Advocates for infrastructure that better separates cyclists from drivers took to Valencia Street Thursday evening, forming a human barrier between bike and auto lanes from 16th and 17th streets.

Dozens of cyclists offered high-fives and smiles as they passed through the corridor of roughly 20 yellow-shirted bike lane activists. Most drivers kept silent as they drove by, but a few voiced their dismay.

“Find a different street!” one taxi driver yelled.

“Stop blocking the road!” shouted a cyclist.

Maureen Persico, credited by the activists with originating the idea, stood at the intersection of 16th and Valencia streets, ringing a cowbell and welcoming cyclists to the lane.

“It’s quite a symbolism, we’re using our bodies to protect vulnerable people,” she said.

Persico and others want physically protected bike lanes, either through cement barriers, plastic bollards, or by moving the parking lane toward the center of the road and letting cyclists ride adjacent to the sidewalk. They said cycling in the current unprotected lanes fails to save them from swerving vehicles, parking vehicles and those dropping off passengers, or making unexpected turns.

Not everyone was necessarily part of an organized effort. Chris Bunting said he had heard about the event earlier that day during a radio show he hosts, took the long way home, and decided to jump in.

For others, road safety advocacy is a daily task. Roger Rudick was one of the human lane dividers on Thursday evening, but has been to others as a reporter for Streetsblog San Francisco.

“You’ve got to move the cars and give the bikes the equivalent of a sidewalk, some place that’s truly safe,” he said. “What I’m doing feels a little dangerous, but we’re forced into danger all the time.”

Asked if she was worried, Persico said jovially, “slightly, but I can jump on a hood.”

No injuries have been reported as a result of the bike lane barricade.

Matt Brezina, one of the organizers of the protest, said the city has been slow to make infrastructure improvements, except in extreme cases – he pointed to two cyclists’ deaths in the same day that prompted mayoral action.

“I hope it doesn’t take a death on every corner to put a protected bike lane in,” he said. “I’d hope that we don’t have to wait until more people day. We know how dangerous it is.”