Crews will be working around the clock in San Francisco's South of Market neighborhood for eight days beginning Friday to seamlessly connect the T-Third line to the new underground Central Subway, according to the San Francisco Municipal Transportation Agency.
John Funghi, the SFMTA's Central Subway program director, stood at the corner of Fourth and Brannan streets Thursday by the Caltrain station where he explained, over the roar of passing traffic, how the intersection will be altered to connect existing Muni infrastructure with the Central Subway.
Starting Friday at 10 p.m., motorists will be rerouted around the intersection and surrounding streets while crews work around the clock to lay two and a half blocks of extension rails from the T-Third line to connect it with the completed Central Subway tunnel at Fourth and Bryant streets.
Funghi said commuters should expect delays and prepare for significant detours. Traffic will be rerouted until the evening of Nov. 14, but motorists will still have access to the Interstate Highway 280 on and off ramps.
Bus shuttles between the Sunnydale neighborhood and Embarcadero station will replace the T-Third line's light rail vehicles during the weeklong closure.
Riders traveling between Embarcadero Station and Fourth and King streets will need to transfer to the N-Judah or the T bus shuttle at Embarcadero station.
Traffic closures will be in place on eastbound King Street between Fifth and Third streets, southbound Fourth Street between Berry and King streets, northbound Fourth Street between Channel and King streets, as well as the southern portion of the Fourth and King streets intersection.
Additionally, the N-Owl will have a temporary stop on Townsend Street between Fourth and Fifth streets, while the 91-Owl will have a temporary stop at Third and Berry streets.
Caltrain customers heading downtown are encouraged to take the 10, 30, 45, 81X or 82X Muni bus lines, according to the SFMTA.
The 81X and 82X, which operate during peak hours, will operate from a temporary stop on Townsend Street between Third and Fourth streets.
This detour and closure marks the second phase of the work that began on Labor Day weekend and coincides with massive utility upgrades at the intersection at Fourth and Brannan streets to prepare for a new transit station there.
Some of the utilities that are being replaced at the intersection are over 100 years old, Funghi said.
Trains won't actually proceed into the new tunnel until about 2018 and won't be ready to serve the public until about 2019, at which point transit riders will be able to go to a new Union Square station or transfer below ground to the Powell Street station.
Once the extended T-Third line is up and running, the SFMTA estimates that roughly 65,000 riders will travel on it per day, which could make it one of the most popular transit lines in the country.
The SFMTA estimates roughly 38,000 transfers will occur from the T-Third line when it is completed.
"We're changing people's commute patterns," Funghi said,
explaining that this coming week will be the biggest push yet in the Central Subway project and cause the largest impact to the public caused by the project to date.
When the crews complete their work on Nov. 14, pedestrians and motorists will be able to see new switch points on surface streets with tracks going in four different directions, Funghi said.
Additionally, from 5 a.m. Saturday until Nov. 16, crews will be working on the Sunset Tunnel construction project, requiring buses to replace N-Judah rail service between Ocean Beach and the intersection of Church and Duboce streets, according to the SFMTA.