LAGUNA BEACH, Calif. — Chance Gaul cannot drive a car yet. He is only 14. But he is already the fastest thing on wheels around here.

While Porsches and Mercedes-Benzes precariously descend the windy canyon roads here at 25 miles per hour, Chance bombs down at 40, sometimes even 60 m.p.h. on his skateboard, savoring the sea breeze on his face. But this may be his last ride here.

The future of downhill skateboarding is in jeopardy in the region where the sport was born, with bans spreading across Southern California and lawmakers questioning whether people — teenagers mostly — should be barreling downhill at 60 m.p.h. with very little between them and the pavement.

Laguna Beach is set to become the latest city to severely restrict high-speed skateboarding, sometimes known as “bombing hills,” following other coastal cities like Malibu and Newport Beach. Once a final vote is taken on Tuesday, eight canyon roads will almost certainly be entirely off limits, while others will remain open on a six-month trial basis, after which they, too, may be closed to skaters.