The Unit may not issue a permit or authorize use of a book permit, if it determines that the proposed movement would constitute an unreasonable hazard to other highway traffic or be unreasonably detrimental to highway surfaces or structures. The Unit may not issue a blanket hauling permit or a special hauling permit, or authorize use of a book permit, if the vehicle and its load can be dismantled or disassembled or hauled in such a way that moves can be made within the size and weight limits imposed by the laws of Maryland. The Unit may not issue a special hauling permit for the movement of any overweight vehicle unless the vehicle: Has five axles or more and is registered for at least the maximum gross weight in its State of registration; or Is special mobile equipment. The Unit may not authorize the use of a book permit for movement of any overweight vehicle unless the vehicle: Has five axles or more and is registered in Maryland for the maximum allowable gross weight; or Is registered as special mobile equipment in Maryland and displays special mobile equipment plates issued by the Motor Vehicle Administration of Maryland. The Unit may not issue a special vehicle permit when the: Special vehicle reasonably can be disassembled to comply with the size and weight limits of Maryland law; or Permit movement would constitute the regular and continuous movement of a special vehicle. The Unit may not issue an exceptional hauling permit unless the vehicle: Is a combination of vehicles that has six or more axles; and Has a minimum front to rear centerline axle spacing of not less than 50 feet.