Section 66-3-821 - Requirements for headlamps and auxiliary road-lighting lampsA. Headlamps and lamps or auxiliary road-lighting lamps shall be mounted so that the beams are readily adjustable, both vertically and horizontally, and the mounting shall be such that the aim is not readily disturbed by ordinary conditions of service. B. Every bus, truck or truck tractor shall be equipped with two single-beam headlamps supplemented by two auxiliary single-beam headlamps furnishing, respectively, an upper and lower distribution of light, also selectable at the driver's will. C. Headlamps shall be constructed and installed so as to comply with the provisions of Sections66-3-830 through 66-3-832 NMSA 1978. 1953 Comp., § 64-3-821, enacted by Laws 1978, ch. 35, § 127.