Reports of a body on the roadway were called in around 2:10 a.m., CHP Officer Tom Stewart said.
Investigators determined the incident was a vehicle versus pedestrian hit-and-run, but have not confirmed how many vehicles were involved, Stewart said. No suspects have been arrested.
The Nos. 3 and 4 lanes on the southbound side of the highway were closed for an investigation and reopened around 4 a.m., Stewart said.