I think you have to pick one or the other, traffic or curves. Interstates will eliminate most curves, but will add to the traffic. Going off interstates means curvy roads. Taking 35 north to 90 is an alternative, there are some roads I've taken to avoid OK that are pretty decent. How about taking 81 or 281 north to 80 and then west on 80 to 84. Boise was pretty rough when we went through but they had construction then, a couple years ago. And 84 is pretty good, only one bad grade going into Pendleton.
