A 47-year-old man died this morning when his motorcycle collided with a truck on the H-1 freeway westbound near the Waipahu off-ramp.

Positive identification is pending.

The fatal crash occurred at approximately 8:10 a.m. today.

Police said the motorcyclist, of Waipahu, was traveling west on the H-1 when he rear-ended a vehicle.

City Emergency Medical Services officials said the man was pronounced dead at the scene.

Police said speed was a factor. It is unknown at this time whether alcohol or drugs were involved.

This is the 11th traffic-related fatality on Oahu compared to nine at the same time last year.

Police closed the two left lanes of the H-1 westbound before the H-2 northbound off-ramp as they investigated, and the ZipMobile was stopped near the H-1/H-2 split due to the accident, according to the state Department of Transportation. The ZipMobile resumed closing the zipper lane at about 11 a.m., according to the DOT.

Morning traffic in the area was severely congested and motorists were advised to seek alternate routes.