I've driven across the country 4 times now, and lived in all four corners plus the middle (New England, Georgia, California, Washington, plus Minnesota/Iowa). In a cold weather state the roads tend to get rough because of the winters. Roads are expensive to maintain there. Never had any trouble at all in Texas or Arizona. Lots of trouble in California, though, and the Dakotas can be rough outside of I90 and I94. Not a function of negligence or anything in the Dakotas, it's just cold.