Interpretation ID: aiam1479
Superior Trailer Works
1430 East Washington Boulevard
Los Angeles
CA 90021;
Dear Mr. Richards: This responds to your April 22, 1974, question concerning th certification responsibility of a small manufacturer of trailers that must conform to Standard No. 121, *Air brake systems*. You ask if road testing of any or all vehicles produced would be necessary to satisfy the requirements.; A manufacturer must 'exercise due care' in certifying that the vehicle manufactured by him comply with the applicable standards (National Traffic and Motor Vehicle Safety Act of 1966, S 108(b)(2), 15 U.S.C. S 1392(b)(2)). What constitutes due care in a particular case depends on all relevant facts, including such things as the time to elapse before a new effective date, the availability of test equipment to small manufacturers, the limitations of current technology, and above all the diligence evidenced by the manufacturer.; A small manufacturer of standard and custom trailers might fulfill hi due care responsibility to assure that each of his trailers is capable of meeting the standard in several ways. For example, he could establish categories of models which share a common brake and axle system and certify them all on the basis of tests on the most adverse configuration in the category. Calculations should be written down in such a case to establish that reasonable care was taken in these decisions.; Alternatively, joint testing might be undertaken with a trad association or with a major supplier of brake and axle components. In the case of standard models, you might be able to rely on the supplier's warranty of his products' capacities.; Neither of these methods would require road testing of each vehicl manufactured, nor would every model have to be road tested. A manufacturer must simply satisfy himself that the trailer is capable of meeting the stopping performance requirements if it were tested by the NHTSA.; Yours truly, Richard B. Dyson, Assistant Chief Counsel