The driver rear-ended the other vehicle at about 5:30 p.m. on southbound Interstate Highway 880 north of 16th Avenue, Officer Ralph Caggiano said.
He appears to have suffered an epileptic seizure, Caggiano said. The first vehicle's engine caught fire, and the flames traveled to the second car, according to Caggiano. Both vehicles were engulfed in flames by the time CHP officers arrived about eight minutes later.
The driver was still in the first vehicle when officers arrived, and when he got out of the car, the back of his head was on fire. A CHP officer approached the man to try to help, but the man jumped back into the burning car.
He was apparently delirious from the crash and the seizure, Caggiano said. The CHP officer was able to subdue the man and pull him from the car.
The man suffered some burns to the back of his head and was taken to Highland Hospital, Caggiano said. He did not appear to be seriously injured.
A third car was also bumped from behind in the collision, but the driver left the scene -- probably because the contact was minor, Caggiano said.
The left three lanes of southbound I-880 were closed for about an hour and 15 minutes while officers investigated the crash, according to the CHP.
Traffic that was already backed up for the evening commute was further delayed as a result, Caggiano said.