Guide and Informational Signs
What guide signs do
Guide and informational signs help you navigate and find services. They are not commands, but misreading them causes wrong exits and late lane changes. Green signs give destinations, distances, exits, and route guidance; blue signs show services; brown signs show recreation and cultural sites.
Core rules
- Route markers: Interstate routes use the blue-and-red shield; U.S. routes use the white shield; New Hampshire state routes use a square marker with “NH” and the route number. The shape tells you which road system you are on.
- Destinations and distances: Green signs list places and mileage, usually in the direction of travel. Exit tabs and advance signs tell you which lane to use. Distances are in miles.
- Services: Blue signs indicate gas, food, lodging, hospitals, rest areas, and camping. They do not guarantee that a business is open.
- General information: “WELCOME CENTER,” “REST AREA,” and “NO SERVICES” signs tell you what is available ahead. “TO” signs direct you toward a route you are not yet on.
Worked example
A green sign reads “Concord 18” above “Boston 65,” with an exit tab for Exit 12. You are heading south and want Concord. The sign tells you Concord is 18 miles ahead in your direction; it does not mean the exit is 18 miles away. You should read the exit tab and advance lane signs separately. Reasoning: destination mileage and exit location are different pieces of information.
Traps
Confusing a route marker with a destination sign; reading a distance as an exit number; assuming a blue service sign means the service is open; missing a “TO” sign; and changing lanes too late because you read only the destination and not the exit tab.