Guide, Service, and Route Marker Signs
Guide signs direct you to destinations and routes; service signs point to gas, food, lodging, and hospitals; route markers identify the numbered road. The NJ exam tests sign color and interstate numbering logic more than memorized exit names.
Color and purpose
- Green: guide signs - exits, distances, directions, lane assignments.
- Blue: motorist services - fuel, food, lodging, hospital, rest area.
- Brown: recreation and cultural areas - parks, historic sites.
- Route markers: interstate shield, U.S. route shield, state route circle/oval.
Interstate numbering
- Even-numbered interstates generally run east–west; odd-numbered run north–south.
- One- or two-digit numbers are main routes; three-digit numbers are loops or spurs off a parent route.
- A loop returns to the parent; a spur ends away from it. Mile markers and exit numbers help you track progress.
Worked example
A sign shows an interstate shield with 80. Because 80 is even, the route runs generally east–west. If you also see I-287, the three digits identify a loop or spur route related to I-87, not a separate cross-country route. That tells you it is a local bypass or connector, not the main east–west trunk.
Traps
Confusing blue service signs with route markers; assuming a three-digit interstate is always a loop; and reading a brown recreation sign as a legal route direction. On the road, confirm the route number and direction (east/west) rather than the destination name alone.