A plow blade has a moldboard shaped with a concave front contact surface that faces a forward direction and has a convex rear frame surface that faces an opposite rearward direction, wherein the rear frame surface has a supporting frame with one or more supporting frame members that extend in the rearward direction. A first indicating lamp is coupled to the plow blade and is energizable to emit light of a first color in the rearward direction, wherein the energized first indicating lamp is concealed from visibility from the forward direction. A second indicating lamp is coupled to the plow blade, energizable to emit light of a second color, and visible from the forward direction.