Low clearance
What does it mean?
An overhead obstruction ahead has the vertical clearance shown. This illustration reads 12 feet 6 inches, but the number on the sign you encounter is the one to compare with your vehicle's full height, including its load.
What to do when you see it
- Know the height of the vehicle and anything carried on top.
- Use a safe alternate route if the vehicle will not fit or its height is uncertain.
- Follow any clearance signs assigned to a particular lane or part of the structure.
How to recognize it
- Yellow diamond with a height in feet and inches.
- An upward arrow and a downward arrow frame the height.
On the road
You are driving a rented moving truck toward this warning. You check the truck's stated height before committing to the approach and use another route if there is not enough clearance.
Don’t confuse it with
Narrow bridge
Narrow Bridge concerns horizontal room; Low Clearance concerns vertical space.
Road narrows
Road Narrows warns about roadway width and does not state an overhead height.
Put the meaning into practice
The related quiz includes this sign and other study questions. State practice can also cover local rules; it is not an official DMV exam.
Common U.S. sign recognition, reviewed October 3, 2026. Actual sign values, additional plaques and local rules can change how you should respond.