You missed the glory days of the PCC's in San Francisco. In the mid sixties they operated much faster than they do now. It's kinda ssd to see how slow they trundle on Market Street these days. There are so many automobiles.

Historically it seems that after the failure of the streetcar subway bond issue in 1936 or 1937 SF gave up on modernizing the rail system. The Market Street Railway lines were wholesale abandoned after the war and the flagship B line was a victim of urban removal in 1956 that wasted the Fillmore District and turned Geary Street into a quasi freeway.

My old friend in Muni told me that Muni management in the mid 50's wanted to bustitute the Twin Peaks tunnel but it was deemed too narrow to be safe, altho the Sunset Tunnel was found to be wide enough for buses. The J line on Church was saved because the neighborhood fought for it. Luckily Muni was able to secure PCC's from Saint Louis in 1957 on a lease-purchase deal that got around city charter limitations. The carmen's union had insisted on 2 man operation which played into the hands of the bus crowd.