Skip to main content
Search Interpretations

Interpretation ID: nht75-3.38

DATE: 11/24/75

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Hon. J. P. Murtha - H.O.R.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your November 5, 1975, request for the criteria necessary for construction of testing equipment used to demonstrate compliance with Standard No. 121, Air Brake Systems.

The motor vehicle safety standards, including Standard No. 121, are established as requirements that vehicles must be capable of meeting if tested by the National Highway Traffic Safety Administration (NHTSA). However, the standards are not developed as demonstration procedures that detail methods a manufacturer would use to establish that its products comply. The development of actual test protocols to determine that products conform to the requirements is the responsibility of the regulated industry and the associated industries that service them.

Thus the Thiele Corporation, as a manufacturer of air-braked vehicles, may choose whatever test method gives it an adequate basis for certification that its products comply (15 U.S.C. @ 1397 (a)). Test equipment has been developed by several commercial sources, and Thiele can choose proper systems by consulting with the manufacturers of the brake components it uses. As for specifications for a test track, actual road tests are not necessary to establish compliance with Standard No. 121 where other reasonable means, such as engineering calculations coupled with laboratory tests, can be used to the same effect. Supplier warranties and instructions are one of the primary means by which smaller assemblers ascertain that their products conform.

Sincerely,

ATTACH.

CONGRESS OF THE UNITED STATES

House of Representatives

November 5, 1975

Richard B. Dyson, Chief Counsel -- National Highway Traffic Safety Administration

Dear Mr. Dyson:

Mr. William Wells of Thiele, Inc., a private truck building company, has requested that I inquire about the requirements for testing equipment under the Motor Vehicle Safety Standard 121 that went into effect in March of 1975.

Mr. Wells is interested in testing his own vehicles rather than bringing them to a professional testing track. Will you please inform me, in writing, what the criteria are for a company to build its own testing equipment in order to conform with the safety standards.

Thank you for your assistance in this matter.

Sincerely,

JOHN P. MURTHA -- Member of Congress