Police said excessive speed may have contributed to a crash that killed a motorcyclist on the H-1 freeway near Palama on Sunday night.

Traffic investigators said a 51-year-old Aiea man was operating a 1994 Suzuki Intruder motorcycle in the Waianae-bound lanes of the freeway when it veered into the path of a 2003 Lincoln Navigator and the vehicles collided, causing the motorcycle to fall.

The collision happened about 8:50 p.m., two-tenths of a mile west of the Palama Street offramp.

The motorcycle driver suffered massive head injuries and was pronounced dead at the scene, police said. He was not wearing a helmet. Officials did not disclose his name yesterday.

The driver of the Navigator, a 60-year-old Waipahu man, was not hurt.

Police closed the H-1 freeway’s westbound lanes for several hours as traffic investigators examined the crash scene.

It was 11th traffic fatality on Oahu this year, compared to nine at the same time last year.