The northbound lanes of Interstate 405 south of Woodinville were closed for more than two hours early Saturday after a body was found on the roadway.
Washington State Patrol trooper Chris Webb said the person might have jumped from a freeway overpass about 5 a.m.
The agency later identified the body as that of a 16-year-old Bothell boy.
At first, it was believed he had been struck by several vehicles, but Webb later reported that a single vehicle had hit the victim and that the driver returned to the scene.
Traffic in all northbound I-405 lanes was diverted off the freeway at Northeast 160th Street until about 7:30 a.m.
The State Patrol did not release the name of the boy, because he was a juvenile.
The Seattle Times and staff