How are the mileages computed?
The Mileage Guide finds the shortest route between city center points or facility locations, taking into consideration all roads including farm-to-market and ranch-to-market roads. The Comptroller’s office uses the Network Analyst module of the ArcInfo Geographic Information System (GIS) from Environmental Services Research Institute, which applies a shortest-path algorithm attributed to E. W. Dijkstra. For more information about the software, see www.esri.com.
