Sidewalk street name marker plaques, Market Street in San Francisco. These were likely installed in the very early 1970s, as part of the re-covering of Market Street following the construction of subways underneath it.
The all-caps lettering appears to use Chelmsford, a copy of Optima that’s distinguished by the stroke extension at the top of A. According to Mark Simonson, it was “produced by Addressograph-Multigraph (AM) in the seventies for their phototypesetting machines.”