L-Taraval line (San Francisco Muni Metro) rebuilding

The San Francisco Municipal Railway is rebuilding one of its light-rail lines: the L-Taraval line from West Portal to its end near the ocean. L Taraval - Wikipedia

• L Taraval Improvement Project | SFMTA
• L Taraval Improvement Project Segment A Complete July 2021 | SFMTA - "Construction of Segment A started in September 2019 and was completed in July 2021 on schedule and within budget." and "Our work on this first phase improved transit and infrastructure between Sunset Boulevard and SF Zoo, ..."
• L Taraval Improvement Project - Segment B | SFMTA - "... from Sunset Blvd. to 15th Avenue, and on Ulloa St. near West Portal. Construction is scheduled from ​early 2022 and last through the fall of 2024." -- this page links to pictures that show some of the planned work

So they did the outer part of this line first, and they are now doing the inner part.

To see how much has been done, I opened up Google Maps, Bing Maps, and MapQuest. At the ocean end of the line, at 48th Ave., the MapQuest map had low resolution, while the Google and Bing ones were crisp.

The two tracks merge to one at the end of Taraval St., for a distance of 150 feet. That's long enough for a two-car Muni Metro train. Bing Maps showed it in the middle of rebuilding. Those tracks have don't seem intended for revenue service, much like the wyes that I find in the MM surface tracks that extend into nearby streets.

For boarding the trains, there are several "boarding islands". These are a lane wide, and they alternate between the two sides of the tracks. Bing showed them in construction, while Google showed them complete. With Google Maps's street-level view, I could see them up close: one lane wide, sidewalk height. That mode had an oddity: I went into a crossing street with one of them, and I could see pre-construction Taraval St. -- nothing along the tracks. Continuing eastward, I saw some pre-construction views in Taraval St. itself.

Sometimes there was also a high-level platform, a platform for wheelchair-bound people, on the other side of the tracks from one of the boarding islands. There were also some "pedestrian bulbs" or bulb-outs, corners where the sidewalks extend into the streets.

Then something odd. At 37th Ave., there is a platform that extends east of a high-level platform on the south side of the tracks, a platform that crosses that street. It's currently blocked off, but the platform is low enough to let cars drive across it. I got another pre-construction street-view snippet, showing a high-level platform that was already in place.

The new track pavement has "MUNI TAXI ONLY" on it at several places.

Almost like trying to build an isolated-median line in a city street.

That was the western end of Part A, the part already built. So I get into Part B, the part under construction.

Here also is an old high plattform, on the north side, with a planned extended platform that will block off 36th Ave. Between 36th and 37th Aves. is Sunset Boulevard. Google Maps shows what looks like early construction there.

At 32nd Ave. we can see the pre-construction appearance of the new low platforms: marked-out areas on the street. There is another one to be built at 30th Ave and one at 26th Ave. At that latter one, I came across a street view that shows no markings.

Continuing further, at 22th Ave. is some island platforms to be extended, though they will not block any streets. Then some marked-out platforms at 19th Ave. and a platform on the south side of the street at 17th Ave.

Then south into 15th Ave., and a a "transit bulb" on the east side of the street, the north side of the route. Seems like the missing platform. Then east into Ulloa St. A stop will be moved one block westward from Forest Ave. to 14th Ave.

That seems to end the scope of the work, though as I did street view beyond that, the sky abruptly changed from overcast to clear with thin clouds. About two or three streets more, and then the West Portal station.

I looked at the other Muni Metro lines, and none of the others had any similar construction. From downtown SF, the N Judah line goes in some narrow streets before going into its eponymous street. The line has street platforms on each side for the rest of its length.

The J Church and the K Ingleside also have some street platforms, but the M Ocean View seem to have much less of them. However, the M Ocean View line has some private right of way a little south of West Portal and a center-platform station at Stonestown Mall.

As a comparison, I looked at some recently-built lines in SF: the Embarcadero Line from Market St. to the Caltrain station (1998), and the Third Street line southward from there (2007) and the Central Subway line northward from there (2022-2023).

The Embarcadero Line runs in a reserved median, with cobblestone paving on much of its length, and the Third Street Line in a less-obvious reserved median: it has lots of 1-ft * 6-in white miniature speed bumps in its right of way. I found no such bumps in the above-ground part of the Central Subway, though its tunnel portal has cobblestone paving.

The Embarcadero Line has center platforms, and the Third Street Line has some center and some staggered side platforms, something I've seen in other light-rail stations. The Central Subway's above-ground station at 4th and Brannan Sts. has a center platform. The L Taraval new platforms are mostly staggered side platforms, for instance, and that's also true of most of the other Muni Metro side platforms in streets.

I discovered that Google Street View has the month and year on it.

The western end of Taraval St. is dated Mar 2022, while 40th Ave. and some other streets are dated Feb 2015. At Taraval St. and 37th Ave. is a bit dated Jan 2023, then further east on Taraval St. Apr 2019 and May 2022, and east of 36th Ave. Jan 2023. The rest of the L Taraval route is a mixture of those dates.

The thing at 37th is most likely for emergency vehicles with bollards that are designed to be knocked over with sufficient force in case an emergency vehicle need to drive through. the pavement on either side of Taraval shows that for normal vehicles, you are required to turn right into the street and through driving is not possible.

Looking at the section that hasn't been converted yet, it looks like this project is basically taking what was painted on the pavement with island and hatch marks and turning it into physical barriers and platforms. You don't see this anywhere else because none of the other lines were limited with such narrow right of ways.

L Taraval has a loop terminal using Vicente, 47th Ave., Wawona and 46th, a block north of the Zoo. I don't recall the stub west on Taraval from my 1976 visit, you'd have to ask a local or check a reference book to know how long it's existed. I expect it's a way to short turn one car that's following another too closely. L Taraval has a short-turn wye at 35th Ave, N Judah at 30th.

Both Sunset Blvd. and 19th Ave (CA 1) are high-density north/south bus routes. There are a couple of other "crosstown" (north/south) bus lines in the Sunset too.

I believe the trackage on Taraval west of 47th is the original terminus and the loop down to Wawona was added later. I think the nonprofit society Market Street Railway (full disclosure: I'm a member) is trying to preserve some of that trackage for historical reasons -- something to do with the design of the rail at that location.