[Code of Federal Regulations] [Title 49, Volume 5] [Revised as of October 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR393.9] [Page 369] TITLE 49--TRANSPORTATION CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 393_PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of Contents Subpart B_Lamps, Reflective Devices, and Electrical Wiring Sec. 393.9 Lamps operable, prohibition of obstructions of lamps and reflectors. (a) All lamps required by this subpart shall be capable of being operated at all times. This paragraph shall not be construed to require that any auxiliary or additional lamp be capable of operating at all times. (b) Lamps and reflective devices/material required by this subpart must not be obscured by the tailboard, or by any part of the load, or its covering by dirt, or other added vehicle or work equipment, or otherwise. Exception: The conspicuity treatments on the front end protection devices may be obscured by part of the load being transported. [70 FR 48027, Aug. 15, 2005]