For nearly thirty years, Streetcar Line #17 rattled over 20th Avenue from Lincoln Way to Wawona, but it's been over twice that time since it faded into history, so let's hop aboard our Time Machine and take a ride on Line 17, from the Ferry out to the Zoo and back, just as one might have done 70 odd years ago.
But first: a little history...
United Railroad's Line #17 "Haight and Ingleside" opened on 17 February 1916, providing streetcar service from the Ferry Building via Market Street, Haight, Stanyan, Frederick, Lincoln Way (over the already existing #7 line), 20th Avenue (over the already existing Parkside line), Wawona, 19th Avenue, Sloat Blvd., Junipero Serra Blvd., and Ocean Avenue to Miramar Avenue.
After the opening of the Twin Peaks Tunnel in 1918, and the extension of Muni's K line over Ocean Avenue first to Miramar, and soon afterwards to Brighton and Grafton in 1919, United Railroads cut back Line #17 to 19th Avenue and Sloat Blvd. since their own #12 line already covered the same territory. However, on Sundays and Holidays, Line #17 now turned West on Sloat Blvd. and used #12's trackage to take riders to the San Francisco Zoo, a popular destination.
In May 1937 the Golden Gate Bridge opened, and 19th Avenue was selected to be widened and designated U.S. Route 1 leading to the Bridge from points South, so in December 1937 service on Line #17 to the Zoo was brought to a close, and Wawona and 19th Avenue became its new terminus, thus freeing 19th Avenue for four much needed lanes of automobile traffic through the Sloat Blvd. intersection. In the meantime, Muni's Line L had been extended, in September of that same year, to provide service to the Zoo over the 46th and 47th Avenue loop, still in use today.
In May 1944 the Municipal Railway took over operation of the former Market Street Railway, which had been operating Line #17 since its own takeover of United Railroads in 1921, and the end of service on this particular line was only a matter of time. Line #17 had always been a duplication of Line #7 as far as Lincoln Way and 20th Avenue, and, since 1942, Muni had been operating their own #3 Motor Coach line on 19th Avenue, just one block to the East (renumbered line #28 in 1949). However, at least on Sundays, #17 still filled a need, as throngs to and from Sigmund Stern Grove filled the cars to capacity on a regular basis.
During the last few months of its operation, Muni experimented putting Line #17 on Mission Street from 12th to the Ferry, instead of Market, but this only confused riders, added to the already overloaded streetcar scene on Mission, and service was permanently abandoned on 22 December 1945.