Speaking from an energizer station set up on the north side of the Golden Gate Bridge, Joe Fragola, a spokesman for one of the event's major sponsors, Kaiser Permanente, said everything seems to be kicking off well so far.
"It's early, but we've had a few bikers pass through already," Fragola said at around 5:30 a.m. Last year, 4,000 people in Marin County participated in Bike to Work Day, according to the Marin County Bicycle Coalition.
Fragola hinted that temperatures so far were lower than years past, though the weather is not expected to affect participant numbers.
"It's a little cool out," he said. "Two years ago it was a Spare the Air day."
Communities around the Bay Area are participating in the annual event.