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

The requirement for trailers that are 80 inches or more in width to have two red clearance lamps on the rear is grounded in safety regulations aimed at enhancing visibility and ensuring that other road users can clearly identify the dimensions of such wider vehicles. The red clearance lamps serve to delineate the outline of the trailer, especially at night or during low-light conditions, providing a critical visual reference point.

In contrast, side markers, tail lamps, or reflectors serve different purposes or are applicable under different conditions. For instance, amber side markers assist in identifying the width when viewed from the sides, while tail lamps are primarily used for signaling when the vehicle is stopping or moving. Green reflectors are generally not standard for trailers and do not meet the specified guidelines for width identification. The regulations are designed to improve overall road safety, hence the emphasis on red clearance lamps for wider trailers.