eBART

For further extension into Contra Costa County and to extend the Pittsburg/Bay Point–SFO/Millbrae line, the DMU system was chosen as an alternative to the existing BART infrastructure because it was claimed to be both less expensive to implement[8] and would more easily allow further extensions.

Initial plans had trains running on the Union Pacific Railroad right-of-way that runs parallel to State Route 4. After Union Pacific declined to grant trackage rights or allow laying of new tracks, the line was merged with a construction project already in the process of widening the adjacent freeway, by laying tracks in its median.[12] Construction of the Railroad Avenue station in Pittsburg had been uncertain as planning and construction progressed but was fully funded by the city to open with the rest of the extension.[13]

Ridership was initially projected at 5600 entrances and exits per weekday[14] (supposing an opening date of 2015).

Transfer platform under construction in 2018

A sales tax increase was approved by Contra Costa voters in 2004 in order to fund the expansion.[15] The expansion was approved by the BART board in April 2009.[16] Costs were set at $463 million (equivalent to $552 million in 2019), compared to an estimated $1.2 billion (equivalent to $1.43 billion in 2019) for full BART buildout.[8] On October 14, 2010, BART issued a press release announcing that the agency had awarded a $26 million (equivalent to $30.5 million in 2019) contract to West Bay Builders, of Novato, "to build the transfer platform and make some of the necessary rail improvements to begin extending the line to a terminus station at Hillcrest Avenue in Antioch."[17]

Construction on the line began in early 2011.[5] Funding for the Pittsburg station was secured in early 2015, and the station opened with the commencement of operations.[13]

Revenue service began on May 26, 2018.[2] The new stations reached 7,441 daily customer entrances and exits within the first three workdays, while ridership and parking levels at the previous terminal, Pittsburg/Bay Point, declined.[14]

While not fully planned or funded as of 2018, expansions of the DMU system could connect eBART service to Oakley, Byron,[12][18] or the Brentwood Transit Center in Brentwood.[19] In 2017, the San Joaquin Regional Rail Commission indicated that eBART could be extended to Tracy, where it would connect with the Altamont Corridor Express and a proposed Valley link line.[20]