Highway Route 21 Sign - Official Roadway Marker #3509950 (License: Personal Use)

This image shows a standardized route marker sign, commonly used in the United States and other countries to denote highway or state route numbers. The bold, sans-serif numerals ensure maximum visibility and legibility at speed, adhering to MUTCD (Manual on Uniform Traffic Control Devices) specifications. Its simple black rectangle with white numerals is designed for durability and recognition under varied lighting conditions.

Used on official roadways, maps, GPS systems, and transportation documentation to identify Route 21; matches user intent for navigation, road signage reference, or transportation design research.