Interpretation ID: aiam3825
Esq.
Arent
Fox
Kintner
Plotkin & Kahn
1050 Connecticut Avenue
N.W.
Washington
DC 20036-5339;
Dear Mr. Henneberger: This is in reply to your letter of September 26, 1983, asking for a interpretation on behalf of your client, Jacobs Manufacturing Company.; You referenced an interpretation of August 31, 1978, which we gave you also on behalf of Jacobs. Your client manufactures a diesel engine retarder system which would be provided a means to warn following drivers when the system was in use. The specific means of warning discussed in the 1978 letter was to connect the retarder activation switch to the hazard warning system, either as original or aftermarket equipment. We concluded that his installation augmented the hazard warning system, and thus did not impair the hazard warning system within the prohibition of paragraph S4.1.3 of Standard No. 108. We also concluded that it would not render inoperative the hazard warning system, and thus was not a violation of the 'anti-tampering' provision of Section 108(a)(2)(A) of the Traffic Safety Act.; Apparently, a customer of Jacobs has asked it to wire its warnin system through the stop lamps. A separate manually-operated switch will be provided. We understand that when the warning system is operational there is no difference of light intensities when the brakes are applied. You have asked us for a re-interpretation, on the basis of these new facts, that the changes retarder warning will not violate either paragraph S4.1.3 or section 108(a)(2)(A). You believe that the warning system is still permissible, because the stop lamps when so used will nevertheless indicate that the vehicle is diminishing its speed by braking, and because of interpretations by this office that retarder controls can be incorporated with the foundation brake controls and activated with the foundation brakes.; We have reviewed the 1978 interpretation allowing use of the retarde system through the hazard warning system, and the two 1974 interpretations with reference to incorporation of supplementary braking devices with foundation controls. We agree with your interpretation that the latter interpretations impliedly require activation of the stop lamps when the supplementary braking devices are used. The agency is not prepared at this time to modify either interpretation, and you may inform your client that there is no Federal legal prohibition against its wiring the retarder to activate the stop lamps when it is in use.; However, we wish to point out an area of potential risk which you client should weigh before proceeding to offer this option and which, if it occurred, could be viewed as an impairment of the stop signal within the prohibition of S4.1.3. Under the Jacobs plan, activation of the stop lamp when the retarder is engaged would indicate only a lessened rate of speed. Because there is no difference in intensity, a following driver would have no indication when the brake was applied to signal a normal or sudden stop, such as might be required when a child or animal runs into the roadway.; If you have any further questions, we shall be happy to answer them. Sincerely, Frank Berndt, Chief Counsel