Speed limits are listed for ideal weather conditions and foggy roads can quickly become dangerous. Highway Patrol says drivers need to be extra alert as heavy fog can conceal fallen tree branches, car wrecks, or other road blocks until the driver is very close. Law enforcement suggests giving yourself extra time to get where your need to be if fog is in the forecast.
Benjamin Seibert of the Mississippi Highway Patrol says, “I can’t preach driving slow enough. The speed limit is for clear conditions, naturally if you get out there and run 65 to 70 mph in the fog, you’re going to have problems. Need to be prepared in the fog that the roadway may not be clear, there might be another accident, there might be a stalled vehicle, there’s all kinds of other things, and if you are in a collision, you’d naturally rather do it at a slower speed.”
Again, Highway Patrol asks drivers to slow down in foggy weather.