Would-be bus passengers also arrived early at El Cerrito del Norte, where the temperature dipped into the 30s, to see how the substitute transit system would work.

Ron Capell, a Vacaville resident who was on his way to work at the Department of Homeland Security, was one of a couple of dozen of people already in line at BART's El Cerrito del Norte Station at 4:10 a.m. -- 25 minutes ahead of the first bus's scheduled departure.

Capell said he arrived early "just to observe the process and make sure I'm able to catch my bus into work."

Lydie Hammack of El Cerrito, who works at a bank in downtown San Francisco, was also in line.

"I'm just worried that if the bus is not on time, I'm going to be late at work," Hammack said. She also expressed concern that the two buses scheduled to take early-morning passengers to the city would be enough to accommodate all the passengers she normally sees on predawn BART trains.

"Now they only have one or two buses? ... I'm worried that there's not going to be enough buses to go," Hammack said.

As the scheduled 4:35 departure time arrived, two Berkeley cyclists expressed some impatience with the commute they saw shaping up.

The bus "should've been sitting here, waiting for us," said Janie Hillyer, who was on her way to her job on a San Francisco Municipal Transportation Agency street-striping crew.

"We left home 40 minutes earlier than we normally would leave," said Patricia Erwin. "And we've been standing here for half an hour and it's less than 40 degrees."

BART personnel told the crowd that the Golden Gate Transit bus that was supposed to take them to the city had gotten delayed at a railroad crossing nearby. Erwin and Hillyer, along with most of the people in the line, wound up giving up on the bus. Many made their way up to the station's train platform, where signs showed the morning's first train was just minutes away.

At 5 minutes to 5, two buses arrived. The remainder of the bus line -- maybe 15 people -- boarded the first and departed.