Post-WWII America was a time of great changes in American life. New ideas and people flooded into our country enriching the melting pot that has always been the United States of America. By the 1960s and 1970s pluralism had moved from small insular communities into the mainstream and changes were needed to adapt to the fact that not everybody spoke or read English.
One subtle change came in the early 1970s with the adoption of traffic signs that had less English text on them. These signs were more iconic in appearance, directing people with arrows, specific colors and simple pictures.
In 1972 the Kansas Highway Commission issued a small document on the changes to Kansas signs reflecting the changes that were taking place nationwide. The first paragraph of the pamphlet states:
"The Kansas Highway Commission, during the next few years will replace many existing highway signs. Some of the new signs going up use symbols instead of words, others use color. Due to the sign cost the change to the new will be gradual as the older type wear out. The public will need to remember both the old and the new type signs for a few years."
You can view this document at the State Library of Kansas' KGI Online Library. The pamphlet includes black/white graphics of the signs, showing "new type" and "old type." I'd bet that some of these old signs would be a great collector's item nowadays.
KANSAS HIGHWAY SIGNS ARE CHANGING!