What is the purpose of projection marker boards on vehicles with rear overhang?

• A. To indicate the length of the overhang to other road users
• B. To indicate the vehicle's height
• C. To indicate load weight
• D. To indicate speed

Answer: (B)

Projection marker boards are placed on vehicles with rear overhang to show the vehicle’s height to drivers behind. This provides a clear visual cue about how tall the vehicle (including any load) is, helping other road users judge whether there is enough clearance under bridges, tunnels, or other overhead obstacles, and to safely plan overtaking or following distances. They aren’t about how long the overhang is, the load weight, or the vehicle’s speed, which is why this marker’s purpose is height indication.