Don’t Get Lost in the Fog When Driving on Sacramento Valley Roadways


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District:  District 3 - Marysville
Contact: Gilbert Mohtes-Chan
Phone:  (530) 741-4571 Cell: (530) 682-6145



MARYSVILLE — Traveling safely through heavy fog blanketing local state highways this holiday season can be as simple as following a 3-2-1 countdown or opening your window to listen for traffic, according to Caltrans.

Throughout the winter and early spring, the greater Sacramento region often finds itself shrouded in thick ground fog, better known as tule fog, which emerges after the rains saturates the soil and then is rapid cooling at night. Nearly three in four fog-related traffic collisions are connected to motorists driving too fast, statistics indicate. These collisions also result in the highest fatality rates.

To help motorists navigate safely through pea soup weather, Caltrans offers these driving tips:

  • Reduce your speed to ensure a safe stopping distance.
  • Drive with headlights in low beam. Never drive with only the parking lights or fog lights.
  • Use extra caution when crossing traffic or busy intersections, especially in dense fog.
  • Lower your window and listen for traffic you can't see.
  • Use windshield wipers and your defroster to improve visibility.
  • Be patient and don't pass long lines of traffic.
  • Use the boundary lines or roadway edge on your right as a guide.
  • Unless really necessary, don't stop along the freeway or highway.

When looking to exit, the solid white line on the shoulder will veer to the right, breaks for a few feet and then resumes along the ramp. Also, highways prone to fog will have markers that follow a 3-2-1 countdown dot pattern to let motorists know there is an exit ahead. On the right shoulder, drivers will see three reflective markers 2,100 feet before the exit, two markers at 1,400 feet and one marker at 700 feet.

Caltrans District 3 maintains more than 4,385 lanes miles of state highway in 11 Sacramento Valley and Northern Sierra counties. Caltrans will issue updates on Twitter updates on Twitter @CaltransDist3 and on Facebook at CaltransDistrict3. For real-time traffic, click on Caltrans’ QuickMap or download the QuickMap app from the App Store or Google Play.