The accident happened about 12:30 a.m. in the southbound lanes of I-5 near 164th Street SW in Snohomish County.
The teen was attempting to pass a semi when he hit a car that was parked on the shoulder. That car was pushed into traffic; a UPS truck traveling on the highway was unable to stop and struck the car. The UPS truck also hit another car in its attempt to avoid hitting the first car.
When the dust settled, the chain of accidents blocked the southbound lanes of I-5. The lanes were reopened about 2 a.m.
The driver of the original car that attempted to pass on the shoulder was the one person injured. He was taken to Swedish Hospital.