With the last-minute addition of suggestions from the Federal Communications Commission, the BART board quietly ended the long, noisy, often angry controversy over its August shutoff of subterranean cell phone service.

The board, on a 7-0 vote, adopted a policy outlining when and how the transit agency may shut down the antennas that provide cell phone service to its underground station. There was such little discussion that directors Lynette Sweet and Joel Keller, who were out of the room to discuss another matter, did not return in time to cast their vote.

BART became the center of a fierce debate over First Amendment rights in the modern era when it shut down the system that provides cell phone and wireless access in its underground San Francisco stations on Aug. 11 to thwart protesters' plans to stop service by chaining themselves to trains. While the tactic prevented that from happening, it prompted outrage from civil libertarians, protesters and other activists, and led to international publicity, hacker attacks on BART-related websites and months of protests that shut downtown San Francisco stations on multiple occasions. The controversy also persuaded BART officials to adopt a policy.

"If we were faced with the exact same situation, we would not shut off cell phone service," said Bob Franklin, board president. "We would arrest people."

The policy limits temporary shutdowns to "the most extraordinary circumstances" posing danger to public safety, destruction of BART property or "substantial disruption" of service. It includes two statements suggested by the FCC late Wednesday in response to BART requests for feedback.

The FCC, in a phone call, asked BART's staff to add wording that "recognizes that any interruption of cell phone service poses serious risks to public safety" as well as a section requiring "a determination that the public safety benefits outweigh the public safety risks of an interruption."

While some directors viewed the FCC input as support for the BART policy, Franklin said it was merely a suggestion to include the two statements, which BART counsel Matthew Burrows did, verbatim.

"It's not an endorsement," Franklin said.

Despite the lengthy series of protests sparked by the cell phone shutdown, only one person showed up to speak against the proposal, and he said he had not participated in the demonstrations.

Bryce Nesbitt of Berkeley said he agreed with allowing BART to switch off cell phone service to protect public safety and property but not to prevent service disruptions. That provision, he said, could allow cell service to be curtailed to prevent a demonstration, which would surely fuel more public outrage.

"It just isn't worth it," he said.

The policy permits the transit district to turn off cell phone service "only when it determines that there is strong evidence of imminent unlawful activity" threatening safety, property or service. It requires the agency to limit the use of the tactic to areas and time periods where it is needed, and requires the decision to be made by the general manager or a specific designated person and process.

It also offers examples of the kind of extraordinary circumstances that would warrant the shutoff of cell phone access - evidence of plans to use cell phones to detonate explosives, endanger BART passengers or employees or facilitate plans to destroy district property or "substantially disrupt" transit service.