BART’s long-awaited Warm Springs extension to open March 25

Photo: Courtesy Metropolitan Transportation Commission, Metropolitan Transportation Commission/Noah Berger The new Warms Springs BART Station in southern Fremont will open...

BART’s long-delayed extension to Warm Springs will open in two weeks, moving the Bay Area’s regional transit backbone closer to serving San Jose and bringing thousands more parking spaces.

The extension reaches from the Fremont station, currently the end of the line, 5.4 miles south to the new Warm Springs/South Fremont station near the Tesla auto plant in Fremont. Trains will start carrying passengers to and from the station on March 25.

“This will bring BART service to the residents of fast-growing south Fremont,” said Tom Blalock, a veteran BART director from Fremont, in a statement. “They’ll have a reliable, environmentally responsible alternative to driving on the nightmarish Nimitz Freeway.”

The extension is the first step toward taking BART into its fifth county, Santa Clara — and it could happen sooner than initially anticipated. A two-station extension to the Berryessa neighborhood of San Jose, being built and paid for by the Santa Clara Valley Transportation Authority, is expected to open by the end of the year, several months ahead of schedule.

That was not the case for the Warm Springs extension. BART had planned to open it in 2014. Construction began in 2009 with work crews excavating a mile-long tunnel beneath Fremont’s Central Park and Lake Elizabeth, but various problems pushed the opening back to 2015. It was delayed again into 2016, when it was expected to debut sometime last summer.

But issues with getting the extension to reliably communicate with BART’s automatic train control system pushed the opening back into this year. BART spokesman Jim Allison said Friday that the fixes involved writing new software for the computer that runs trains.

Meanwhile, the gleaming new glass and white-painted-steel station sat finished but empty, disconnected from the rest of the BART system. Nevertheless, it was staffed with five station agents, two janitors and a train controller because of a quirk in the way BART schedules workers.

But now, test trains are running as expected, and the California Public Utilities Commission is expected to grant a mandatory certification Sunday night that will allow BART to start service, Allison said.

Image 1 of / 3 Caption Close BART’s long-awaited Warm Springs extension to open March 25 1 / 3 Back to Gallery

Despite the delays, the extension is expected to be completed on or under its $890 million budget, he said.

BART’s newest station features 2,082 parking spots, including 42 electric-vehicle charging stations and bus stops close to the station entrance. Valley Transportation Authority buses will not serve Warm Springs/South Fremont station, said Stacey Ross Hendler, a VTA spokeswoman. However, buses from Fremont to downtown San Jose will continue, she said, until the Berryessa extension opens late this year.

“Then people will be able to take BART to San Jose,” she said.

A public opening ceremony and station preview will be held March 24 from 10 a.m. to noon. The station is located at 45193 Warm Springs Blvd. Trains will not run between Fremont and Warm Springs/South Fremont until March 25 but free shuttle bus service to and from those locations will be available and the parking lots will be open.

BART last opened a station on its main lines in 2011 when it debuted its first infill station at West Dublin/Pleasanton. In 2014, BART opened its Oakland Airport Connector, an automated line with trains pulled by cables between the Coliseum station and Oakland International Airport.

Warm Springs/South Fremont is the first new BART station to be built on the Richmond-Fremont line since service started in 1972. It will become the rail system’s 46th station and for a few months will be its southernmost.

VTA’s 10-mile extension to Berryessa in east San Jose will also stop in Milpitas, where there’s a connection to VTA’s light-rail system. When the project is completed, possibly as soon as the fall, it will be turned over to BART and become part of the regional system.

Santa Clara County officials plan next to extend BART six miles farther to downtown San Jose and Santa Clara — a project that’s being designed but is not yet fully funded. It is tentatively scheduled to start service in 2025.

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan