Warning sign · MUTCD W12-2
Low Clearance
A bridge, tunnel or overpass ahead is low. The number on the sign is the maximum vehicle height that can pass safely.
- Shape
- Diamond (square turned on its corner)
- Color
- Yellow background, black letters and border
What to do
Know the height of your vehicle, including any load or roof equipment. If you are taller than the number, do not proceed; turn onto another route well before the structure.
Where you see it
Before low bridges, tunnels and overpasses, often with a repeat sign at the structure itself.
Test trap
The number is the height of the clearance, not a speed limit or a weight limit. Drivers of trucks, RVs and rental vans cause many crashes by assuming they will fit.
Memory tip: If you are taller than the number, you do not fit.
Practice question
This sign means:
- A low bridge or underpass is ahead
- The speed limit drops ahead
- Trucks must use the left lane
- A tunnel is closed to trucks
Answer: A. Low Clearance warns of a low bridge or overpass; the number is the maximum safe vehicle height.
West Virginia Driver's Licensing Handbook, p. 46