Michigan Truck Mud Flap Law

What Michigan makes you run

Michigan writes a performance rule, not a clearance number. Your truck, tractor, trailer, or combination must be built or equipped so the rear wheels don't throw water or road grit at a tangent steeper than 22.5 degrees off the road surface (MCL 480.25). Flap devices can't carry lamps or reflectors or stick out past the vehicle's width. Violation is a state civil infraction, up to $250. Roadside, an officer looks for a guard that blocks the spray.

Coverage and clearance

• Required: Yes
• Coverage: No stated tread-width number. A flap-type device may not extend beyond the vehicle's maximum width and can't carry any lamp, breakable reflective material, or reflecting buttons.
• Ground clearance: No fixed inch figure. Angle/performance rule: the rear wheels must not throw water or road-surface substances at a tangent steeper than 22.5 degrees measured from the road surface.
• Fine: State civil infraction under the Motor Carrier Safety Act, up to $250 per violation (MCL 480.25, penalty under MCL 480.17; Act 181 of 1963).

More for Michigan