Interpretation ID: nht93-4.1

DATE: May 18, 1993

FROM: John Womack -- Acting Chief Counsel, U.S. Department of Transportation, NHTSA

TO: George D. James, Jr. -- Safety Chairman, Unit 169 WBCCI

TITLE: None

ATTACHMT: Attached to letter dated 12-8-92 from George D. James, Jr. to Paul Jackson Rice (OCC 8094)

TEXT: This responds to your letter of December 8, 1992, to Paul Jackson Rice, former Chief Counsel of this agency, with respect to the Tekonsha electronic brake control. After having reviewed Mr. Rice's letter of December 4, 1992, you "still believe that using trailer brakes without activating the STOP LIGHTS is an unsafe procedure . . . ."

The purpose of the Tekonsha device is to control sway of the trailer by light application of the trailer brakes, and not to indicate that the trailer is slowing or stopping. Thus, activation of the trailer stop lamps when the Tekonsha device in use would be inappropriate. However, when the operator does intend to slow or stop, (s)he depresses the brake pedal (foot) which applies the brakes to both the trailer vehicle and the one that is towing it. At this point, the stop lamps are properly activated.

I hope that this explains the matter to you.