I have lived in a lot of places.  The drivers in Texas drive really fast and can get aggressive in a moments notice. The ones in California are constantly changing lanes, zipping in and out in search or a commuting edge.  And ignoring the HOV min passenger requirements too.  In Portland, drivers are pretty courteous.  They don't zip in and out of lanes, use their blinkers and are not aggressive.  They also have terrible congestion because of lack of infrastructure (worse than Denver) and they are overly cautious so you get stop and go traffic the moment anyone pulls to the side of the road and stops.