Yeah, this is not a "slap it in" solution. If indeed it does solve all of these problems. Traffic is gonna get worse before it gets better if you take away roads and lanes. Culture has to shift and people have to leave their cars at home, or really affordable housing and good transit? Thats just gonna supply the outsized demand to move to California's densest areas. So you'll have the same problem, but with lots of new people who don't experience it. Planning has to find people who will change their lives to make all of society better, too.