Guide and Service Signs (route markers, interstate shields, exits, destinations, services, mileposts)
What this domain tests
Guide signs direct drivers to routes, destinations, exits, and services. The exam tests interstate shields, U.S. and state route markers, exit signs, destination signs, service signs, and mileposts. Maine uses mile-based exit numbers, and the Maine Turnpike uses mileposts, so exit numbers and mile references are linked to distance rather than sequential order.
Core rules
- Green guide signs give destinations, directions, distances, and exits.
- The interstate shield is blue, red, and white; U.S. route markers and state route markers are different shapes and colors.
- Exit signs show the exit number and destination; a mile-based number tells you the distance from the state line or route origin.
- Blue service signs show gas, food, lodging, and hospitals; brown signs show recreation and cultural attractions.
- Mileposts are small green or white markers used for location and emergencies; they are not speed limits.
Worked example
A green sign reads EXIT 45, MAIN STREET, 1 MILE. The green color identifies it as a guide sign; EXIT 45 is the mile-based exit number, and 1 MILE is the distance to the exit. The driver should move right after confirming the destination, not at the last moment. A blue food sign before the exit is a service sign, not a guide sign to the exit itself.
Traps that cost marks
- Reading a milepost as a speed limit or route number.
- Confusing a blue service sign with a green destination sign.
- Assuming exit numbers are sequential rather than mile-based in Maine.
- Waiting until the exit ramp to change lanes after passing the advance guide sign.