is a steady line of oncoming cars.
(The last two really puzzle me: can the driver behind not see the cars with the right of way or does he/she assume that a good neighbor should commit suicide and/or manslaughter so that the honker can get home faster?
--SUV's with tinted windows. (Ever try to get out of a parking space with one of these next to you? I'm going to have to try to get X-ray vision with my next eyeglass prescription.)
--Gigantic delivery trucks parking at bus stops while making deliveries during rush hour.
Feel free to add your own in the comments section.