Around here, it's really a trade-off. If you want a decent shoulder, it's usually a 50 mph zone with more traffic. If you want a country road with less traffic, there is not a shoulder at all. I actually prefer the roads with no shoulder and less traffic. The speed limits on these roads vary from 35 to 55, but driver's seem to not worry as much about "limits" on these types of roads.
There are only a few intersections around here I avoid, and the reason for the avoidance is that my bike doesn't set off the light, so I have to run the red to turn left and the cross-traffic is usually heavy.
I definitely would sacrifice time and distance for safety. Do it on just about every route I ride.
Some cities around here have recently started putting in some bike lanes. But I don't see drivers treating them any different that a regular shoulder, and the bike lanes usually just collect road debris and gravel.