Driving in Italy is different.
What passes for normal traffic flow in Italy would be considered incredibly rude in the States, even in Chicago. The way it works is this:
The pipe is of a certain size, and it allows a certain quantity of traffic to go through the pipe. The Italian way is to use as much of that space as possible, meaning that motorcycles and scooters split lanes, and are highly skilled at squeezing through a gap that is the width of their vehicles plus 3 centimeters. Cars also inch forward and will even scoot a few wheels over the curb onto the sidewalk. This is normal. I did it at least twice.
Rather than think that these people are cutting in line, or not waiting their proper turn, the Italians take the position that these lane-splitters and curb-drivers are actually making traffic better, as they squeeze through the pipe.
Furthermore, Italians will stop at the pasticceria, double-park for three or four minutes to grab a few cannoli or whatever on their way home from work. This would enfuriate Americans, but since every Italian knows that at some point in the next week, they'll do it too, it all passes for naught. So what if a four-lane goes to a three-lane? We'll make it work, and only a complete buffoon would double-park exactly across from another double parker. Point is, the system works because everyone is part of the organism that is traffic flow, not a million individual steel rooms, each containing the center of the Universe.
It all gets down to taking it personally vs. letting it go. Americans look with anger at people who go for the gap, taking as a personal affront and a virtual middle-finger salute. "In your face, person behind me," we imagine them saying to themselves. It's incredibly narcissistic to think that anyone gives a rat's arse what you think of them and their driving. Here's news, American drivers...it's not all about you, it's about the flow.
Frankly, I found driving in Palermo (and Catania and Napoli and Roma) to be just fine. The rules of the road may seem rude, but they are not rules, they're suggestions, and so long as everyone knows the suggestions, everything goes just fine.