Dangerous dense fog can occur anywhere in North Carolina, although it is more frequent in our mountain and piedmont regions. When present, dense fog can be a contributing factor to crashes involving cars, trucks, motorcycles and other vehicles. Multiple vehicle pile ups can happen as oncoming motorists crash into vehicles which crashed previously and are stopped on the road. This is what happened on Easter Sunday, March 31, 2013.

That afternoon heavy fogwas the major contributing factor triggering a 95-carpile up on I-77 that left three people dead and 25 injured. National news first reported the collision occurred at the North Carolina – Virginia state line. (It turned out the crash occurred a bit farther north in Fancy Gap, Virginia.)

The crash prompted the North Carolina Department of Transportation’s Transportation Mobility and Safety Division to study fog related crashes in the state and publish a report of their findings. The report was published in July 2013, and concluded the number of fog and other weather-related crashes might be reduced with “the continuation of information sharing across all of the NCDOT departments and the newsmedia outlets on the existing weather-related forecast maps/centers…”

NCDOT also worked with scientists at UNC Asheville and UNC Charlotte on ways to increase the use of weather data for traffic safety. The scientists sought to develop localized visibility predictions for traveler information systems. They also explored technologies for alerting travelers to weather such as fog that could affect visibility. One of the technologies this team worked on was an algorithm to produce real-time fog depth imagery using satellite data from the National Oceanic and AtmosphericAdministration (NOAA).

More information about foggy conditions can certainly help motorists avoid foggy conditions. But what can drivers do when they find themselves in dense fog? Here ares ome recommendations from the NCDOT:

• Use low-beam headlights and your defroster to increase visibility – regardless of whether it is day or night. High beams could reflect off fog decreasing visibility.

• Stay alert and be ready for sudden stops. Allow at least twice the normal following distance between vehicles.

• Signal for turns and brake earlier than usual as you near a turn or stop.

• Be patient and do not pass lines of traffic.

• Allow yourself more time to get where you're going. Drive at least 5 to 10 mph slower than the speed limit on wet pavement.

The National Weather Service also recommends:

• Make your vehicle visible to others both ahead of you and behind you by turning on your headlights (use low beam). This makes your vehicle more visible from both the front and rear as your tail lights will also be on.

• Use fog lights if you have them.

• Leave plenty of distance between you and the vehicle in front of you to account for sudden stops or changes in the traffic pattern.

• To ensure you are staying in the proper lane, follow the lines on the road with your eyes.

• In extremely dense fog where visibility is near zero, the best course of action is to first turn on your hazard lights, then simply pull into a safe location such as a parking lot of a local business and stop.