The crash occurred at about 1:40 a.m. at the off-ramp to Central Avenue from westbound Highway 80 after the vehicle was apparently traveling with a flat tire on the highway, CHP officials said.
The person's identity was not immediately being released this morning by the Contra Costa County coroner's office.
The Central Avenue off-ramp was closed for nearly seven hours as a result of the fatal crash and reopened at about 8:25 a.m., CHP Officer Kevin Bartlett said.
