Interpretation ID: aiam1829
House of Representatives
Washington
DC 20515;
Dear Mr. Andrews: This responds to your February 18, 1975, request for information i behalf of a constituent, concerning any Federal regulation which might require bulk oil trucks to have a 120-inch wheelbase and be equipped with certain wheels, tires, and axles.; Neither the National Highway Traffic Safety Administration (NHTSA) no the Bureau of Motor Carrier Safety of the Federal Highway Administration has issued a safety standard which requires a certain wheelbase or the components listed by your constituent.; NHTSA has issued Standard No. 121, *Air brake systems*, whic establishes minimum performance requirements for air-braked vehicles. A major requirement is that an air-braked vehicle must be capable of stopping within a distance that is comparable to average passenger car performance. This requirement is intended to reduce the incompatibility in braking performance between heavy trucks and passenger cars which must share the nation's highways.; Manufacturers are free to choose any design which permits thei vehicles to stop in the required distance. It is possible that the manufacturer of your constituent's vehicle has found that a longer wheelbase and stronger axles, brakes, wheels, and tires are necessary to insure that the vehicle is capable of consistently stopping without loss of control in a distance comparable to the average passenger car. We consider the modification of vehicles in this fashion to be a significant contribution to motor vehicle safety.; Sincerely, James C. Schultz, Chief Counsel