FRESNO, Calif. (KFSN) -- Thick fog on Friday made for a mess on the roads through much of the Central Valley, especially during the morning commute.
A Cadillac was almost unrecognizable after its 10 a.m. collision with a big rig on Shaw Avenue in the Biola area, west of Fresno.
California Highway Patrol officers say they believe the driver of the 18-wheeler adjusted for driving in the fog. He was going slower than the speed limit and had his headlights on.
But the man in the Cadillac misjudged the conditions.
"That vehicle entered the opposing eastbound lane in order to pass another vehicle within the fog," said CHP public information officer Mike Salas. "Fog at this time was about a 200-foot or less visibility. (He) did not see that approaching big rig."
Damaged cars littered Central Valley freeways Friday morning.
Eight vehicles sustained damage in one crash on Highway 99 south of Manning, where Caltrans cameras could barely even catch a glimpse of the road.
Traffic on the freeway was snarled in both directions late into the morning, and visibility was still reduced past noon.
In the South Valley, a major collision at Highway 198 near Highway 43 also slowed traffic.
CHP officers paced cars there to keep drivers safer in the fog.
"We do have all our available officers out on patrol with the anticipation that we are going to have multiple calls," Officer Salas said. "Unfortunately, this was one of those mornings."
Friday was one of the most dangerous on the road this winter.
CHP officers say when you notice thick fog, you should try not to drive unless absolutely necessary.
If you have to drive, make sure to manually turn on your headlights.
Officers say a lot of automatic headlights don't turn on in the fog and they saw a lot of people driving without headlights Friday morning.
And of course, drive as carefully and slowly as possible.
"Regardless of the size of the vehicle, driver error is the number one cause of a crash," Salas said. "Again, speed is the number one concern. Slow down. We just can't stress that enough."
As of Friday afternoon, CHP officers said all of the crash victims survived.
But the man who hit the big rig on Shaw was still in critical condition.