Sections 621.207 and 621.504 of of the Texas Transportation Code restrict a vehicle and its load to a height of no more than 14 feet, unless an oversize/overweight permit is obtained from the Texas Department of Motor Vehicles (TxDMV). Furthermore, it is unlawful to operate a vehicle over or on any bridge or through any underpass or similar structure unless the height of the vehicle, including its load, is less than the vertical clearance of the structure as posted by the Texas Department of Transportation (TxDOT).