BOULDER COUNTY, Colo. (CBS4) – A 29-year-old man from Westminster was killed when the motorcycle he was driving collided with a car on Highway 119 on Saturday in Boulder County.

The Colorado State Patrol said the man on a Harley-Davidson was traveling eastbound behind four other vehicles and attempted to pass them all by crossing the double-yellow center line. After passing three vehicles he attempted to return to the eastbound lane but collided with the lead vehicle, a 2009 Toyota Yaris.

The man, whose name hasn’t been released, was thrown from the motorcycle and then hit by a 2007 Toyota FJ Cruiser traveling westbound.

The motorcyclist was pronounced dead at the scene. He was wearing eye protection but no helmet.

The driver of the Yaris, Irene Pritsak-Savage, 59, of Nederland, was not injured. The driver of the FJ Cruiser, Sean Slavin, 39, of Broomfield, and his two passengers also were not injured.

Police are not sure if drugs or alcohol contributed in the crash. Excessive speed is being investigated as a possible contributing factor.

Highway 119 was closed at the crash location for approximately four hours during the investigation.