Abstract: The separate reflector and light bulb components presently used in flashing-light signal apparatus employed at railway crossings are replaced by a sealed-beam type incandescent reflector lamp having a window-aperture in the concave reflector portion of the lamp envelope which is adapted to be aligned with a side opening in the lamp-housing of the signaling apparatus and thus permits the operation of the light source inside the sealed-beam lamp to be checked visually by the engineer of an approaching train. Additional cost and functional advantages are obtained by also making the separate red-colored lens component of the signal apparatus an integral part of the sealed-beam warning lamp and by using a long-life halogen-cycle type lamp component as the light source within the sealed-beam reflector envelope.