Interpretation ID: aiam2573
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 February 8 1977, petition for rulemaking to amend the definition of 'unloaded vehicle weight' and to add a new definition to 49 CFR Part 571.3 for 'special purpose vehicle.' The National Highway Traffic Safety Administration (NHTSA) denies your requested rulemaking.; Your petition requests an amendment of the term 'unloaded vehicl weight' similar to that proposed by Chrysler's December 20, 1976, petition. Both petitions recommend that, for purposes of barrier crash testing of certain vehicles, the unloaded vehicle weight be the lesser of the weight of a completed comparable model vehicle from which the particular vehicle is derived or 5,500 pounds. Further, you request an additional definition of 'special purpose vehicle' that would distinguish vehicles designed for a specific work function from other vehicles produced from the same chassis. We have determined that the effect of creating such a vehicle category as special purpose vehicle in conjunction with the establishment of arbitrary weights for vehicles when undergoing compliance testing would, in some situations, undermine the effectiveness of the motor vehicle safety standards. Vehicles falling into the category could, according to your suggested scheme, be tested at a weight which differs from their actual weight as equipped.; In the case of Standard No. 301, *Fuel System Integrity*, such a resul would possibly violate Congress' order in the 1974 Amendments to the National Traffic and Motor Vehicle Safety Act (Pub. L. 93-492) that the NHTSA not diminish the level of safety established at that time in the standard.; To allow certain vehicles to be tested at a weight which differs fro their actual weight, would permit the operation of vehicles which, as equipped, could fail the requirements of the standard.; You should note that the agency intends to proceed with the rulemakin to amend the definition of 'unloaded vehicle weight' as recommended in a petition from Chrysler dated November 29, 1976. This amendment will incorporate changes in the definition previously made by the NHTSA through interpretation.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs;