Huh, I don't like 99W very much, and the shoulder is bound to be pretty gritty right now.
Consider swinging over to the west side (Hillsboro) and then:
Fern Hill Road
Spring Hill Road
North Valley Road
...which puts you just east of Carlton. Abbey Road will take you into Lafayette. Or, you can head west on Carlton-Chehalem road and drop down from the north at your leisure.
Go to maps.google.com and look in the vicinity of Yamhill and Carlton to see the roads I'm talking about.
ORS 811.065 (1)(a)
The driver of a motor vehicle may only pass a person operating a bicycle by driving to the left of the bicycle at a safe distance and returning to the lane of travel once the motor vehicle is safely clear of the overtaken bicycle. For the purposes of this paragraph, a “safe distance” means a distance that is sufficient to prevent contact with the person operating the bicycle if the person were to fall into the driver’s lane of traffic....
LCI #2105 Lambchop Rides!