By now, South Bay BART riders were supposed to be streaming into the new Milpitas and Berryessa stations. Oakland and San Leandro bus passengers were supposed to be zipping past International Boulevard traffic in dedicated bus lanes. And Nimitz Freeway drivers were supposed to be using new express lanes to get a quicker trip on I-880.

But riders and drivers are still waiting and can expect to keep waiting for a while.

AC Transit reportedly has pushed back its plan for opening the bus rapid transit line to late spring.

The express lanes now are planned for this summer — mid- to late August, according to the Metropolitan Transportation Commission.

And after their long-delayed project missed yet another deadline last week, officials from BART and Valley Transportation Authority, which built the extension, still don’t have an estimate for when the gleaming new Milpitas and Berryessa stations finally will open for service.

“I am not going to speculate one way or another,” VTA spokeswoman Bernice Alaniz said this week when asked how long riders can expect to wait for the project. “All I can definitively say is that VTA and BART are working in as expedient and efficient a manner possible to deliver a safe and reliable system.”

Each of those three new projects had at one point been slated for completion by the end of 2019. They are among several big Bay Area transportation projects dogged by delays during the last decade — something experts say the region needs to fix as it looks to tackle even more ambitious projects, including the next phase of the BART extension through downtown San Jose and Caltrain’s push into downtown San Francisco.

The new BART stations originally were supposed to open to the public in 2018, but that schedule has been pushed back several times.

Until last fall VTA officials insisted the project was on track to open by Dec. 28 then acknowledged in November that it wouldn’t make that deadline either.

Since then, no one at BART or VTA has been willing to estimate when the $2.3 billion, 10-mile extension will open. At one point, statements from BART and VTA pointed toward a possible late April or May opening, but that now seems unlikely.

Instead, Alaniz said the agencies now hope to release a schedule sometime next month for the eventual opening.

VTA officials said in December that they planned to finish “base project work” on the extension by the end of January. But Alaniz said that hasn’t happened — crews are still working to fix a software problem that is keeping BART’s trains from stopping at precise spots where the trains’ doors line up with the black tiles on the platforms.

Beyond that fix, VTA crews still need to resolve hundreds of other “discrepancies” with the extension before they can turn it over to BART, which will operate the system.

Whenever that happens, BART still will need some time to conduct its own testing before service to the stations begins. BART officials last year estimated that would take about 12 weeks but have since backed away from that time frame.

“We are continuing to work closely with VTA as their contractors execute their work and testing,” BART spokeswoman Alicia Trost said.

While that work continues, South Bay BART riders have gotten the short end of a slate of changes VTA rolled out in late December, which bolstered service along the agency’s more popular bus routes while reducing the frequency of buses on others, and eliminating some entirely. Those changes have included less-frequent service for the express VTA bus line between the Warm Springs BART station and downtown San Jose, plus a slower trip after the agency gave the route an extra stop in Milpitas.

Delays for rapid buses as well

Anyone who has traveled along International Boulevard or parts of downtown Oakland lately has been seeing the signs of progress on the long-awaited bus rapid transit line along the corridor, which includes dozens of shiny new bus shelters.

Let there be light! Pictured here is one of our 21 center-median stations at 73rd Avenue. The newly-installed lighting will help improve safety for riders and pedestrians at #BRT’s 46 platforms between #Oakland and #SanLeandro. #ACTransit #EastBayBRT coming spring 2020 pic.twitter.com/HUMSLXaPzf — Rideact BRT (@rideactBRT) February 4, 2020

With dedicated lanes to free coaches from automobile traffic — and bus-mounted cameras to ticket drivers who sneak into the lanes — transit advocates hope the AC Transit system becomes a model for similar rapid bus lines throughout the Bay Area.

AC Transit officials said in November that the project was behind schedule, pushing their planned opening from December to March. They said crews found unmarked utilities along the route, as well as a sinkhole along one block of International Boulevard, all of which slowed construction.

Now AC Transit estimates the line will open in May, according to the transportation news site Streetsblog, with the caveat that wet weather could create more delays. An AC Transit spokesman did not immediately respond to a request for comment on the report Thursday.

The 9.5-mile line eventually will run from the San Leandro BART station to Uptown Oakland, primarily along International Boulevard. It has faced resistance that goes beyond the usual complaints for drivers about dedicating lanes to public transportation, though.

As the Bay Area’s housing crisis drives up rents across Oakland, many worry the new transit line could worsen gentrification in the neighborhoods it will run through, pushing more longtime residents out. Business owners have also complained that the project eliminates some parking spaces along International Boulevard and are weary from years of construction which one blamed for the closure of a 70-year-old furniture store as the project dragged on.

Amid the delays, AC Transit is offering a silver lining for those waiting to ride the new line: Once it opens, the agency won’t charge for rides along the bus rapid transit route for its first 90 days.