The lack of shoulders is VA seems to be problematic. The number of times I've had to ride a 4-lane for a mile or so (to jump from one wonderful country road to another), only to find no shoulder, or just as often the road was repaved and the shoulder was left only passible with a full-suspension bike and a lot of swearing, seemed to be the rule. And the 4-lane was heavy, very fast traffic. Often I've ended up pushing the bike well to the right of what once passed as a shoulder.
The worst story I have heard was from an old spark a couple of years ago. She commuted to college in Boston by bike. One day she was struck in an intersection. While laying in the middle of the road with her mangled bike, some *&^%$% was honking and yelling at her to get out of the way. She ended up in the hospital for the night, and it took her months to mostly recuperate.
As for CO, there are easily two different Colorados. The most disturbing is how often I have heard the "N-word" in western CO, after almost never hearing it in the modern South. I will say from my experiences hiking out here, I feel the mountain biking community may be the most curtious I have seen - they almost always yield the right-of-way to hikers.