Interpretation ID: 2399y
3772 Prairie Street
Grandville, MI 49418
Dear Mr. Stoel:
This is in reply to your letter to John Womack of this Office, suggesting that the color of taillamps on motor vehicles be green.
The agency is concerned about methods to effectively improve rear lighting and signaling. The issues involved include lamp size, location, operation, combinations and separation, and color. We are learning that changes in lamp function, operation, and color should be approached in a conservative fashion, so as not to confuse the operators of other vehicles.
With specific respect to use of the color green on rear lighting equipment, we are aware that some research suggests a green/red color scheme may enhance driver performance. In such systems, a green lamp indicates that the accelerator pedal is applied, amber that the foot has been lifted from the accelerator pedal, and red, that the brake is being applied. Some years ago, an experiment was conducted with such a system using transit buses in the D.C. area. The results were inconclusive. Although some research suggests a possible improvement in driver performance with green/red lamps, there are no data addressing the possible driver confusion that might arise from multiple color lighting arrays.
Thank you for your suggestion to enhance motor vehicle safety.
Sincerely,
Stephen P. Wood Acting Chief Counsel ref:l08 d:4/8/90