Driving Safely in Fog
Fog can transform familiar roads into a challenging and hazardous environment for drivers. Dense fog, especially common in the fall and early winter, significantly reduces visibility and increases the risk of accidents. Idaho Office of Emergency Management (IOEM) encourages everyone to understand fog and how to handle conditions to stay safe on the road.
Fog forms when air cools rapidly overnight under clear skies and with sufficient moisture. This often occurs in valleys due to a process called cold air drainage, where cooler air sinks and collects at lower elevations. Dense fog is especially hazardous during early morning hours when visibility is at its lowest.
Driving in foggy conditions can be unpredictable. One moment your view might be clear, and the next you could find yourself in thick, blinding fog. This rapid change demands caution and preparation.
Advisory Alerts to Know
The National Weather Service issues two types of fog advisories to help you prepare:
- Dense Fog Advisory:
Issued when widespread dense fog reduces visibility to a quarter-mile or less, making travel hazardous. - Freezing Fog Advisory:
Issued when fog forms at or below freezing temperatures, creating icy road conditions. The tiny liquid droplets in the fog can freeze instantly upon contact with surfaces, increasing the risk of accidents.
Tips for Driving in Fog
- Slow Down
Fog can make it difficult to judge distance and speed. Reduce your speed and allow extra time to reach your destination. - Use Low-Beam Headlights
Low-beam headlights improve your visibility and make your vehicle more noticeable to others. Avoid using high beams, as they can reflect off the fog and worsen visibility. If your vehicle has fog lights, use them for added safety. - Increase Following Distance
Maintain a larger gap between you and the vehicle ahead. This extra distance gives you more time to react to sudden stops or changes in traffic. - Stay in Your Lane
Use road markings as a guide. Keep your focus on the painted lines to make sure you stay in the proper lane. - Avoid Stopping on the Road
If fog becomes so dense that you can’t see, it’s safer to pull off the road. Follow these steps:- Turn on your hazard lights.
- Move to a safe location, such as a parking lot or driveway, if possible.
- If stopping on the roadside is your only option, pull off as far as possible, turn off all lights except your hazard lights, and set the emergency brake. Avoid keeping your foot on the brake pedal to prevent other drivers from mistaking your vehicle for one that’s moving.
When the fog rolls in, slow down, stay focused, and prioritize safety. It’s always better to arrive late than not at all.
For additional information about fog safety, check out some of these resources: