[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR393.24]

[Page 397]
 
                        TITLE 49--TRANSPORTATION
 
                      DEPARTMENT OF TRANSPORTATION
 
PART 393_PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of 
Contents
 
       Subpart B_Lamps, Reflective Devices, and Electrical Wiring
 
Sec.  393.24  Requirements for head lamps, auxiliary driving lamps and 
front fog lamps.

    (a) Headlamps. Every bus, truck and truck tractor shall be equipped 
with headlamps as required by Sec.  393.11(a). The headlamps shall 
provide an upper and lower beam distribution of light, selectable at the 
driver's will and be steady-burning. The headlamps shall be marked in 
accordance with FMVSS No. 108. Auxiliary driving lamps and/or front fog 
lamps may not be used to satisfy the requirements of this paragraph.
    (b) Auxiliary driving lamps and front fog lamps. Commercial motor 
vehicles may be equipped with auxiliary driving lamps and/or front fog 
lamps for use in conjunction with, but not in lieu of the required 
headlamps. Auxiliary driving lamps shall meet SAE Standard J581 
Auxiliary Upper Beam Lamps, July 2004, and front fog lamps shall meet 
SAE Standard J583 Front Fog Lamp, August 2004. (See Sec.  393.7 for 
information on the incorporation by reference and availability of these 
documents.)
    (c) Mounting. Headlamps shall be mounted and aimable in accordance 
with FMVSS No. 108. Auxiliary driving lamps and front fog lamps shall be 
mounted so that the beams are aimable and the mounting shall prevent the 
aim of the lighting device from being disturbed while the vehicle is 
operating on public roads.
    (d) Aiming. Headlamps, auxiliary driving lamps and front fog lamps 
shall be aimed to meet the aiming specifications in FMVSS No. 108 (49 
CFR 571.108), SAE J581, and SAE J583, respectively.

[70 FR 48046, Aug. 15, 2005]