ArcView, a geographical information system by ESRI, Inc., was used to identify the mill of each type closest to each FIA plot using straight line distance.
We recognized that the road distance between two points is the relevant measure for explaining stand age. And we also believed that the relationship between straight line distance and road distance might not be linear.
We therefore estimated a circuity relationship between road distance and straight line distance using a sample of 25 pairs of points in the study area. Road distances were computed by Microsoft’s Expedia Streets and Trips 2000, a road mapping software package.