The crash was reported at about 7 a.m. on Highway 116 at the intersection of Stony Point Road.
The victim is a 59-year-old Guerneville man. He was pronounced dead at Santa Rosa Memorial Hospital and his identity is being withheld until his next-of-kin are notified, CHP Officer Jon Sloat said.
The driver of a Honda Accord, Jorge Noe Valencia Figueroa, 33, pulled out of the parking lot of My Market at the southwest corner of the Highway 116 and Stony Point Road intersection and came directly into the path of the 2008 Honda motorcycle, Sloat said.
The motorcycle was traveling east on Highway 116 and it appears the Guerneville man lay the motorcycle down but he was run over by the Honda, according to Sloat.
The first CHP officer at the scene and witnesses tried to rescue the man from beneath the Honda, Sloat said.
The motorcyclist was eventually extricated by Rancho Adobe Fire Protection District personnel and given CPR before he was taken to the hospital, Sloat said.
Figueroa, a Cloverdale resident, was detained and taken to the Rohnert Park Department of Public Safety for questioning, Sloat said.
Records indicate Figueroa has four prior convictions for driving without a license, and investigators are working with the Sonoma County District Attorney's Office to determine if charges will be filed against him, Sloat said.
Alcohol does not appear to be a factor in the collision, which closed Highway 116 until around 8:40 a.m.