One extreme approach to that would be to pick some line in western SF neighborhoods, close all roads west of it, declare everything west of that a park, and rer

One extreme approach to that would be to pick some line in western SF neighborhoods, close all roads west of it, declare everything west of that a park, and reroute Highway 1 slightly eastwards. And compensate people affected by the change. Or close that to regular car traffic but keep SF Muni buses and trams and maybe high-occupancy taxis/ shuttles/ rideshares.