“What we had in mind was the short-distance commuter,” said Kristin Olsen, the California assembly member who sponsored the measure, adding that the law can be amended by municipalities and private property owners who want to restrict use of hoverboards.

“Riding one of these in Santa Monica is going to be different than in Modesto,” she said.

But the biggest beneficiaries of the new law are likely to be people like Madison Hirsch, a 14-year-old sophomore at Tamalpais High School here. She saw a friend riding a hoverboard over the summer and wanted one desperately, but her parents refused to buy her a $750 one she coveted from Future Foot. So she used money saved from birthdays and Hanukkah to buy one, and since September she has been riding it around town and at her school. One woman scolded her for riding it at the mall, demanding she get off and walk.

“I didn’t,” Madison said. “I can ride faster than she can chase me.”

This month, the police department at the University of California, Los Angeles, said hoverboards would not be allowed on walkways and in hallways after pedestrians complained about collisions. In London, the authorities recently reminded residents that the boards are banned from public streets and roadways because they are dangerous.

The new California law mandates that hoverboard users on bikeways be at least 15 and wear the same gear required when riding a bike. At Stevenson School in Pebble Beach, students recently received an email reminding them of the rules. “If they see you without a helmet, they will take your hoverboard away,” said Joseph Cohen, 15, a sophomore.