GIS and E911/NG911 Peer Exchange
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Figure 4 Description

Overview

Figure 4 displays images showing the measurements and definitions for four road data ratings. Source: Pennsylvania DOT (PennDOT).

Values

1. Average Proximity Rating
   100 - (Average Proximity Distance * 100)/Zone Distance
   Average distance between two edges approximately by fitting the geometry of the edges to a straight line and then computing the normal distance between corresponding endpoints of the line and dividing by two.
2. Relative Orientation Rating
   Indicates how closely the orientation of the primary edge matches that of the secondary edge. Based on 100 * cos(orientation angle)
3. Length Difference Rating
   Length of road as compared to original road. Length difference (in feet) < 1 ft < 50 ft < 100 ft
4. Length in Range Rating
   Measures how much of the total extent of the secondary edge is within the specified distance of the primary edge. In other words, what percentage of the total length of the secondary edge falls within the Zone Distance of the primary edge. Length in Range Rating = 100 * Length in Range/Total Length

Presentation

Figure 4 describes four PennDOT Road Ratings.