T Third Street

The T Third Street is a Muni Metro line in San Francisco, California. It is the first new light rail line in San Francisco in more than half a century and the first fully accessible line in the system.

T Third Street
Northbound T-Third train passing Mission Rock station, April 2018.
Overview
Owner	San Francisco Municipal Transportation Agency
Locale	San Francisco, California
Termini	West Portal Sunnydale
Stations	30
Service
Type	Light rail
System	Muni Metro
Operator(s)	San Francisco Municipal Railway
Daily ridership	40,600 (2019; combined with K Ingleside)[1]
History
Opened	January 13, 2007 (2007-01-13) (limited service) April 7, 2007 (2007-04-07) (full service)[2]
Technical
Track gauge	4 ft 8 1⁄2 in (1,435 mm) (standard gauge)
Electrification	Overhead lines, 600 V DC
Route diagram Legend Chinatown Union Square/​Market Street Powell Yerba Buena/​Moscone I-80Module:Jct warning: "rdt" parameter is deprecated Central Subway 4th and Brannan Caltrain 4th and King 4th Street Bridge Mission Rock UCSF/Chase Center Mariposa Mission Bay Loop 20th Street 23rd Street   Muni Metro East Yard   Marin Street Levon Hagop Nishkian Bridge over Islais Creek Evans Hudson/Innes Kirkwood/La Salle Oakdale/Palou Revere/Shafter Williams Armstrong wye Carroll Gilman/Paul Le Conte US 101Module:Jct warning: "rdt" parameter is deprecated Caltrain Arleta Sunnydale Bayshore proposed Caltrain to San Jose This diagram: view talk edit

Route description

The destination sign of an inbound Muni Metro K train changed from K Ingleside to T Third Street at West Portal Station.

Testing on the line took place in summer 2006,^[3] with limited service starting on January 13, 2007, and full service beginning on April 7, 2007.^[4] It runs along the newly constructed light-rail tracks on Third Street and Bayshore Boulevard in the Visitacion Valley, Bayview/Hunters Point, Dogpatch, and Mission Bay neighborhoods, connecting to the existing Muni Metro system along the Embarcadero and under Market Street.

In the future, the line may be going to Caltrain's Bayshore Station (to which it was originally planned to run) and, in the other direction, to San Francisco's Washington Square in North Beach through Chinatown Central Subway route.

Operation

The T Third operates seven days a week, beginning at 5 a.m. on weekdays, and 6 a.m. Saturdays and 8 a.m. Sundays, operating until 1 a.m.

History

Following service changes on June 30, 2007, the K Ingleside and the T Third Street lines were combined inside the Market Street subway tunnel.^[5] Though keeping their line designations, resulting in an upside-down, horseshoe-shaped route from Balboa Park to Bayshore and Sunnydale. At West Portal Station, inbound K trains heading towards downtown change their signs to the T line; at Embarcadero Station, T trains heading into downtown change signs to the K line.

The underground section of the line was closed west of Castro station from June 25 to August 24, 2018, due to the Twin Peaks Tunnel shutdown.^[6] On August 25, 2018, at the end of the shutdown, Muni began running two-car trains on the K/T line.^[7]

Central Subway

Main article: Central Subway

Central Subway construction at the south portal in December 2017.

Service on the Central Subway was initiated on November 19, 2022, with shuttle trains serving the four new stations.^[8] The T-Third will reroute north of the 4th and King Station starting on January 7, 2023. This change will disconnect the T from the K line, avoiding both King Street and the Market Street subway.^[9]