Interpretation ID: aiam1750
House of Representatives
Washington
DC 20515;
Dear Mr. Anderson: This responds to your request for consideration of Mr. George H Dobson's December 27, 1974, request for reconsideration of Standard No. 121, *Air brake systems*, because of its costs.; Standard No. 121 requires that newly-manufactured air-braked vehicle stop from speeds of up to 60 mph on wet and dry surfaces in the loaded and unloaded condition, without leaving a 12-foot-wide lane and without lockup of wheels above 10 mph. These performance requirements are based on a safety need for improved braking performance on air brake- equipped highway vehicles. Controlled stopping within the traffic lane is particularly important to tractor-trailer combinations to avoid 'jackknife' skids. The incompatibility of vehicle sizes can be reduced significantly by establishing equal stopping distances for trucks and passenger cars.; We have analyzed the costs and benefits to be gained in upgradin truck, bus, and trailer braking performance and have concluded that the savings in lives, injury, and property damage justify the incremental costs of this standard. Standard 121 does not require retrofit of vehicles manufactured prior to the standard's effective date.; From a cost standpoint, it is noteworthy that the arguments fo increased weight limits for commercial vehicles relied, in part, on the increased braking performance of vehicles which meet Standard No. 121. A major reason for the heavier vehicles would be to reduce the costs of transportation, and Standard No. 121 contributes directly to that goal.; As you may be aware, the NHTSA has in fact proposed postponement of th standard due to the current economic situation. Based on several hundred comments, there was persuasive evidence that a delay at this late date would create far greater dislocation in the automotive industry than would a January 1, 1975, implementation. A copy of our decision not to postpone the standard is enclosed.; Yours truly, Richard B. Dyson, Acting Chief Counsel