SACRAMENTO, Calif. (AP) — Californians soon won’t have to wear helmets while zipping around on motorized scooters.

Gov. Jerry Brown signed legislation Wednesday requiring helmets only for people under age 18. It’s a win for companies such as Bird and Lime that operate the popular scooters in major cities across California and the country.

The scooters, which the law says can’t go faster than 15 miles per hour, have delighted riders but rankled motorists, pedestrians and city officials.

San Francisco earlier this year banned the scooters because of concerns about riders not wearing helmets, riding on sidewalks and violating other laws. In August it awarded permits for a pilot program to several scooter companies but shunned companies Bird, Lime and Spin, which had previously operated in the city. Bird backed the no-helmet law.

Bird operates in more than a dozen California cities, including Berkeley, San Diego and San Jose.

The law takes effect Jan. 1.

Republican Assemblyman Heath Flora of Ripon, the bill’s author, said standup scooters can alleviate congestion on California’s roads and will help the state meet its climate change goals by reducing car emissions.

He argued adults should be free to choose whether or not they want to wear a helmet when riding the scooters, even though companies highly recommend them and they are proven to enhance safety, according to the bill analysis.

Flora’s bill also lets cities authorize the scooters on roadways with speed limits up to 35 mph (56 kph). That’s up from 25 mph (40 kph) under current law.