Uniformity of Signs.
—It would be well if simple standards could be adopted for the entire United States, or at least for each state, and that all signs be set with uniformity. If placed consistently at the same distance and height from the roadway the eye of the traveler will naturally seek them and they will be more easily read. Evans and Batchelder[229] recommend that double-distance board signs be 36 inches long by 17 inches deep when they carry three rows of names and a fourth row for the authority responsible for the sign. If the fourth row is not on the sign 15 inches deep will be sufficient. They recommend that the size of the plain block letters be graduated according to the importance of the places mentioned. The top line for the most important places 4-inch letters; the second row, less important, 3-inch letters, and the third, least important, 2-inch letters. Single direction signs to be 20 inches long and the same depth. All signs on posts are recommended to be placed an average height of 6 feet above the roadway, on houses 9 feet. If the double direction names are placed below each other the board will not need to be so long.
A New Jersey distance and direction sign.
Letters and Colors.
—The letters should be clear and distinct; the style known as block letter is good. The colors should be highly contrasting. Black and white is as good as any; however, Eno[230] thinks that black with yellow and red with white are the best combinations; yellow on black being better than black on yellow. Eno would classify signs as:
Primary, those for warning and directing moving vehicles, vivid yellow letters, arrows or graphics, on a black background.
Secondary, those for stationary vehicles, designating public parking spaces, cabstands, car and bus stops, etc., black on yellow background.
Tertiary, those for the control of pedestrians, designating crosswalks, safety zones, etc., red on white background.