Adult Californians soon won’t have to wear helmets while riding motorized scooters.

Gov. Jerry Brown signed legislation Wednesday requiring helmets only for people under age 18.

It comes as scooter rental services provided by companies like Bird rise in popularity across California, delighting riders but rankling motorists, pedestrians and city officials.

Long Beach approved a roughly four-month pilot program for several scooter companies open shop in the city, beginning in June. Scooter use is limited to those over 18, and the city did require riders to wear helmets while operating on city streets.

San Francisco banned the scooters earlier this year because of concerns about riders not wearing helmets and violating other laws. In August it awarded permits for a scooter pilot program to several companies but did not give one to Bird, Lime or Spin.

Bird backed the no-helmet law.

The law also sets a maximum speed of 15 miles per hour for the scooters, the same limit approved by Long Beach leaders.

The state law takes effect Jan. 1.

RELATED COVERAGE: