BART riders face new shutdown near SFO amid ongoing delays

Bay Area travelers headed to and from San Francisco International Airport faced another difficult commute on Thursday morning as BART halted service between San Francisco International Airport and Colma because of a train control equipment problem, adding to a string of recent disruptions on the busy airport corridor.

Morning shutdown cuts BART link to SFO

According to regional wire reports, BART service stopped between San Francisco International Airport and Colma stations early on Thursday, September 10, because of a train control equipment issue near South San Francisco. The shutdown affected both northbound and southbound service on the Yellow and Red lines, which normally provide the primary rail connection from downtown San Francisco and the East Bay to the airport.

Coverage from local outlets indicates that the interruption triggered major delays across the system, with riders on airport trains told to expect significant additional travel time or to seek other transit options. The disruption came during the morning travel period when airport workers and early flight passengers typically rely on the SFO extension for predictable access to the terminals.

Publicly available alerts from the transit agency show that the problem centered on train control equipment, a critical part of the system that regulates train movements and spacing. When those components fail or require emergency repairs, service often must be reduced or suspended altogether to maintain safe operations.

As of late morning, advisory pages and partner news coverage described the situation as a major delay, with no immediate estimate on when full service between Colma and SFO would resume. Riders were encouraged to check real time updates before starting their trips.

New closure follows night of fires and equipment failures

The airport shutdown came less than two days after a series of separate incidents involving BART infrastructure near Daly City and West Oakland, which also had ripple effects on service to SFO and Millbrae. A BART news release on Wednesday described a fire at a power substation near Daly City on Tuesday night, September 8, which temporarily disrupted service and damaged train control equipment in the area.

Even after trains were running again to all stations, the agency reported that speeds between Daly City and Colma had to be reduced while additional repairs were planned, leading to delays of up to 20 minutes on some trains. That same morning, regional television coverage highlighted further slowdowns linked to an unrelated trackside issue near West Oakland and a medical emergency aboard an SFO bound train.

Separate coverage from local broadcasters and national news aggregators on Wednesday described “major delays” across the San Francisco line, including trains in the SFO, Millbrae, and Daly City directions, as these multiple problems compounded. Social media posts from riders and media outlets captured images of crowded platforms and extended waits as commuters tried to reach the airport and Peninsula destinations.

For many regular travelers, Thursday’s closure between SFO and Colma reinforced the sense of a difficult week on the system, particularly for those who depend on BART’s airport extension for work shifts, early departures, and late night arrivals.

Ongoing modernization work adds pressure on SFO corridor

Even before this week’s equipment failures, BART riders between Millbrae and SFO had been asked to plan for recurring delays tied to modernization projects. BART’s published advisories describe long running work to install a new Communications Based Train Control system on the San Mateo County segment, including the stretch that links SFO, Millbrae, San Bruno, South San Francisco, Colma, and Daly City.

A BART project notice issued late last year outlined evening construction windows that can create 30 minute delays starting at 9 p.m. on some Sunday through Thursday nights between Millbrae and SFO, as well as reduced speeds and occasional single tracking in the area. The advisory notes that this section has been prioritized as one of the first to receive the upgraded train control technology, which is intended to improve reliability and capacity once fully in place.

Presentations linked from the agency’s budget and capital program materials also identify the corridor near Millbrae and SFO as a focus of the multi year modernization plan. That planning documentation highlights repeated work windows near the airport to support the first phases of the new signal system, a process expected to continue into the late 2020s.

As a result, travelers on the SFO extension are contending with both planned slow orders for capital work and unplanned outages like this week’s equipment failure. For airport bound passengers, the distinction often matters less than the practical outcome of longer travel times and less predictable connections.

Airport and regional travelers face limited alternatives

When BART service is cut between SFO and Colma, riders have a mix of alternate options, but many involve trade offs in cost, time, or convenience. Caltrain’s service plan shows frequent trains to and from Millbrae throughout the day, and the rail operator describes a coordinated pattern in which BART typically runs a shuttle between Millbrae and SFO every 15 minutes after 9 p.m. during normal operations. During an outage, however, that shuttle pattern can be suspended or altered, and riders may need to rely on buses or road based services instead.

SamTrans, ride hailing providers, shared shuttles, and private airport vans all serve SFO, but can be subject to highway congestion and higher fares, particularly at peak times. For travelers starting in San Francisco or the East Bay without easy access to Caltrain, reaching Millbrae or South San Francisco by bus or rideshare may add substantial time compared with a single BART ride to the terminal station beneath the airport.

Regional coverage of this and previous disruptions has noted that workers with early morning or late night shifts at SFO are especially exposed when the rail link is interrupted, since bus frequencies and carpool options are often lower at those hours. Visitor trips can also be affected, particularly for travelers unfamiliar with the network who may have chosen lodging or planned itineraries based on a direct rail ride from downtown San Francisco to the airport.

These repeated disruptions are likely to factor into travel decisions heading into the fall, as more visitors return to the Bay Area and local employers refine hybrid schedules that already depend on reliable early and late service to the Peninsula.

What BART riders should watch in the coming days

For now, the key variables for airport bound riders are when full service will resume between Colma and SFO and whether reduced speeds or further closures will continue along the Daly City corridor. The transit agency’s advisories page and trip planner remain the primary reference points for real time conditions, and regional news outlets have been quick to amplify updates when major delays or shutdowns occur.

Travelers planning trips over the next several days may want to build extra time into their airport journeys, particularly during early morning and late evening periods when alternatives are more limited. It can also be useful to check Caltrain schedules to and from Millbrae, as well as SamTrans routes serving SFO, in case a backup option becomes necessary while BART trains are slowed or stopped in the area.

In the longer term, BART’s published capital plans and project updates suggest that work on the airport corridor will remain a focus as the new train control system comes online. The modernization effort is intended to reduce the frequency of the kinds of equipment failures that have troubled riders this week, but the transition period is likely to involve further planned disruptions even after the latest emergency repairs are complete.

For travelers heading to or from SFO, staying informed and allowing extra time may remain part of the routine whenever their journey depends on BART’s busy airport extension.