I can't speak to Arizona, but I lived in CA for 6.5 years and in IL for almost 4 years and Illinois drivers are worse than CA drivers and it isn't even close. IL drivers are the most selfish drivers I have ever seen - never have I been anywhere where they pull out into the intersection when the light is changing even though it is blocked ahead and they can't get through, blocking the intersection for the cross-traffic. IL drivers think that if they can get ahead of one or two more vehicles that will make all the difference in the world in their commute, whether that is forcing themselves into the intersection, passing on the right shoulder/where there isn't a lane, not merging until the last second, you name it. In CA everybody knows there is traffic everywhere and they, for the most part, just deal with it and take their turns. (CA also had legitimate road rage incidents, and I think that has made people think twice about being a jerk.) The ones that drive in AZ are horrible. They do everything you are describing what IL drivers do but multiple that by 10. If you are traveling on the I-10 and merge onto I-17 you have to watch out for the CA drivers returning to CA as they sit in the right lane that is an exit only lane for I-17 and wait until there is nothing left but a huge break down lane or worse they stop completely in the exit lane that is going at 55mph or faster so you can merge onto I-17 at a decent speed. They are also driving at about 25mph or slower so they can merge. There are 3 lanes plus a HOV lane which they already have 2+ people in their vehicle and are not driving in the HOV lane. Makes no sense.