San Francisco Muni LRV (Light Rail Vehicle) 1243, built in 1979 by Boeing, is eastbound on Duboce Avenue at Church Street, on the N-Judah line, on March 24, 1980. As its <a href="https://en.wikipedia.org/wiki/Rollsign" class="extiw" title="en:Rollsign">rollsign</a> shows, it was en route to Embarcadero Station, through the then-new "Muni Metro" light-rail subway, the portal to which (for routes J and N) is located just behind the photographer.  At the time of the photo, the Muni Metro had opened for passenger service only five weeks earlier (on February 18, 1980), and the N-line was the only line using it (and using it on weekdays only). All four other streetcar/tram routes were still using <a href="https://en.wikipedia.org/wiki/PCC_streetcar" class="extiw" title="en:PCC streetcar">PCC cars</a> at all times and running on the surface of Market Street through downtown.  Although the Muni Metro did not open until 1980, the Boeing LRVs had first run in service in April 1979, on a K-line shuttle service operating only on the outer portion of that line.  The tracks in the foreground were for the J-Church line, and car 1243 was also crossing trolleybus wires for route 22-Fillmore.
<a href="//commons.wikimedia.org/wiki/User:Steve_Morgan" title="User:Steve Morgan">Steve Morgan</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>