I lived in Portland 1980-1994. Replacing the I-5 bridge to Vancouver is absurd! The roadway going to the bridge on the Oregon side has finally been upgraded to match the bridge. It is time for the westside bypass. The new bridge would cross the Columbia at St Helens or Columbia City. Somewhere in that area anyway. The road could follow Cornelius Pass Road to TV Highway. Most of the right-of-way land is undeveloped and could be purchased cheaply. The bypass should go somewhere between Sherwood and Newberg. The bypass would connect with I-5 somewhere around Woodburn. Advantages: 1) Northbound I-5 traffic goes around Portland. 2) Westside traffic going North does not have to go on the Sunset Highway through Downtown Portland. 3) The west side will need a bypass in the future, a majority of the land is not currently developed 4) the bypass could be built in stages as roads exist over most of the route.
All we need is a bigger bridge on I-5 at Vancouver. Are we going to double the number of lanes feeding the bridge? What does it cost to double I-5 from the Columbia river to Wilsonville? We do not have enough power in Washington DC to ever make that happen in our great-grandchildren's lifetime.
Plan the Westside bypass, build the missing pieces (such as the bridge over the Columbia), and acquire land for and upgrade the roads. Our money will go much further this way - rather than tearing down and rebuilding in an urban area!