I started riding in Minneapolis about 4 years ago, and I would say that this is probably true. Cars just behave better around cyclists than they did when I first started. I still get the occasional "I didn't see you" and impatient tailgating dickhead that refuses to pass when they have plenty of room, but for the most part drivers are pretty patient and more careful than they used to be. Intentional acts of intimidation/endangerment by drivers have gone way down.