Construction and low - clearance vehicles required to take special precautions at grade crossings--Violation as misdemeanor

No person may operate or move any crawler type tractor, steam shovel, derrick, roller, or any equipment or structure having a normal operating speed of ten or less miles per hour or a vertical body or load clearance of less than one - half inch per foot of the distance between any two adjacent axles or in any event of less than nine inches, measured above the level surface of a roadway, upon or across any tracks at a railroad grade crossing without first complying with §