San Francisco isn't planning to do it. We've done it. There's really only 1 freeway crossing the city left (I-80/101).
This what they wanted to do until the citizenry revolted:
The Embarcadero Freeway was the most brutal, ugliest part of the plan that got built before the people got organized to stop it. Even it was brought to a dead end:
Above 2 images:
http://www.preservenet.com/freeways/...barcadero.html
More Embarcadero nastiness shown cutting off the iconic Ferry Building from the city:
https://www.pinterest.com/pin/56224695318650503/
But they never were allowed to finish it:
https://www.foundsf.org/index.php?ti...Freeway_Revolt
And after sustaining damage in the 1989 quake, it was torn down and now we have:
https://www.dreamstime.com/photos-im...dero-road.html
https://www.google.com/search?rls=en...jHJCQbxuLXNeLM
Similarly, the Central Freeway was first dead-ended by the "freeway revolt" and eventually torn down after quake damage:
https://oewd.org/octavia-blvd-project
became
http://www.saitowitz.com/work/8-octavia/