What is required on the side of every trailer that is 80 inches or more in width?

For trailers that are 80 inches or more in width, one red side marker lamp is a regulatory requirement. This lamp serves to increase visibility and safety on the road, particularly in low-light conditions or when viewed from the side. The presence of the red side marker lamp helps other drivers see the dimensions of the trailer and recognize its position, which is critical for avoiding accidents.

This requirement aligns with safety regulations aimed at ensuring that large vehicles like trailers are identifiable to other road users. Visibility is especially important for wider trailers because they may not be as easily seen compared to standard-width vehicles. Ultimately, the red side marker lamp contributes to safer driving conditions by reducing the likelihood of collisions due to visibility issues.