One minute, you are driving along with normal or near normal visibility, and you can see a few hundred yards in front of your vehicle. Then, suddenly with little or no warning, you can barely see two car lengths in front of your vehicle. If you see taillights, it's probably too late to attempt to stop.
This type of nightmare driving condition is common throughout the East Coast and the Appalachians in Georgia, and Easter Sunday, it occurred on the border of North Carolina and Virginia, as fog closed around dozens of motorists, causing fatal, chain reaction accidents. Three people were killed and 25 were injured in car and truck accidents involving 95 vehicles.
Fog and highway driving makes for a particularly deadly mix, because even if you slow enough to avoid hitting another vehicle, and manage to stop, you have no assurance that any vehicles following yours are going to stop in time. The Virginia State Police reported that there were 17 accidents within a 1.5-mile stretch of I-77 through Fancy Gap Mountain.
The crash led to a 16-hour closure of the southbound lanes while emergency personnel removed the damaged and destroyed vehicles. The Charlotte Observer reported that this was the fifth fog related multi-vehicle crash that has occurred on this section of I-77.
The fog is dangerous enough on this part of the interstate that there are warning signs, which had been operational Sunday. The state police reported that visibility dropped to about 100 feet in a matter of seconds as cars descended a steep grade.
At 65 mph, a vehicle is moving at nearly 88 feet per second, meaning that drivers would have had slightly over one second to react and stop their vehicles.
Over the years, at least five drivers have been killed on this highway and in 2010, 75 vehicles were involved in a mass crash that left two dead.
Source: Charlotte Observer, "I-77 open after 95-vehicle crash that killed 3," Steve Lyttle, April 1, 2013