Interpretation ID: nht93-7.17

DATE: October 8, 1993

FROM: Thomas D. Price -- President, Strait-Stop Manufacturing Co., Inc.

TO: Marvin Shaw -- Chief Counsel, NHTSA

COPYEE: Senator Boren; Senator Nickles; Representative Bill Brewster

TITLE: Re: Docket N. 93-69; Notice 1 and Docket No. 92-29; Notice 2

ATTACHMT: Attached to letter dated 1/3/94 from John Womack (signed by Kenneth Weinstein) to Thomas D. Price (A42; Std. 121)

TEXT:

I am hereby requesting immediate definition of specific technical terminology used in the Notice of Proposed Rule Making (NPRM) issued in FR/Vol. 58, No. 186/Tuesday, September 28, 1993. You indicated on the telephone, this week, you could not give assurance of a timely response to any questions for terminology definition. However in view of the scope and significance of the proposed standards, it seems mandatory, and in the best interest of all affected parties, that all commenters have a common basis of knowledge as to the intended meaning of specific technical terms, upon which they can base their responses required on or before November 29, 1993.

I questioned three professors of mechanical/electrical engineering at the University of Oklahoma as to the meaning of the terminology listed below and was unable to receive a comfortable commonality of definition. This would indicate that the listed terminology may have some specific meaning for the Agency that is not readily discernible by engineers who lack the prior association with the persons or entities which have developed specific understanding regarding definition.

1. On pages 50757 and 50760 of the reference documents, there are proposed amended definitions to S571.105, S4 and S571.121, S4 which delete the definition of "antilock system", and add the definition "antilock braking system". In the latter definition, in sub-paragraphs (1) and (2) the terminology "rate of angular rotation of wheels" and "rate of wheel angular rotation" are used, but lack definition. Please define this terminology.

2. There is a definite ambiguity as to the precise meaning of the term "performance". In some places it is obviously talking about the vehicle's ability to meet the standards of "stopping distance" and "lateral stability". However, in other places it is, just as obviously, referring to a step by step functional pattern designed to achieve the prior "performance" criteria, the achievement of which becomes a verification that the prescribed functional pattern is effective. Please define the terminology "performance" as it applies to the GOAL of the Agency to be accomplished by the proposed rules.

We urgently and respectfully request that the Agency provide the two definition clarifications specified above by November 8, 1993, which is one month from the date hereof.