Traffic on Highway 108 was backed up for about four miles for nearly an hour in the Jamestown area Wednesday afternoon.
The CHP says Patrick Maddox of Turlock was driving a pickup there and caused the accident, when he either fell asleep or had a seizure and drifted into oncoming traffic. CHP Spokesman Tom Wills says the two elderly women in the other car had to be taken to Modesto for treatment. Maddox was taken to a local hospital.
The CHP says everyone involved in the head on collision was wearing a seatbelt.