What must a trailer have in terms of side marker lamps if it is wider than 80 inches?

A trailer that is wider than 80 inches is required to have two amber side marker lamps. This requirement is in place to enhance visibility and safety on the road by clearly indicating the width of the trailer to other drivers. Amber lamps are specifically chosen for their visibility, especially in low-light conditions, as they signal caution.

Having two lamps allows for more effective visibility from both sides of the trailer, ensuring that other vehicles can see it from a greater distance. This contributes to preventing accidents and improving safety on highways, where larger vehicles can often pose additional challenges.

The other options do not comply with the regulations set forth for trailers. Red lamps are typically used for the rear of vehicles to indicate stop or tail lights, while clearance lamps serve a different purpose of indicating the overall height of the vehicle rather than its width. Therefore, the requirement for two amber side marker lamps is essential for compliance and safety on the road for trailers exceeding 80 inches in width.