A check for illogical attribute combinations were performed both interactively and via batch procedures. Visual tests involved the review of check plots. The accuracy of most attributes has not been explicitly tested against independent sources. Item values are compared against a series of user-specified conditions to identify illogical code combinations. No duplicate features are present.
All lines intersect where intended.
No undershoots or overshoots are present. It defines arc-node topology when the LINE option is used. CLIP creates a new coverage by overlaying two sets of features, which are the arcs. Features may have been eliminated or generalized on the source graphic, due to scale and legibility constraints. Horizontal positional accuracy is based upon the use of USGS source Digital Line Graphs from 100,000-scale maps.