Sure, but the 2 major components I can think of -- building more housing that would use that freeway, and shifting trips from transit to cars -- are not things

Sure, but the 2 major components I can think of -- building more housing that would use that freeway, and shifting trips from transit to cars -- are not things that are likely to happen with trips from the Peninsula to Marin, where there are no transit options, and where housing is already restricted.