What does a posted sign warning of a low underpass or bridge indicate?

• A. A detour to the right
• B. Low clearance ahead; do not proceed if your vehicle height is above the limit
• C. The speed limit is about to increase
• D. There is a pedestrian crossing ahead

Answer: (B)

Low clearance signs warn that there is limited vertical space ahead. They require you to compare the posted height with your vehicle’s height, including any antennas or racks. If your vehicle is taller than the limit, you must not proceed and should find an alternate route. This is the best answer because the sign’s purpose is to prevent tall vehicles from entering and getting stuck or causing damage.

Why the other options don’t fit: a detour sign points you to a different route due to road closure, not a height restriction; a sign about speed limit indicates changing speeds, not vertical clearance; a pedestrian crossing sign indicates people crossing, not space limitations for vehicles.