White on Blue.
An improved form is given below:
Yellow on Black.
Traffic Guides
(From Eno’s “The Science of Highway Traffic Regulation.”)
Widening the roadway before reconstruction has begun will also furnish room for the passage of vehicles. Of course under either of these two last methods the passing vehicles are more or less of a nuisance to the constructor and if a reasonably direct detour entirely away from the work under construction can be maintained in satisfactory condition so much the better. While the traffic must be inconvenienced to some degree by detours the fact that an effort is being made by the road authorities to make the substitute as pleasant as possible will leave a “good taste in the mouth” of the traveling public which is worth while whether that traffic is local or from a distance.
Location of Detour Markers.
—The location or arrangement of detour markers in reference to the traveled way has received considerable attention. Of course the first signs are the barricade warning and at the barricade. In Illinois the State Department of Highways requires the barricade warning to be placed about 400 feet from the barricade. The map signs of Wisconsin, Minnesota, and North Carolina are used also as barricade signs. Any driver, not authorized, passing a barricade is by the laws of some states subject to arrest and fine. Detour arrows are placed at road intersections in such a manner that traffic going in either direction may follow the arrow. Illinois uses a black arrow on a white background. Iowa has somewhat similar signs except that the color scheme is a white arrow on a black background. The word “detour” is printed above and below the arrow and the one painted out that is not needed after the sign is erected. In Iowa upon primary (State) roads the district engineer, and upon county roads the county engineer, is held responsible for the following:
First.—He shall determine whether or not a detour is needed.