Which color flag marker should a vehicle use if its load exceeds its length by 1 meter?

The correct choice for marking a vehicle whose load exceeds its length by 1 meter is a red flag. The use of a red flag is standard practice in many jurisdictions as it signifies caution and alerts other drivers to protruding loads that may pose a hazard. This practice is essential for maintaining safety on the road, as it helps to prevent accidents by making other road users aware of the potential danger of the extended load.

In many regulations, including those related to the Land Transportation Office, specific colors are designated to indicate different conditions or hazards. The red flag serves as a clear, universal signal that draws attention to an unusual situation—namely, that the vehicle is carrying a load that could affect its maneuverability or the space it occupies on the road.