M4-1, ''ALTERNATE'' Route Marker Sign, Various Sizes & Reflectives

MUTCD M4-1 Sign, ALTERNATE Sign, available in various sizes and retro-reflectivities.

Section 2D.02 Application (Manual on Uniform Traffic Control devices (MUTCD) -U.S. department of Transportation Federal Highway Administration (FHWA))

Support:
01 Guide signs are essential to direct road users along streets and highways, to inform them of intersecting routes, to direct them to cities, towns, villages, or other important destinations, to identify nearby rivers and streams,parks, forests, and historical sites, and generally to give such information as will help them along their way in the most simple, direct manner possible.