On which vehicles are mud flaps always required?

Mud flaps are specifically mandated for dual wheel pickups because of the unique design and operational characteristics of these vehicles. Dual wheel pickups, often referred to as duallys, have two wheels on each side of the rear axle. This configuration can cause increased spray and debris to be projected onto the road and surrounding vehicles during operation. Therefore, mud flaps are essential in helping to mitigate this issue by reducing the amount of water, mud, and other road debris that may be thrown into the air, which enhances visibility and safety for other drivers.

While other vehicle types, such as passenger cars, sport utility vehicles, and light trucks, may benefit from mud flaps to some extent, the regulations particularly emphasize the requirements for dual wheel pickups due to their greater potential for creating hazardous conditions on the road from the additional tire surface area.