From Here to There: Road Signs
As early motorists ventured away from their own neighborhoods into strange country, they needed some way to keep from getting lost. There were no signs to direct people to where they wanted to go. When the first signs appeared, they were usually put up by business people who hoped to attract new customers. Often a group of merchants got together to promote a special route that would go through their own towns. A number of these routes developed.
Other road associations sprang up all over the state, each one marking the way with a painted pole to guide motorists to the cities along the route.
The Red Ball Road was marked by a white strip of pain on fence posts with a red dot in the cent. This road was marked between St. Louis, Missouri through Iowa to St. Paul, Minnesota in about 1908. The avenue of the Saints, or Highway 27, is on this route today. The White Way is marked with a white strip of paint on post between Omaha, Nebraska through Iowa to Chicago, Illinois in about 1911. Highway 92 follows this route today.
Eventually there were so many different markers that the travelers were almost as confused as they had been before the poles were put up. Finally, in the 1920s a numbering system developed, and new signs with numbers replaced the old poles. Although states had their own numbering systems, a cross-country system of numbered national highways helped travelers who were driving through more than one state.