Signal Lights and Colors.

—The railroads in all these years have not come to a common usage of colors in signaling. All roads use red for stop, danger. Some use white and some green to proceed with caution; white and green are both used for clear, proceed. Here white is the same as yellow, because lanterns using oil burn with a yellow light which railroad men call white. Electric signals may be white in reality.

There now seems to be a demand for standardization and at a meeting of the American Association of State Highway Officers (1922, at Raleigh, N. C.) a color scheme was recommended that may become a standard for both motorists and railroads. One of the difficulties is that red and danger are no longer properly associated because of the common use of the red for tail lights of automobiles, for sandpiles or other street obstructions, for the tops of semaphores, and for various other purposes. The story is told that not long ago a bridge was being repaired and a red light was placed at one side. The signal was intended as a warning that the autoist slow down and proceed with caution. The driver of an approaching car took the lantern to be the tail light of an automobile. He swung to the left to clear the obstruction and plunged down an embankment.

TRAFFIC TOWER ON FIFTH AVENUE, NEW YORK CITY

It would be better if red should never be used as a precaution signal but only as a stop signal, but at the present time that cannot be done because automobiles now carry, and most states require it by law, a red light behind. The color once considered a sign of danger has become almost meaningless. Red lanterns are placed on roads, or at bridges, or in the street where the road is not impassable but merely hazardous and the light in reality means proceed carefully. If colors are to be signals to tell whether or not to stop on account of danger, to proceed cautiously or to go ahead without fear, they should be standardized and their proper use protected.

The code of colors as recommended by the Association of State Highway Officials is:

Color Green to mean proceed, the way is clear.

Color Yellow to mean that caution shall be exercised.

Color Red to mean stop.

The Association urges abolishment of the red for automobile tail lights and the substitution of yellow (white). There are other reasons why this should be done; one of them, a white light will illuminate the number tag much better than a red light. In fact Ohio requires a red light shining out behind and a white light to illuminate the tag. On the other hand by the different colored lights one can distinguish whether one is going toward the front or back of an automobile, a thing of importance, sometimes.

This may be far enough to go at the present time, but later the standardization of other signal and guide lights would be well. The red light on street obstructions should be abolished. Better a bright white light for with good illumination the danger will often disappear.