Interstate Route sign
What does it mean?
The red, white and blue shield identifies a numbered route in the Interstate Highway System. Its number is a route identifier; speed limits, exit numbers and travel directions appear on other signs.
What to do when you see it
- Match the route number to your planned highway.
- Read any NORTH, SOUTH, EAST or WEST plaque with the shield.
- Use advance guide signs to select the correct entrance or lane.
How to recognize it
- Shield with a red upper band and blue lower field.
- White INTERSTATE lettering and route number.
- This illustration uses route 79 as an example.
On the road
Your trip requires Interstate 79 northbound and you see a shield marked 79. Read the direction plaque and entrance signs before choosing the ramp.
Don’t confuse it with
U.S. Route sign
A U.S. route marker uses a black-and-white shield without the Interstate red-and-blue fields.
Speed Limit sign
A speed-limit number appears with SPEED LIMIT on a white rectangle.
Put the meaning into practice
The related quiz includes this sign and other study questions. State practice can also cover local rules; it is not an official DMV exam.
Common U.S. sign recognition, reviewed October 3, 2026. Actual sign values, additional plaques and local rules can change how you should respond.