While riding his motorcycle between slowed Highway 101 traffic Wednesday morning south of Petaluma, a Petaluma man was hit by a car when the driver changed lanes, according to the CHP.

Rider Michael Colglazier, 23, was thrown onto the highway shoulder.

He was taken to Santa Rosa Memorial Hospital with moderate injuries, said the CHP.

The southbound collision, south of Kastania Road, occurred at about 6:50 a.m.

The morning commute was building and the collision created extensive traffic congestion, said the CHP.

Colglazier had been traveling at about 40 mph between the two highway lanes. Traffic was moving at about 10 mph, according to reports.

Driver Robert Bowman, 33, of Fairfax said he didn't see the rider coming up between the lanes.

He was beginning to move into the next lane when he struck the motorcycle.