Casa Grande High School senior Sydney Leff had never before Wednesday ridden a bicycle to the east Petaluma campus.

But in celebration of International Walk and Roll to School Day on Wednesday, Leff and junior Bridget Kiernan hopped aboard a mountain bike and cruiser, respectively, and peddled to school.

"It was fun," Leff said as she stopped at a table laden with fruit and baked goods meant to reward students for taking the plunge of riding or walking to school instead of driving.

"I guess that's why they do it, to make people realize they should. It worked on me," Leff said.

More than 70 schools across Sonoma County were expected to participate in the annual event that is staged to give both students and parents a sense of what life could be like if they hung up the car keys.

The event can help allay parents' fears of their children riding bikes or walking to school, while also giving officials a better sense of what it takes to keep people safe on sidewalks and streets, said Tina Panza, director of Safe Routes to Schools, an organization that spearheaded the event.

"I personally think that there are more risks to not encouraging healthy, active lifestyle than there are for kids biking and walking to school," she said.

At Petaluma City Schools, campuses are given the choice of whether to promote the event or not.

"We have no formal board policy," said Jane Escobedo, assistant superintendent. "In the past, there has been some concern on the west side of town because there are not bike paths everywhere and that kind of thing. There has been some concern in the past, but the city is putting in more bike paths, so we are kind of letting people choose."

In Forestville, parents and teachers met at a nearby park and walked to the campuses of Forestville School and the Forestville Academy together, said organizer and physical education teacher Kirsten Beseda.

"Forestville is a funky little town and there aren't the easiest routes to go through," she said.

Beseda uses the event to teach students rules of the road and safe walking tips.

In Cloverdale, more than 30 percent of the students at Jefferson school walked, rode or scooted to school, according to Blythe Houg, a Jefferson parent who helped organize the event.

"Getting them out there and moving around is important," she said, noting that parent participation was up this year as well.

"It was a nice morning, so that adds to it," she said.

At Casa Grande, a contingent of cyclists rolled onto campus with now-retired professional cyclist Steven Cozza of Petaluma who agreed to lead a bike train that picked up riders at pre-determined locations Wednesday morning.

"I think the change is going to come in baby steps," Cozza said of the default mode of driving everywhere, including to school. "People should make it a goal to ride one day a week, then maybe two days a week."

Organizers include Safe Routes Sonoma County, Sonoma County Bicycle Coalition, Network for a Healthy California, Kaiser Permanente, Eco2School and Measure M.

Final participation tallies are expected Friday.

Staff Writer Kerry Benefield writes an education blog at extracredit.blogs.pressdemocrat.com. She can be reached at 526-8671, kerry.benefield@pressdemocrat.com or on Twitter @benefield.