I still see lots of people who are willing to disregard these signs, though. For example on Channing at Roosevelt I see people cut through daily.
https://www.google.com/maps/@37.8647438,-122.2756017,3a,75y,...
https://www.google.com/maps/@37.8647438,-122.2756017,3a,75y,...
Clever use of one-way streets and stop signs also helps, and effectively reduces the load of cars moving through the neighborhood at high speed to just the white ones with blue lights on top.