Interpretation ID: aiam1824
Chairman
Committee on interstate and Foreign Commerce
House of Representatives
Washington
DC 20515;
Dear Mr. Chairman: Thank you for your February 19, 1975, request for our evaluation o Representative B. F. Sisk's concern that the National Highway Traffic Safety Administration (NHTSA) has incorrectly interpreted the definition of 'Motor vehicle' as it appears in S 102 of the National Traffic and Motor Vehicle Safety Act of 1966:; >>>Sec. 102. As used in this title -- (3) 'Motor vehicle' means any vehicle driven or drawn by mechanica power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.<<<; Mr. Sisk questions whether air-braked trailers which transport far commodities from the field to processing plants or warehouses qualify as motor vehicles under this definition. You also ask for the status of a request for exemption from Standard No. 121, *Air brake systems*, which concerns these vehicles.; The NHTSA has developed criteria for the interpretation of th definition of motor vehicle in the area of heavy vehicles with an off-road function. We conclude that the definition includes vehicles which use the highway on a necessary and recurring basis to move between work sites. We have cited mobile cranes, drill rigs, and towed equipments such as brush chippers and pull-type street sweepers as examples of this motor vehicle class. Following the rationale of necessary and recurring road use, we have excluded from the definition such farm vehicles as mobile feed mixers used strictly in feedlot operations. We believe, however, that the trailers in question have a primary function of highway transportation of bulk produce form the field to the plant.; The Act does not provide a specific exemption for vehicles used i agricultural pursuits. The only reference in the Act to agricultural vehicles is a provision in Title III (as it appeared in 1966) that authorized 'research, development, and testing relating to the safety of machinery used on highways or in connection with the maintenance of highways (with particular emphasis on tractor safety' (S 301). We have interpreted this provision to express Congress' intent that specialized machines which have a strictly non-transportation function (e.g., paving machines, road graders, farm combines, and farm tractors in particular) are not motor vehicles.; With regard to exemption for the trailers in question, we have on request outstanding to exempt these trailers from the parking brake requirements of the standard, because current designs in response to our requirements conflict with the use of these vehicles. We agree that a design that requires parking brake application upon disconnection of the air supply can interfere with storage and marshalling of these vehicles if brake release is not assured after long periods of disconnection. Because of this specific problem in agricultural pursuits, we have decided to undertake rulemaking to exempt these vehicles from that requirement for a year in order to permit manufacturers to modify their designs to solve the problem. We expect to issue a proposal shortly.; I hope that I have been responsive to your questions, and I welcom further opportunity to clarify our interpretations of the National Traffic and Motor Vehicle Safety Act of 1966.; Sincerely, James B. Gregory, Administrator