Interpretation ID: nht91-1.14

DATE: January 5, 1991

FROM: Chris Lawrence -- Chang & Lawrence

TO: August L. Burgett -- Safety Standards Engineer, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3-21-91 from Paul Jackson Rice to Chris Lawrence (A37; Std. 108; VSA 108(a)); Also attached to letter dated 8-17-89 from Stephen P. Wood to Alan S. Eldahr (VSA 108(a)(2)(A))

TEXT:

I got your name from Mr. Patrick Maguire, Director of the Minnesota Trade Office in Taiwan. He said you might be able to answer questions I have concerning safety regulations for automobiles in the United States.

I am considering producing a new product, an electronic sign board for cars, that would display messages on the outside of the vehicle. The driver would select one of several pre-programmed messages by voice command; a voice recognition unit on the sign board would interpret the command and initiate display of the appropriate pre-programmed message. A voice output unit would confirm that the right message was selected by announcing the fact on a voice output unit.

My questions concern safety regulations that would restrict the use of lights to form messages on the outside of cars or from a window. The "Federal Register" (Standard 108 of Part 571 of Chapter 49) explains what lamps are specifically required on motor vehicles, and states that additional lamps that impair the effectiveness of the required lamps are prohibited. What is meant by "impairing the effectiveness of the required lamps"? And are there restrictions about what can be mounted in a window of a vehicle? Your assistance is greatly appreciated.