Interpretation ID: aiam1671
President
Bertolini Engineering Co.
Inc.
P.O. Box 338
Montgomeryville
PA 18936;
Dear Mr. Bertolini: This responds to your October 17, 1974, letter to President Ford askin that the Federal government consider a delay of the effective date for Standard No. 121, *Air brake systems*, because of its cost to vehicle manufacturers and to their customers.; 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.; 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.; The standard only applies to new vehicles because our statutor authority to regulate motor vehicle safety does not extend to used vehicles (15 U.S.C S 1397(b)(1)).; As for a differential in performance between heavy and lighte vehicles, we already have issued a Standard No. 108-75 *Hydraulic brake systems*, which mandates comparable stopping performance for hydraulic-braked vehicles, effective September 1, 1975.; From a cost standpoint, it is noteworthy that proponents of increase size and weight limits for commercial vehicles rely, in part, on the increased braking performance of vehicles which meet Standard No. 121. A major reason for the larger vehicles would be to reduce the costs of transportation, and Standard No. 121 contributes directly to that goal.; Standard No. 121 has already been delayed for two years and we do no have plans to further delay the standard, for the reasons stated above.; Yours truly, Richard B. Dyson, Acting Chief Counsel