W4-1 (R/L): Right/Left Merge Sign, Various Sizes and Reflectives

MUTCD W4-1 (R/L) Sign, RIGHT MERGE Sign / LEFT MERGE Sign, available in various sizes and retro-reflectivities.

Section 2C.01 Function of Warning Signs: (Manual on Uniform Traffic Control devices (MUTCD) -U.S. department of Transportation Federal Highway Administration (FHWA))

Support:
01 Warning signs call attention to unexpected conditions on or adjacent to a highway, street, or private roads open to public travel and to situations that might not be readily apparent to road users. Warning signs alert road users to conditions that might call for a reduction of speed or an action in the interest of safety and efficient traffic operations.