What is the required maximum height for mud flaps above the roadway?

The required maximum height for mud flaps above the roadway is 12 inches. This regulation is in place to ensure that mud flaps effectively serve their purpose, which is to minimize the spray from the tires of vehicles traveling on the road. When mud flaps are positioned too high above the roadway, they may not adequately control the dispersion of mud, water, or debris, which can lead to reduced visibility for other drivers and increased hazards on the road.

The 12-inch standard strikes a balance between functionality and safety, allowing for sufficient coverage without allowing the flaps to drag or become ineffective due to the vehicle's height or load. This specification is part of maintaining compliant vehicle standards to promote safety and mitigate road hazards.