Not usual, IME they’re rare. I called SF 311 and requested such a sign at an intersection where people often seemed to be confused (10th and Moraga in the Sunse

Not usual, IME they’re rare. I called SF 311 and requested such a sign at an intersection where people often seemed to be confused (10th and Moraga in the Sunset, IIRC). To SF’s credit, they reviewed the accident history at the location, and a traffic engineer called me back to explain that 1) they did not see a history of accidents there and 2) they don’t like to use too many of those signs, because they don’t want people to assume that the intersection is an ‘all way stop’ if the sign is not present.