Andre Chevalier likes to stream music on his phone when he's commuting on San Francisco's Muni Metro trains.

But every time his N-Judah goes underground, he loses his signal to the streaming service Pandora - and every other online site, e-mail provider and cell phone signal.

It's the 21st century equivalent of being stuck on a desert island. No way to tell friends, co-workers or dates if you're running on Muni Standard Time, i.e., late. And no tunes to block out the crazy guy chattering across the aisle.

"I'm just left here on my own with my own thoughts and the people around me," said Chevalier, 26, who lives downtown and works as bicycle mechanic in the Sunset.

Muni has zero underground cell phone coverage, and there is no firm timeline for installing antennas in the downtown subway or any other tunnel, said Paul Rose, a spokesman for the transit agency. More than 350,000 people ride the subway each day.

"While this is a resource we would like to provide, we have significant state-of-good-repair needs, and our main priority is to invest in our service," Rose told Chronicle Watch.

Muni officials have asked cell service companies if they would install the equipment free of charge, but have not gotten a lot of interest, Rose said.

"We have reached out to the cell phone providers in the past and haven't gotten a commitment to fund this fully," Rose said. "That's been the issue up until now."

BART has had complete cell service coverage since 2010, and most other major underground transit systems in the United States have at least some cellular data coverage.

The lack of cell service means riders are stranded in more ways than one when Muni stalls - as it often does - underground. They can't tell friends they're running late, or find out why the train is stopped.

Tom Nolan, chairman of the board that oversees Muni, said he was riding a train last week when it stalled in a tunnel near the intersection of Church Street and Duboce Avenue.

"The train just stopped and this totally inaudible announcement came on," he said. "We sat there for 10 minutes and no one knew what was going on.

"It is kind of embarrassing at this point that we aren't better than we are," Nolan said. "We hear from customers all the time who let us know they want to know what is going on" with cell service.

BART first formed a plan to start developing cell service in its downtown subway in 2001, said Alicia Trost, a BART spokeswoman. By 2010, every tunnel in the agency's system had coverage.

BART paid no money to install the wireless antennas and charged carriers a licensing fee, making $742,000 in the 2010 fiscal year, the most recent for which numbers are available.

Muni Metro, which has fewer riders than BART and shorter tunnels, has had less success.

"We are going to continue to work with cell phone providers and consider funding options, but the main priority is to improve service," Rose said.

Not everyone hopes Muni works things out. Some riders say they see the Muni dead zones as a break from the need to always be connected.

"You're underground," said Matthew Marchand, who rides the T-Third Street. "What did you expect?"

Chronicle Watch


What's not working

Issue: Muni streetcar tunnels aren't outfitted with cell phone antennas, leaving the tens of thousands of commuters who ride the downtown subway stuck in a dead zone.

What's been done: Muni has talked with cell service providers, but has not gotten much interest. It says improving transit service is a higher priority.

