GLENDORA — An investigation is ongoing into a crash between a sheriff’s patrol car and a motorcycle on the Foothill (210) Freeway early Tuesday that sent the rider to a hospital with moderate injuries, authorities said.

The crash took place about 6:20 a.m. on the westbound 210, just east of Lone Hill Avenue, California Highway Patrol officer Ed Ed Jacobs said.

A sheriff’s deputy assigned to the sheriff’s East Los Angeles Station was traveling in the fast lane at 5 to 10 mph in “heavy commute traffic” prior to the collision, CHP Sgt. John Escobedo said. The motorcyclist, a 56-year-old Fontana man, was riding his Kawasaki Vulcan motorcycle in the carpool lane at about 30 mph.

The left side of the patrol car collided with the right side of the motorcycle and rider, though it was not immediately clear which vehicle was at fault, Escobedo said.

The motorcycle went down, and the rider suffered apparently moderate injuries to his right shoulder and right side, officials said. He was taken to Foothill Presbyterian Hospital in Glendora for treatment.

Officials issued a Sig Alert for the carpool and fast lanes of the westbound 210 for about an hour and a half as they investigated the crash scene.