. . . You still need to cut in (East) to the official route to cross the Columbia unless you brave the Astoria Bridge which is scary when cars / trucks lose patience with you.
The Astoria bridge is a daunting prospect, but not for the traffic. There is adequate shoulder to ride on the bridge and when we rode it (tandem and bob) we had no issues with the traffic, and they had none with us. More problematic is the onshore wind that can be a little rough as you try to stay in your lane - the side wind makes navigating a loaded bike a little tough. Southbound the first 3 miles are relatively flat, but at the rise for the ship channel, the grade bumps to 6+% and that part really puts you up in the wind. Once you're over the top, simply take the lane and make the horseshoe onto Oregon terra firma and you're good. The seagull that hovered about 6-8' up wind had me concerned that it might target us but guess we were lucky - no white splats sent our way. You can do it - just be careful and pay attention.
Santa Rosa, CA