Driving in fog, and when to pull over

Fog, smoke, blowing snow and blowing dust are counted together as low visibility. From 2019 to 2023, those conditions led to an average of about 32,900 crashes a year, injuring about 11,300 people and killing 488. They made up 13% of the deaths in weather-related crashes. Snow, ice and fog together also cause an estimated 23% of the unexpected delay on the nation's highways.

The lights

• Turn on the low beamsThey make the car visible ahead and behind, because the taillights come on with them.
• Use fog lights if the car has them
• Keep the high beams offThey cause glare, which makes it harder to see the road ahead.

Speed and space

• Slow downAllow extra time to get where you're going.
• Leave plenty of room behind the car in frontThe space covers a sudden stop or a change in the traffic ahead.
• Follow the lines on the road with your eyesThey keep you in your lane when you can't see far.

When you can't see at all

• Turn on the hazard lights first
• Pull into a safe place, such as a business's parking lot, and stop
• With no lot or driveway, pull off the road as far as you can
• Once stopped, turn off every light but the hazard lights
• Set the parking brake and take your foot off the brake pedalWith your foot off the pedal, the brake lights go dark, so drivers behind you don't take them for a moving car and follow them into you.

The two fog advisories

Your local National Weather Service office issues a Dense Fog Advisory when widespread dense fog develops. Visibility then often drops to a quarter of a mile or less, and travel gets difficult. Take extra care on the road, or skip the drive if you can.

A Freezing Fog Advisory means fog has formed while surface temperatures are at or below freezing. The tiny droplets in the fog can freeze the moment they touch a surface, including the car and the road. Visibility in freezing fog is typically a mile or less.