Interpretation ID: 8816
Chief Engineer
Barrett Trailers, Inc.
P.O. Box 890670
Oklahoma City, OK 73189-0670
Dear Mr. McBay:
We have received your letter of June 13, 1993, asking that this Office review the two drawings you enclosed "for compliance with the upcoming conspicuity requirement", and "ask that our installation have your approval."
Under the National Traffic and Motor Vehicle Safety Act the manufacturer has the responsibility of determining whether its product conforms and then certifies its compliance with all applicable Federal motor vehicle safety standards. The Act does not provide authority for the agency to "approve" or "disapprove" any specific solution to methods of conformance. For this reason, we are unable to advise you in the manner you seek.
However, the agency does provide interpretations when specific questions are asked with respect to the requirements of the standard, and we are pleased to respond accordingly to your inquiries. You have raised four issues for our comment.
1. You have called to our attention that the "outside post" design of the trailers is configured so that the spacing of the posts along the length of the trailers is not the same. The retroreflective material will be evenly spaced in most areas, but breaks between material vary. You have asked whether this will "suffice for evenly distributed."
Under S5.7.1.4.2(a) of Federal Motor Vehicle Safety Standard No. 108, retroreflective sheeting applied to each side of a trailer need not be continuous "as long as not less than half of the length of the trailer is covered and the spaces are distributed as evenly as practicable." As we have advised many times, under Standard No. 108 the determination of practicability is to be made by the manufacturer in fulfillment of its obligation to certify that its product conforms to all applicable Federal motor vehicle safety standards. NHTSA believes that, as a general rule, a manufacturer is in the best position to determine what is practicable for its particular design. However, if that determination appears erroneous on its face, NHTSA will question it. Were you to manufacture trailers with the side conspicuity treatment spacings depicted on your drawings, NHTSA would not question your determination of practicability.
2. You have asked "if an area exists where a minimum 12" strip will not fit, can we install smaller material or must this area stay blank?"
As noted above, under S5.7.1.4.2, a strip of retroreflective material need not be continuous "as long as not less than half of the length of the trailer is covered." Therefore, if exclusion of the area in question would not result in less than half of the length of the trailer being covered, the area may be left blank.
If additional sheeting is required for a trailer to meet the length requirement, or if a manufacturer simply wishes to add it, it need not be "a minimum 12" strip." S5.7.1.3(d) of Standard No. 108 specifies that each segment of retroreflective sheeting shall have a length of 300 mm (i.e., 12 inches) +/- 150 mm. Therefore, a segment of sheeting as short in length as 150 mm (6 inches) could be applied to the area in question in compliance with the standard. An even shorter segment is permitted if necessary "to clear obstructions" if that should be the reason in your instance where a strip of 300 mm will not fit.
If the length of the area in question is smaller than 150 mm and its coverage is required for the conspicuity treatment on the trailer to meet the length requirement, then any length of material is acceptable.
3. You have asked us to note that the white strips in the upper rear corners do not meet. You have asked "Must white be touching or can there be a gap between the strips?"
Figure 30 "Typical Trailer Conspicuity Treatments" depicts two configurations in which the white strips of retroreflective material intersect at right angles in the upper rear corners. The requirement that Figure 30 illustrates is set forth in S5.7.1.4.1(b), which specifies, in pertinent part, "two pairs of white strips of sheeting, each pair . . . applied horizontally and vertically to the right and left upper contours of the body . . . as close to the top of the trailer and as far apart as practicable." There is no explicit requirement in this paragraph that the horizontal and vertical strips intersect or touch. There is an implicit requirement in the specification that the strips be "as close to the top and as far apart as practicable", but the requirement is subject to the manufacturer's determination of practicability. In other words, if the manufacturer's determination of practicability results in a gap between the strips, NHTSA will not question this determination unless it appears clearly erroneous.
4. You represent that your design makes it impossible "to make a nice continuous square corner", and that "[i]nstallation of the white corners is also closer than 3" from red top rail lights." You ask whether there is "any tolerance on the 3" dimensions?
There is no tolerance on this requirement. S5.7.1.4(b) states that "The edge of white sheeting shall not be located closer than 75 mm to the edge of the luminous lens area of any lamp that is required by this standard." The diagrams you enclose depict the horizontal white strip directly below the clearance lamps, which are required by Standard No. 108, so that each design does not accord with Standard No. 108.
We have some comments on each design. On "Model 80MP6-DD" it appears to us that, under a determination of practicability, the white strips could be lowered until the required minimum spacing between it and the clearance lamp was achieved. There is no prohibition against placing the material on the roll-up door.
The trailer identified as "GNXS-207" raises a more difficult problem because there appears to be no place where the strips could be relocated. Consideration must be given, therefore, to relocation of the clearance lamps. Under Table II of Standard No. 108, clearance lamps are intended to "indicate the overall width of the trailer". Although clearance lamps should be "as near the top . . . as practicable", they need not be "[w]hen the rear identification lamps are mounted at the extreme height of a vehicle" (S5.3.1.4). The rear identification lamps on GNXS-207 are mounted at the extreme height of the vehicle. The clearance lamps could be relocated to the fender where the stop, turn, and taillamps are presently installed. In that location, the clearance lamps would also be better able to fulfill the intent that they indicate the overall width of the trailer, which appears to occur at the fender rather than at the upper part of the body.
We hope that these interpretations are helpful.
Sincerely,
John Womack Acting Chief Counsel
ref:108 d:7/14/93