The Honolulu medical examiner’s office is trying to identify a man who died Saturday while walking along Kamehameha Highway in Haleiwa.

The man was struck by a vehicle about a quarter-mile south of Pohaku Loa Way just after 2 a.m.

Police said the driver, a Haleiwa man, left the roadway for an unknown reason and struck the pedestrian, who died at the scene.

Police cited excessive speed as a possible factor.

This is the 40th traffic fatality on Oahu for 2015, compared with 48 at this time last year.