Why does Network Analyst compute non-zero distances between the same locations?

Discussion created by critz on Jun 28, 2010
Latest reply on Jun 28, 2010 by jsandhu-esristaff
Some details:

1.  Same geocoded file is being used for Origins and Destinations.

2.  We've compared SourceID, SourceOID, PosAlong, and SideOfEdge from the Origins file to those in the Destinations file. SourceID, SourceOID, and SideOfEdge values are exactly the same.  PosAlong is different for some of the cases. However, a > 0 distance is being calculated for approximately 5% of the cases where all four variables are exactly the same.  Most of these distances are close to 0 (about 90%) but 10% are greater than 0 when rounded to hundredths of a mile.  Several are over 3 miles for the same origin and destination...

3.  We are not sure why PosAlong for some cases is different when the source of the Origins and Destinations file is the same.