Our distances are not driving distances, but are calculated as a 'straight-line' (or point-to-point) distance that starts in Pleasant Hill. A straight line distance ignores obstructions like rivers, canyons, lakes, et cetera - it's truly a line drawn from Point A (ie- Pleasant Hill) to Point B.
Our distance measurements begin at a specific point in Pleasant Hill. The point that we are using is located at these GPS coordinates - Latitude: 31.9302, Longitude: -88.2145 [Map]. In this case, the coordinates for Pleasant Hill have been provided by the Geographic Names Information System (GNIS).