Interstate Route Sign: Meaning and What to Do
The red, white, and blue shield with INTERSTATE across the top and a number below identifies a route in the Interstate Highway System. The design shown carries an example number; the actual number tells you which Interstate you are on or being directed to.
Interstate Route Sign
Interstate numbering follows a pattern worth knowing: even numbers run east-west and odd numbers run north-south, with the numbers rising from south to north and from west to east. Three-digit routes are loops and spurs around cities. Shields appear on their own posts along the route and inside green guide signs at interchanges.
What to do when you see the interstate route sign
Use the shield to confirm you are on the intended route and to choose the correct ramp at an interchange, where several shields with cardinal direction plaques may appear together. Interstates are limited-access highways, so expect high speeds, no cross traffic, and entry and exit only at ramps.
The signs it is confused with
Tests pair it with the U.S. Route shield, a white shield on black, and the State Route marker, whose shape each state chooses. The red and blue Interstate shield is the same in every state, which is why the exam expects you to know it.
Signs are one topic of ten on every test
Every state practice test covers signs, signals, and markings among its ten topics, with every answer explained. Pick your state and see how its exam asks about signs like this one; it is free, with no sign-up.
Choose your stateQuestions about the interstate route sign
What does the interstate shield mean?
The road is an Interstate highway with the number shown. The shield marks the route along its length and on guide signs at interchanges.
What do even and odd interstate numbers mean?
Even numbers run east-west and odd numbers run north-south. Three-digit numbers are loops and spurs serving a city.
What kind of road is an interstate?
A limited-access highway with no cross traffic, no signals, and entry and exit only by ramps. Pedestrians, bicycles, and very slow vehicles are generally prohibited.
What are the small NORTH and SOUTH signs above the shield?
Cardinal direction plaques that tell you which direction of the route a ramp or road serves. Read them before choosing a ramp.
How does this sign appear on the written test?
As a route-marker recognition question with the U.S. and state route markers as the other choices.