Interpretation ID: nht88-3.40

TYPE: INTERPRETATION-NHTSA

DATE: 09/10/88

FROM: LARRY P. EGLEY

TITLE: REQUEST FOR EVALUATION/INTERPRETATION OF PROPOSED INVENTION: "SUDDEN STOP FLASHER (SSF)"

ATTACHMT: ATTACHED TO LETTER DATED 08/09/89 FROM STEPHEN P. WOOD -- NHTSA TO LARRY P. EGLEY; REDBOOK A33 [2]; STANDARD 108; LETTER DATED 01/17/89 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 3028; LETTER DATED 05/23/89 FROM LARRY P. EGLEY TO KAT HLEEN DEMETER -- NHTSA; LETTER DATED 09/10/88 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 2530; REPORT DATED 09/07/88 FROM LARRY P. EGLEY, AN APPEAL FOR VARIANT INTERPRETATION OF NHTSA STANDARDS AS THEY RELATE TO BRAKE LIGHTS AND THE SUDDEN STO P FLASHER [SSF]; LETTER DATED 07/13/88 FROM KATHLEEN DEMETER -- NHTSA TO LARRY P. EGLEY; LETTER DATED 06/23/88 FROM LARRY P. EGLEY TO RALPH HITCHCOCK -- NHTSA; OCC 2256; LETTER DATED 06/20/88 FROM LEWIS S. BUCHANAN -- EPA TO LARRY P. EGLEY; OCC 2199; LET TER DATED 06/09/88 FROM LARRY P. EGLEY TO LEWIS BUCHANAN

TEXT: The Sudden Stop Flasher (SSF) would work in conjunction with standard automobile brake lights. During routine decelerations, the brake lights would function normally. However, at unusual or "unexpectedly" high deceleration rates, such as when a driver suddenly sees a dog on the road or an accident ahead, the SSF would utilize a pendulum-type accelerometer in conjunction with a special high-speed flasher to rapidly flash the brake lights automatically (such as drivers sometime attempt to do themselves to warn the driver behind but only when they have time).

To make the effective flash rate even higher, the high-mount light would flash in rapid sequence with the two lower brake lights, the two lower lights flashing simultaneously.

I believe this concept would be especially effective in preventing high-speed crashes such as on Interstate highways when separation intervals are greater and when rapid deceleration may be completely unexpected. These crashes too frequently result i n ruptured gas tanks and fatalities.

The SSF would be especially applicable, I believe, to automobiles equipped with anti-skid brakes. Ironically, cars with anti-skid brakes may become involved in accidents because of their superior braking performance when the car behind them crashes i nto them because the car behind is not equipped with anti-skid brakes and therefore cannot match the braking performance. The SSF could provide the extra 2-or 3- second warning which could be the difference between a controlled stop and a disastrous cra sh.

A special feature would be the "Crash Lock-Up Mode." This feature would cause the system to "lock-up" in the rapid warning flash sequence mode whenever an "impact-level" (i.e., an actual crash) is encountered. When drivers have an accident, they are often confused and disoriented and consequently fail to take measures to warn other drivers - such as turn on the hazard warning flashers. The Crash Lock-Up feature would automatically send out a continuous warning when an actual crash occurs, thus possi bly preventing yet another crash. The Crash Lock-Up would remain actuated until the ignition switch is recycled. This feature would be especially helpful if a crash occurred on a foggy night or when the visibility is otherwise poor.

The actual point or g-level at which the SSF would actuate would be determined by testing and the units would be preset and sealed at the factory. I do not believe any compensation would be necessary for up-grades or down-grades. The system would act uate somewhat later on an upgrade and somewhat earlier on a downgrade, which would be inherently appropriate. Likewise, I do not believe any compensation would be necessary for the size of the automobile because the deceleration level would be the criti cal factor, regardless of the size or weight of the automobile.