Interpretation ID: 86-4.32

TYPE: INTERPRETATION-NHTSA

DATE: 08/01/86

FROM: DAVID M. CIMA

TO: LEGAL COUNSEL -- NATIONAL HIGHWAY TRANSPORTATION SAFETY ADMINISTRATION UNITED STATES DEPARTMENT OF TRANSPORTATION

TITLE: VISIBLE DISPLAY TO AUTOMOBILE DRIVER OF STATUS OF TRANSMISSION(PARK, REVERSE, NEUTRAL, DRIVE, LOW . . . ALSO KNOWN AS "PRNDL INDICATOR" IN THE AUTO INDUSTRY)

ATTACHMT: ATTACHED TO LETTER DATED 08/30/86 EST, TO DAVID M.CIMA, FROM ERIKA Z. JONES, REDBOOK A29 (3) STANDARD 102

TEXT: Dear Sir:

I have been told that STANDARD for stipulates that when a driver gets behind the wheel the "setting" of the transmission at that time will be visibly evident before he puts the key into the ignition.

Normally, there is a mechanical linkage to a "needle" that gives the indication. But with newer technologies like light emitting diodes and liquid crystal displays, etc., that same indication can be given in the instrument cluster, perhaps even more clearly than with traditional approaches.

Some auto manufacturers are considering (or may already have done) putting a weight switch in the seat which would be activated when the driver sits down and turn on a lighted PRNDL display.

I, on the other hand, am working with another technology that would sense the driver's movement as he slid into the seat(by sensing his infrared radiation) and activate the display.

But, and this is the reason for my writing to you, using the type of infrared sensor that is on the market today, I would get only one electronic "blip" when the driver entered. Then the display would be activated with a simple timer that would keep it lit for some predetermined period, say 5 minutes. However, if the driver entered his car with his lunch and spent 20 minutes eating and then proceeded to insert key and drive away, the PRNDL indicator would have been off 15 minutes before the man started his car.

As an extreme case, someone goes to a drive-in movie and may be in the same spot for 2 hours before restarting their car.

In short, does the law say that the PRNDL indicator must be visible to the driver when he enters the car? Or must it be visible whenever anyone is behind the wheel? (Naturally, in the case of someone in the car with the engine idling, the indicator would be lit.)

If the regulation states that the indicator must be "visible" no matter what the situation or the duration of time the person is behind the wheel, I still may be able to make the infrared approach work--but it will be much more difficult.

As you well know, I would be foolish to work on or offer something that didn't meet the letter of the law--and no manufacturer would accept it anyways. Thus I would appreciate whatever clarification of the situation that you could give me.

I truly appreciate your efforts.

Sincerely,