If I ran the show:

All on and off ramps would be on the right hand side of the freeway.
There would be no four lanes, down to three lanes, down to two lanes.
The Seattle powers were plenty willing to use immenent domain for the monorail now we'd see it used where needed.
Highway 99 would become an actual highway again. No cities or districts would be allowed to add stop lights.
Ferries would pay for themselves which may slow down rampant development across the pond.
I'd wait for the viaduc to fall down then, using emminent domain again, tear down all of the condos and replace it with a much larger viaduc.
Bulldozers would be stationed along the freeways and highways. Blocking a lane you get bulldozed off to the side. Tow them away after rush hour.
I'd discourage and maybe even penalize cities like Seattle and Bellevue who try very hard to concentrate all big business in one area creating commuting nightmares.
Finally, I'd launder, I mean fund, billions of dollars to select friends in order to perform a "feesability study" for development of a Star Trek type of teleporter to, once and for all, resolve traffic headaches, climate change and pollution. Coincidentally the study will be completed about the time I retire.