 Since it is the purpose of the U.S. numbered system to mark the best and shortest route available, an alternate route should be designated only where both routes are needed to accommodate the traffic demand, and when the alternate route has substantially the same geometric and structural design standards of the main marked routing.It is recommended that in case an alternate route is marked, that the shorter and better constructed route be given the regular number and the other section designated as the "Alternate Route".It is further recommended that the Highway Department erect signs at the junction points of the regular and alternate routes giving the distance between the cities or points concerned...