Doug, and others, the wonderful irony as all of you who have toured, is that biking on a superwide shoulder like this (even if "illegal") can be 100s of times safer than sections of narrow, curvy two laners with the edge of the road being perhaps where the white line is in Dougs photo. Rough gravel shoulder an inch off the white line, trucks coming in both directions going a bit over the speed limit-lets say they are going 55 or 60, with no room for them to move over if there is an oncoming truck.
Throw in some gusty sidewinds and there you have it, a situation that is potentially pretty darn serious and requires us to be ready to bail to the side in the blink of an eye.

Chosing a route on bike can certainly involve a bit of luck, a big highway section like in Dougs photo can or cannot be unavoidable, but not necessarily horrible. A nice looking small two laner can look fine on paper, but can be super busy, or have a rock quarry nearby or be the main route for all the logging trucks, so can be pretty darn unpleasant, or unpleasant at a certain time of day or day of the week.

I guess what I would suggest other than the previous ones, is to try to use the internet to get an idea from other bikers of how a given route is.

(and now my public service announcement)--and please use a mirror, it'll give you a few seconds heads up in a "perfect storm" situation that could really make a difference.