Our distances are not driving distances, but are calculated as a 'straight-line' distance that begins in Concord. A straight line distance ignores obstructions like rivers, canyons, lakes, et cetera - it's truly a line from Point A (ie- Concord) to Point B.
Our distance measurements begin at a specific point in Concord. The point that we are using is located at these GPS coordinates - Latitude: 33.5457, Longitude: -87.7303 [Map]. In this case, the coordinates for Concord have been provided by the Geographic Names Information System (GNIS).