Guide and Informational Signs: Navigating by Color
Guide and informational signs help you navigate and find services; they do not impose rules. Colors carry the meaning, and the exam tests whether you can pick the right color for destination, service, or recreation, and use Illinois' milepost-based exit numbering.
Colors and content
- Green: destinations, distances, route numbers, exit direction. On Illinois interstates exit numbers match mileposts, counted from the state line or route origin.
- Blue: motorist services - gas, food, lodging, hospital, rest area, phone. A blue sign tells you a service exists nearby; it is not an endorsement or a guarantee of hours.
- Brown: recreation and cultural attractions - parks, historic sites, trails.
- White with black legend: regulatory signs or small informational plaques, not guide signs.
Worked example
You are westbound on an interstate and pass a green sign reading Exit 145 - Rockford 1 MILE, followed by a blue sign with a gas pump and a food symbol. The green sign says the exit is one mile ahead and the exit number equals milepost 145, so your odometer can confirm your position. The blue sign says fuel and food are available at that exit, but it does not tell you which brand, price, or whether they are open. Plan the stop but verify as you approach.
Traps that cost marks
- Using exit numbers as a count of exits rather than mileposts.
- Treating blue service signs as endorsements of a business.
- Looking for a destination on a brown sign when the route is the issue.
- Missing EXIT ONLY or RIGHT LANE MUST EXIT plaques under green signs, which change the lane into a mandatory exit.