The 27-year-old San Francisco man was hit by a vehicle that had been traveling south on I-280 just north of Eastmoor Avenue at about 4:30 a.m., and the vehicle fled the scene, according to the CHP.
The incident was reported at 4:33 a.m., when another vehicle struck the man.
According to the CHP, the number of vehicles that struck the man is still under investigation and a newer blue Prius was possibly involved.
North County Fire Authority personnel responded to the scene and located the man under one of two vehicles that had been involved in a collision.
The first arriving chief officer on scene reported one of the vehicles was on the right shoulder and another was in the two middle southbound lanes of the freeway.
The fatal crash blocked all but one lane of southbound traffic for several hours this morning, and a Sig-alert was issued at 4:54 a.m. That advisory was canceled when all lanes reopened at 7:57 a.m.