How to Navigate an Offline GPS Road Map

Apr 5, 2025

Today is National Road Map Day, and we thought that it would be the perfect opportunity to help our fellow road trip enthusiasts build their skills. Learn the ins-and-outs to reading a road map properly, so you can navigate to “parts unknown” and live out your off-road adventure dreams. Although modern smartphones can do a world of tasks, sometimes bad reception means our GPS apps don’t load quickly, and a paper map may be necessary. Enjoy our helpful tips and tricks and a veritable “what’s-what” of map iconography, so you can be safe no matter where you’re going.

Helpful Terms and Symbols to Know When Reading a Road Map

Color: Cartographers will color code a map based on its many different purposes. Check the legend on your road map or atlas to figure out where you’re driving through, which roads are major highways, county roads, residential streets, etc. It will also help you understand the terrain, environment, and proximity to water or coastal regions. It can also be used to determine elevation, or even state and county lines or town and city districts.

Contour Lines: If your map includes topography, you’ll see different lines that indicate elevation such as mountains, hills, valleys, etc. There will be solid, dotted, straight, and wavy lines. This can also help you determine which vehicle to take on your road trip depending what type of terrain you’re driving on.

Compass Rose: A compass rose is a symbol used to display the orientation of “cardinal directions” (north, south, east, west) This helps navigators discern which direction is the Earth’s magnetic north when using a physical compass. Every paper map includes a compass rose to illustrate true North at the top of the map. You can use a compass to help you get a better sense of where you are.

Grid System: Maps are divided into a grid format with horizontal lines marked by letters and vertical marked by numbers, this will help you find the exact coordinates and location using longitude and latitude.

Map Index: Maps often include an alphabetical list of locations in an index. City maps will include street names or major landmarks of the region. County maps will include major highways and major cities and towns. A State map will have significant cities and towns. Oftentimes these are coded with letter-number combos which match a point on the map.

Map Legend: All maps contain a legend or a key which explains what each symbol represents and what every line, mark, or colour means. This will help you decode the difference between major interstate highways and smaller back roads. It may also help identify hills and mountains or bodies of water.

Orientation: Make sure you have your map so that the compass rose shows “N” at the top of your page, this will help you align your current position on the map and navigate which direction you need to travel on the next leg of your route.

Road Types: Different types of roadways will be marked with line thickness, color, and specific symbols or markers (check your specific map legend for the full key) Generally, Interstate Highways are marked with a shield that has the route number and are a thick red or blue line; US highways are marked with a symbol with the route number and a differently colored thick line than the interstates; State Highways will be thinner lines and may be marked with route number; Local roads are the thinnest line and are generally marked in black. Unpaved roads may be marked with a dashed or dotted line. On a GPS, dotted lines may indicated closed lines or under construction areas.

Scale Ruler: When plotting a course using a paper road map, you’ll need to use the map’s integrated “scale”: a line marked in inches which represents distances. Use that scale line to determine the “miles by inches” between your destinations to get a scale of the distance. For example, 1 inch of distance on the map may equal 10 miles of actual distance driving. Grab a

ruler and measure the distance between your road trip points and multiply. Without knowing the scale of your map, you may miscalculate distance between destinations or time it takes to travel to and from.

Topography/Terrain symbols: Some maps include lines, shading, and color to explain the terrain around you. Using a topographic map means you’ll be able to identify mountains, hills and valleys, desert versus field, etc. Many maps include basic topographical elements to explain basic geographic features of the region.

How to Navigate Using a Road Map

Take a look around you and try to find a street sign, highway marker, or landmark and match it to the region on your map. You might notice a mountain, lake, or river in your vicinity that will help you identify the region you’re in. Cross-reference this to your paper or digital map, and try to find two landmarks within eye shot of you to help pinpoint the area you’re in.

If you have a compass on your smartphone/tablet or even your vehicle, ensure that your map is oriented correctly to your compass. This is called “declination” and helps you correctly locate which direction you’re traveling in. Circle or mark your area on the map and then find your destination, and check the roadways in between to plot your best course of action. Use the map legend to figure out the scale of distance and how many miles you must travel.

Always make sure to find checkpoints along your route, so that you can refer to the map to record how far you’ve traveled and if you’re headed in the right direction. If you make a mistake, this can also help you reorient yourself and get back on track.

Bear in mind that road maps and terrain maps will differ slightly, but the same general principles will apply. When you’re hiking and using a topographic/terrain trail map, be sure to mark your starting point and end point, and bring your compass with you. Pay close attention to the specific legend/key and symbols or colors so you remain on the correct path.