Once you travel out of town, you'll probably be using some part of the nation's highway system (although with many state and national highways
passing directly through urban areas, you might use them for speedy in-town trips as well). Here's how to locate the three main types:
State highways typically have a highway marker that's a number within a white circle or oval. These roads are usually two lanes (sometimes
switching to four lanes in more urban areas), so they're not always the fastest routes for long distances.
Federal highways have a shield-shaped marker surrounding the highway number. Like state highways, they're usually two to four lanes. But what they may lack in long-distance speed, they
can usually make up in the history behind them (and along them), as they were the first national highways built in the U.S.
Finally, there's the interstate highway system, four- to eight-laned behemoths that criss-cross and link up the country. These are probably your fastest choice for longer distances,because unlike most federal and state systems,interstates are limited access highways, which means you can only get on or off at specific intersection points, usually marked as white squares on the map's road line. The highway marker
for the interstate system is a shield-shaped symbol (although unlike the federal highway marker, interstate markers are usually colored).
The interstate will be the boldest road marked on any state or national map.