Transbay Tube Retrofit


The Transbay Tube is BART’s most critical asset. Although the tube is structurally sound, in a very large and very rare earthquake event, the outer shell and concrete liner are predicted to crack, causing leakage.

To minimize leakage in the event of a 1,000 year earthquake, BART has awarded a 313-million dollar contract (to Shimmick Construction and California Engineering Contractors Inc.) for a massive project that will retrofit the Transbay Tube.

To give crews the time needed to get the work done, BART plans to open the entire system one hour later on weekdays for the project’s duration. This means changing from a 4:00 a.m. to a 5:00 a.m. start of service for a period of up to 3.5 years. The 5 am opening is temporary. There have been no discussions nor actions taken to make it permanent. A careful evaluation of both our riders needs and maintenance requirements would be conducted before any such decision would be made.

This extra hour each night will extend the available work window by at least 20% and save the project a minimum of $15 million.

The specific date for when the service change will take effect is February 11, 2019. View the original March 22, 2018 presentation given to the Board. Please note, details have been updated since this presentation.

The Board received an update on the proposed mitigation options at the July 12, 2018 meeting.  View the July 2018 board presentation.

A finalized alternative bus service plan complete with parking payment options was presented to the Board on October 11, 2018. Preview the board presentation. 

What’s Being Done

This project will help ensure any earthquake-caused leaking is slowed to a point that will give people time to evacuate, with a second priority of keeping the leakage low enough that the tube can eventually be repaired.

The work itself involves installing an inner steel lining to the 3.6 mile-long tube, which is made of a reinforced concrete liner with an outer steel shell.

It also involves the construction of a new pumping system that will allow larger quantities of water to be removed more quickly from the tube.

One Hour Goes a Long Way

Adding this one hour a will shorten the project timeline by 4 months.

It will also give our crews more time for track inspections, preventative maintenance, and Measure RR bond funded rebuilding projects throughout the system such as power cable replacement through San Francisco and rail replacement. The extra wrench time will speed these projects up by at least 25%, provide a minimum12% cost savings and increase the maintenance productivity of our crews by 43-62%.

In September of last year, an independent study by Transportation Resource Associates was presented to BART’s board.

Among its findings, continued maintenance reforms are essential for BART’s future success and proper maintenance requires the agency to plan service adjustments.

The decision to start service later, as opposed to ending it sooner each night is largely based on data showing there are far more riders (between 5,000 and 6,000) during the last hour of our service window than the 2,900 riders we carry in the first hour.

Beyond that, the work will actually begin at 9:30pm each weeknight when we start single tracking until closing as work trains carry equipment into the tube. This means closing an hour earlier would not give us that extra hour of work time.

Any gained time to the project is at the end of the work day which is after 4:00am.

Early Bird Expres Bus Service

We understand this project will impact our riders.

In addition to the later weekday morning start time, BART will be single-tracking trains through the tube each weeknight from 9:30 p.m. until close of service at midnight.  This will allow crews to shuttle in equipment via the closed track. During this time, trains will run every 24 minutes instead of the every 20 minutes they run now.

About 2,900 passengers enter our system in that first hour of service.

Over 2,400 of them begin their trips in the East Bay and 64% of our first hour riders disembark at downtown San Francisco stations.

The Early Bird Express alternative bus service plan will establish 14 new bus lines to run between 3:50 am and 5:30 am in both directions between stops. There will be 7 transbay routes, 5 East Bay routes and 2 San Francisco/Peninsula routes. The bus network will have 13 points of origin, including 12 BART stations and the Salesforce Transit Center in San Francisco. It will serve a total of 20 BART Stations, including 6 stations in San Francisco. Bus trips leaving from East Bay BART stations will arrive at the Salesforce Transit Center at 5 am, 5:15 am and 5:30 am. (The first trains currently arrive from the East Bay between 4:48 am and 5 am). We are partnering with 8 Bay Area bus agencies to operate this network and all fares will be the same as or less than the equivalent trip on BART.

Download the Early Bird Express fact sheet:

Spanish (En Español):

Chinese (在中文):

new 5am map

BART conducted extensive outreach during the Spring of 2018 which included surveys, in-station outreach, multilingual media ads, community presentations, and meetings with airport employees, hospitality and service workers, business owners and unions.

A summary of the mitigation options and survey results were presented at the July 12, 2018 board meeting. The information has been used to decide what level of alternative bus service to provide during the 4am hour.

Once the schedule change takes effect, end of the line trains will begin around 5 am, Trains will also for the first time begin around 5 am from midline stations (Concord, South Hayward and Daly City) to ramp up the start of service more quickly. All of the trains will start service long with the first train arriving at Embarcadero Station at 5:30 am. 

5am train plan

Parking at BART in the 4am hour

Because BART stations will be closed until 5 am, current parking payment methods will not be available for Early Bird Express riders. We have developed two strategies to allow these riders to continue to pay for parking. The first is the Pay by Smart Phone App. BART plans to launch an official app this fall with the parking payment feature expected to be available for early morning parkers only between 3:45 am and 5:15 am beginning February 2019.

For those who would prefer to pay by cash, day passes will be available for advance purchase by mail or at the customer service centers located at Lake Merritt and at the Embarcadero Clipper Card Office.

Stay informed about Service and Parking Payment Changes. 

If you would like to be notified as details are finalized about these upcoming service changes and EZ Rider parking payment changes, you must opt in to these notifications by clicking here and entering your email address