Advice from Jan Coyne, director, AAA Publishing, GIS/cartography division

A good place to start is by checking out the legend, the most overlooked element of a map, to see how the mapmakers represent things like parks, rest areas, and road classifications (U.S. highway, interstate, etc. — typically, the brighter and thicker the line, the more major the road). Also check the legend for the copyright year to be sure the map’s not outdated. Find streets or cities by looking them up in the index. It will give their coordinates — what we call bingo keys — based on the grid numbers and letters at the edges of the map. Orient yourself by checking for an arrow pointing north. Major U.S. east-west interstates have even numbers; north-south interstates have odd ones. In most states, interstate exits are no longer sequential (1, 2…) but indicate mileage from state borders, going west to east on even routes, south to north on odd.