This rule shall not apply to a closed highway which is frozen. A highway is considered "frozen" if the air temperature is 32 degrees Fahrenheit or below and no water is showing in the cracks of the road. Alternatively, if the air temperature is 32 degrees Fahrenheit or below and there is water showing in the cracks of the highway, the highway will be considered "frozen" if the adjacent gravel driveways, shoulders, or lawns remain frozen.
17-229 C.M.R. ch. 308, § 4