Standards

 This week we learned how to determine the quality of road network data. This was accomplished by determining the horizontal accuracy of the ABQ Streets (shapefile of road centerlines from Albuquerque, NM and StreetMap USA (shapefile of street centerlines from StreetMap USA) compared to reference points of true intersection locations. Inside the study area, I created two new feature classes of 20 test points for the ABQ Street shapefile and StreetMap USA shapefile. The criteria followed was using a good intersection, meeting sampling rules (minimum of 20% in each quadrant and >10% diameter apart), and matching locations in the two datasets.  After I completed the test points, I created a new feature class named reference points and created 20 points depicting the true intersection of my test points. To determine the accuracy statistics, I added XY coordinates to the feature classes to later add to the NSSDA Horizontal Accuracy worksheet.

City (ABQ) Accuracy Statement:  Using the National Standard for Spatial Data Accuracy, the data tested 14.47 feet horizontal accuracy at 95% confidence level.

StreetMap USA Accuracy Statement:  Using the National Standard for Spatial Data Accuracy, the data tested 160.00 feet horizontal accuracy at 95% confidence level.