- 1). Place one end of a string on the starting point of your route and hold that end down with your finger.
- 2). Use your other hand to guide the string along your path. Be sure to cover all the curves and turns along the route that you will be taking.
- 3). Mark the point in the string that touches your destination once you have covered your entire route with the string.
- 4). Measure your string from its end to the point that touched your destination.
- 5). Compare your measurement to the map scale. The map scale is usually located in a corner of the map and indicates distance. For instance, if your map scale says that 1 inch equals 10 miles, and your string measured 5 inches, multiply five times 10 to find a road mileage of 50 miles.
Source...