State troopers and emergency crews responded to the scene, on southbound I-5 at 220th Street SW, at about 7:25 a.m. after receiving reports of a pedestrian struck on the roadway, said Leslie Hynes of Snohomish County Fire District 1.
The man was pronounced dead at the scene. His name was not released pending notification of his next of kin.
Few other details were immediately available.
According to early reports, the man got out of his car and was struck by the semi truck. A preliminary investigation found that he ran into traffic and was hit in the second southbound lane.
The truck driver stopped after the accident and was released after questioning. No charges are pending since the truck driver was not at fault, the State Patrol said.