Commercial Drivers must know the Maximum Height
No vehicle, including its load, may be more than 14 feet high.
This limit does not apply to emergency vehicles or utility repair equipment.
Even though you know the height of your vehicle or load, always use caution to ensure adequate clearance is available, particularly when driving in unfamiliar areas or in bad weather.
When approaching a tunnel or overpass on a new route, with no clearance signs visible, safely pull off the road and determine the clearance height.
Ice, snow, or road repairs may decrease a clearance that is normally sufficient.