Do you think it could have to do with the construction of the road as well? I know the autobahn has something like 27" of concrete below the asphalt and they have a really strict maintenance program there. I think the CA roads (like most in the US) have 11". If we all drove our heavy trucks and trailers faster on the US roads it may play into the roads early destruction - potholes. Makes me think that is why the CA roads are so bad - we are all driving really fast on them and they can't/don't keep up with the maintenance. Plus there are so many more people driving vs more rural states/roads. If CA were to allow a higher speed, they would also have to repair the roads more and faster - $$$$$. I am sure there are a lot of factors that play into the reason. We could probably ask a legislator if we really wanted to know all of them.