“Putting three lanes of heavy northbound traffic on Western Avenue will devastate the blocks between Western and Alaskan Way. The streets will become completely unfriendly to pedestrians. Street-level retail will wither and a block-wide dead zone between Western and Alaskan will face the waterfront…
“The solution to the future of Alaskan Way needs to be an urban solution. There are many cities worldwide with successful urban waterfront boulevards. A study of such spaces will show that a six-lane boulevard can be accommodated along Alaskan Way.”
The best solution for the viaduct is a two-way boulevard. End of story.
And there are many, many ways to design an urban boulevard:
[ Grand Boulevard, Barcelona ]
[ Champs Elysees, Paris. Five lanes in each direction, but that doesn't keep the pedestrians away. ]