Interpretation ID: aiam2411
Manager of Engineering Services
Truck Body and Equipment Association
Inc.
5530 Wisconsin Avenue
Suite 1220
Washington
DC 20015;
Dear Mr. Crampton: This responds to the Truck Body and Equipment Association's letter o September 14, 1976, inquiring as to the effect of Standard No. 121, *Air Brake Systems*, on State laws relating to air brake performance. You ask whether the Commonwealth of Massachusetts can impose requirements pertaining to parking brake release on trucks and buses which differ from provisions contained in the Federal standard.; I believe that the question you raised is identical to a questio raised by the State of California, International Harvester Company, and White Motor Corporation in October 1974, prior to the effective dates of Standard No. 121. It was our opinion at that time that promulgation by a State of a more restrictive parking brake requirement providing for the installation of a release not specified in Standard No. 121 was prohibited by S 103(d) of the National Traffic and Motor Vehicle Safety Act. A copy of that letter is enclosed for your information.; Sincerely, Frank A. Berndt, Acting Chief Counsel