Interpretation ID: aiam2083
Motor Vehicle Inspection
523 E. 12th Street
Des Moines
Iowa 50319;
Dear Mr. Schellhase: This responds to your May 29, 1975, letter to Mr. Vincent Esposito o the National Highway Traffic Safety Administration (NHTSA), in which you indicate your desire that a 'second independent means of stopping be made mandatory' on newly-manufactured motor vehicles.; Federal motor vehicle safety Standard No. 105-75 (49 CFR 571.105-75 becomes effective January 1, 1976, for passenger cars, and it establishes requirements for the service and parking brake systems of these vehicles (copy enclosed).The test procedures for parking brake testing specify that the service brake control be released in testing the parking brake system. This has the practical effect of requiring a separate parking brake similar to that specified by the Iowa law you cited in your letter.; Federal motor vehicle safety Standard No. 121, (49 CFR 571.121) becam effective January 1, 1975, for air-braked trailers and March 1, 1975 for air-braked trucks and buses (copy enclosed). It establishes requirements for the service and parking brake systems of these vehicles. Section S5.6.4 of the standard states that 'The parking brake control shall be separated from the service brake control.'; Section 103(d) of the National Traffic and Motor Vehicle Safety Act i 1966 (15 U.S.C. 1392(d)) provides that no State or political subdivision of a State may promulgate or continue in effect standards applicable to on aspect of motor vehicle or motor vehicle safety standard, unless the standards are identical.; As noted, STandard No. 105-75 and Standard No. 121 include requirement for the parking brake control aspect of braking performance. The Federal requirements must be regarded as conclusive with regard to this aspect of performance in order to maintain the uniformity necessary in a Federal regulation scheme. If States were permitted to impose additional requirements in an area regulated by a Federal safety standard manufacturers would be confronted with an impossible task of compliance. This reasoning formed the basis of a recent decision rendered in a case brought by the Motorcycle Industry Council, Inc. against the State of California in the United States District Court for the Eastern District of California concerning the preemption of a California State requirement that motorcycle headlamps be wired to operate when the engine is running. The Court held that the California requirement is preempted by the Federal Motor Vehicle Safety Standard No. 108 since the NHTSA intended to cover all aspects of performance directly involving motorcycle headlamps.; Therefore, requirements such as those described in your letter would b preempted by Standard No. 105-75 in the case of passenger cars, since the aspect of performance that would be affected is covers by the Federal standard. The same is true for motorcycles, covered by Standard No. 122, *Motorcycle Brake Systems*, and trucks, buses, and trailers equipped with air brake systems, covered by Standard No. 121.; With regard to trucks, buses, and multipurpose passenger vehicles tha are equipped with hydraulic brake systems, the NHTSA is in the process of developing a hydraulic brake standard. I have forwarded a copy of your letter to the NHTSA Office of Crash Avoidance for consideration in developing the standard in this area.; Sincerely, Frank A. Berndt, Acting Chief Counsel