FORT SMITH, Ark. -- A Fort Smith teenager remains in the hospital with massive brain injuries after crashing his scooter.

Zackery Clayton, 18, was driving the scooter Tuesday along Old Greenwood Road in Fort Smith when he lost control and hit the curb, throwing him and his passenger off.

The passenger, Whitney Rios, 18, suffered only minor cuts.

“There were two helmets located at the scene,” said Jarrard Copeland of the Fort Smith Police Department. “But it’s not believed that either of these persons were wearing a helmet.”

Arkansas law makes helmets optional for anyone 21 or older on a motorcycle or scooter but law enforcement officials strongly encourage it.

“A lot of people won’t even ride a bicycle without a helmet because of the potential for head injuries,” said Copeland. “We definitely recommend that people wear helmets if they’re riding a motorcycle or scooter.”

Police are allowed to ticket anyone under 21 caught on a motorcycle or scooter without a helmet.

Arkansas officials said the number of motorcycle and scooter accidents are rising because more inexperienced drivers are operating those vehicles.