I find that Oregon drivers in general are among the worst - well, my comparison is with California, Alabama, and Tennessee. OR drivers are generally asses when it comes to interacting with cyclists.

As to trucks, my observation has been basically that anybody getting paid to drive a daily delivery - logging truck, FedEx, school bus - is a danger, they are in a hurry to get done what they need done. Brewster is a here-to-there road, folks are generally in a hurry between towns on that road, and frankly I would find a different route. I worry less on the connecting roads, though most of my riding is north of Albany and to the west of 99W. The riding out around Lacomb is nice, but you sure have to be committed to "sharing the road" with the cars that own it.