The study is part of an investigation sponsored by the National Research Council to ascertain the optimal colors; back-ground-legend combinations; and spacings of letters, numbers, or words of stimuli used in directing and controlling automotive traffic. One hundred and twenty-three license plates of the states and territories were subjected to analysis for ascertaining the factors involved. Later the colors of the plates were analyzed by a Razek-Mülder color analyzer for wave length as well as reflection factor of the colors.
Proceedings of the Iowa Academy of Science
©1933 Iowa Academy of Science, Inc.
Lauer, Alvhh R.
"Factors Which Influence Visibility in Daylight and under Artificial Illumination,"
Proceedings of the Iowa Academy of Science, 40(1), 185-185.
Available at: https://scholarworks.uni.edu/pias/vol40/iss1/98