Visionary Lighting Systems
1409 Sweetgum Circle
Keller, TX 76248
Dear Mr. Tubbs:
Thank you for providing a FAX copy of your letter of April 27, 1995, to Philip Recht. As Taylor Vinson explained to you when you phoned, the agency had no record of receiving your original letter.
Our letter of April 13, 1995, to you was based upon your representation that the strip lights in your system would be "Aviation Green". We advised you that use of this color has the potential to create a measure of confusion rather than caution, thereby affecting the effectiveness of the mandatory side lighting equipment, i.e., amber front side markers, red rear side markers, and red and white conspicuity striping or red reflectors.
You have asked whether our response would be different if the strip lamps were red or amber in color, as shown in the drawings of a van trailer in your Attachment A. In this scheme, amber lamps would be located on the side of the trailer, and red lamps on the rear. Because these colors are associated with caution, we do not believe that they would impair the effectiveness of any of a trailer's required lighting equipment.
You expressed your understanding that, if the three rear identification lamps are installed at the top of a trailer, the clearance lamps can be mounted at the bottom and vice versa, as reflected in the drawings shown in your Attachment C. This is not exactly correct. Table II of Standard No. 108 requires identification lamps, without exception, to be mounted "as close as practicable to the top of the vehicle." While clearance lamps also are required to be "as near the top as practicable" (Table II), when the rear identification lamps are mounted at the extreme height of the vehicle the rear clearance lamps need not be located as close as practicable to the top of the vehicle (paragraph S18.104.22.168). This configuration is reflected in the drawing on Attachment C titled "Identification Lights on Top". The drawing "Identification Lights on Bottom" does not depict a location for identification lamps that conforms to Table II.
Because clearance lamps are intended to indicate the overall width of the vehicle, the exception originated to accommodate trailer designs in which the widest part of the trailer was the fenders. In the van configuration shown on Attachment C, it would be practicable for both identification and clearance lamps to be mounted at the top of the trailer, and that is the location preferred by this agency for clearance lamps, notwithstanding S22.214.171.124.
If there are other questions you have, Taylor Vinson will be happy to answer them for you.
John Womack Acting Chief Counsel ref:108 d:6/9/95