K Ingleside
| Company type | Public transit service |
|---|---|
| Industry | Public transportation |
| Founded | February 3, 1918 |
| Headquarters | San Francisco , United States |
Area served | San Francisco, California |
| Products | Light rail transit service |
| Website | www |
The K Ingleside operates as a light rail route within San Francisco's Muni Metro network, mainly serving the neighborhoods of West Portal and Ingleside. It began operation on February 3, 1918, marking the first transit line to run through the Twin Peaks Tunnel.
Route description
The K Ingleside terminates at its outer end at Balboa Park station, where it shares platforms and a terminal loop with the J Church line. From there, it travels along Ocean Avenue in a dedicated median until reaching Ocean Avenue/CCSF Pedestrian Bridge station, then continues in mixed traffic to Junipero Serra and Ocean station. Stations at street level generally have boarding islands positioned between the tracks and adjacent traffic lanes. The line briefly returns to a reserved median on Junipero Serra Boulevard before merging with the M Ocean View line at St. Francis Circle station. Both lines then proceed in mixed traffic to a junction near West Portal station with the L Taraval line. The K Ingleside then continues through the Twin Peaks Tunnel and the Market Street subway, concluding at its inner terminal, Embarcadero station.
Operation
Service for the K Ingleside begins at 5 a.m. on weekdays, 6 a.m. on Saturdays, and 8 a.m. on Sundays, running until approximately 12:30 a.m. During weekday daytime hours, trains arrive every 10 minutes, while weekend intervals extend to 12 minutes.
Overnight coverage is provided by Owl bus routes: one connecting West Portal and Embarcadero, another between Balboa Park and West Portal, along with a limited service route operating during late night and early morning hours.
Prior to the COVID-19 pandemic, weekend operations started with the K Ingleside Bus running from 5 a.m. until rail service commenced. This bus route followed the rail corridor but utilized surface streets where the rail had exclusive rights-of-way.
Market Street Railway
On December 4, 1895, the Market Street Railway inaugurated a branch of its Mission Street line extending along Ocean Avenue to Victoria Street. Constructed in only six days to serve Ingleside Racetrack, this line was soon extended further to Ingleside House near Junipero Serra Boulevard. After the transit system suffered damage from the 1906 earthquake, United Railroads (URR), which succeeded Market Street Railway, discontinued many cable car routes and expanded electric streetcar services. Service resumed on Ocean Avenue (route 12) on May 6, 1906, eventually extending to Ocean Beach via Junipero Serra and Sloat Boulevards.
Municipal Railway
The San Francisco Municipal Railway (Muni) introduced its K line concurrently with the opening of the Twin Peaks Tunnel on February 3, 1918. The initial routing ran from St. Francis Circle station along West Portal Avenue through the tunnel and Market Street to Van Ness Avenue, connecting with the J Church line at Church Street and continuing along Van Ness Avenue to Pine Street. On June 1, 1918, both J and K lines were rerouted off Van Ness Avenue and extended along Market Street to a loop at the Ferry Building.
Expansion into Ingleside was initially constrained by existing United Railroads of San Francisco (URR) streetcar operations on Ocean Avenue. However, on November 25, 1918, Muni and URR reached the "Parkside Agreements," allowing Muni streetcars access to URR tracks on Ocean Avenue up to Harold Avenue and on Taraval Street, in exchange for payments and shared maintenance responsibilities. By February 21, 1919, the K Ingleside extended south along Junipero Serra Boulevard and east on Ocean Avenue as far as Miramar Avenue, then further eastward to Brighton Avenue and southward terminating at Grafton Avenue by May 18.
Starting April 13, 1919, alternate inbound cars on Sundays and holidays continued onto the L Taraval line instead of heading downtown; this practice ended in October 1923 when L Taraval service began running downtown full-time. From January 15, 1939, alternate inbound cars served the East Bay Terminal, with all cars doing so by January 1, 1941. Following Muni's acquisition of Market Street Railway (formerly URR) in 1944, route 12 service was discontinued on Ocean Avenue in April 1945, leaving only the K Ingleside operating there. On April 21 that year, every other outbound K car was extended along Ocean Avenue and Onondaga Street to Mission Street for direct connection with route .
On January 21, 1951, evening and holiday streetcar service on K and L lines was replaced by a crosstown bus route. Rail service resumed May 18, 1952; trackage beyond Brighton Avenue was abandoned and replaced by the Phelan Loop near City College. Service past Phelan Loop towards Mission ended October 10, 1952; however, tracks toward San Jose Avenue remained for non-revenue moves.
Due to construction of the Market Street subway, starting December 2, 1972 service was rerouted via Duboce Avenue, Church Street, and 17th Street. On April 23, 1979, the line was extended to reach Balboa Park BART Station. Initially, supplemental weekday trips operated using new Boeing Light Rail Vehicles (LRVs) between West Portal and Balboa Park while most K-line runs continued with PCC streetcars from downtown to Phelan Loop. The LRV shuttle ended in February 1980; PCC service briefly extended to Balboa Park before weekday operations fully transitioned to LRVs with a temporary K-L crosstown route. By December 17 of that year, K line trains ran through-service from Embarcadero Station to Balboa Park using LRVs during weekdays; weekend PCC operations persisted until September 1982 when full Muni Metro service commenced.
Between February 2001 and June 7, 2003, K Ingleside service was truncated at St. Francis Circle with buses replacing trains along Ocean Avenue during major reconstruction work that upgraded tracks and overhead power systems while adding accessible platforms at Ocean and Lee.
After June 30, 2007 adjustments linked K Ingleside with the T Third Street line inside the Market Street subway tunnel while maintaining separate route designations. This formed an inverted horseshoe-shaped corridor from Balboa Park extending through Bayshore to Sunnydale. At West Portal Station, inbound K trains change signage to T line heading downtown; conversely at Embarcadero Station, T trains switch their signs to indicate K line service. Trains display their ultimate destinations rather than intermediate stops.
Subsequent modifications
Between June 25 and August 24, 2018, service along the line was adjusted due to the closure of the Twin Peaks Tunnel. The underground segment west of Castro station was shut down, and the surface K line was routed continuously with the J Church line.
Following the tunnel's reopening on August 25, 2018, Muni introduced permanent two-car trains on the K/T line. Because of limited platform lengths, the rear car remained inaccessible on the Ocean Avenue portion. Passengers were required to move to the front car at Junipero Serra and Ocean station, with inbound K trains only opening their rear car beyond this point.
On March 30, 2020, Muni Metro switched to bus operations amid the COVID-19 pandemic. Rail service recommenced on August 22, 2020, accompanied by route adjustments designed to enhance subway reliability: K Ingleside and L Taraval were interlined between Taraval and Sunset and Balboa Park station, bypassing the subway; meanwhile, T Third Street was paired with M Ocean View instead of K Ingleside. The transfer required at West Portal attracted criticism from disability rights groups. Due to overhead wire splice complications and COVID-19 quarantine measures, K Ingleside light rail reverted to bus substitution on August 25, 2020.
Light rail service restarted on May 15, 2021, once again through-routed with T Third Street. On January 7, 2023, T Third Street was redirected into the Central Subway, ending its interlining with K Ingleside, which resumed terminating at Embarcadero. The two lines briefly reconnected from February 26 to March 14, 2025 during a Central Subway closure.
In 2023, SFMTA launched the K Ingleside Rapid Project aimed at boosting capacity and decreasing travel times along Ocean Avenue. Principal improvements include lengthening platforms at four stops to accommodate two-car trains, removing one stop entirely, and establishing transit-only lanes between Junipero Serra Boulevard and Lee Avenue. These measures received approval from the SFMTA board on March 5, 2024. The "quick-build" phase began in August 2024 with platform reconstruction; concurrently, the stop at Ocean and Westgate / Ocean and Cerritos was closed on September 28, 2024. At that time, two-car trains started fully opening both cars for passengers up to Ocean Avenue/CCSF Pedestrian Bridge inbound. Full construction of the project is scheduled for 2027–2029.
Upcoming plans
In 2016, SFMTA proposed extending the K Ingleside light rail line from Balboa Park to Bayshore station, with estimated costs ranging from $260 million to $610 million and a projected completion in the 2030s. Another concept involved routing the K line through a new M Ocean View subway extending westward to St. Francis Circle, featuring a portal located in the median of Junipero Serra Boulevard.
Station listing
The K Ingleside line operates with concrete boarding islands adjacent to tracks; several stops also provide raised platforms for accessibility purposes.
External links
- SFMTA – K Ingleside-T Third Street