How many side marker lamps must a trailer with a gross weight over 3,000 pounds have?

A trailer with a gross weight over 3,000 pounds is required to have two side marker lamps on each side. This regulation is in place to ensure the visibility and safety of the trailer when on the road, particularly in low-light conditions. The presence of these lamps aids other drivers in identifying the width and presence of the trailer, enhancing safety during nighttime or poor visibility situations.

The requirement for two lamps on each side allows for adequate illumination and helps ensure that the trailer is visible from various angles by other road users. This is an important aspect of vehicle standards to help prevent accidents and ensure that larger vehicles like trailers are noticeable on the roadway.