Every truck with a gross weight exceeding 11,000 pounds, trailer and truck tractor (without a semitrailer) driven on a highway shall be so constructed or equipped as to bar water or other road surface substances thrown from the rear wheels of such vehicle or combination at tangents exceeding 22 1/2 degrees, measured from the road surface, from passing in a straight line to the rear of such vehicle or combination. (Dec. 9, 2002, P.L.1278, No.152, eff. 60 days)
Pennsylvania Legal Code