How to find junction connected to three edges?

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02-27-2020 11:15 AM
PaulFrissora1
New Contributor

I have two layers: Layer A has Junctions as a Point file; Layer B has edges as a Line File. 

The problem: I'm looking for junctions that are intersected by three (no more, no less) lines. Like this: 

              

                                                                     \

                                                                       \   

                                                                         x-------------                                                                                                                                                                             /

                                                                     /

I'm looking for a way to find these junctions with either a selection of by making a separate shapefile. It seems the way to do this might be through creating a Geometric Network or Network Analyst dataset, but I haven't been able to find much info in the forums and documentation online. 

Has anyone done this before?  

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1 Reply
MelindaMorang
Esri Regular Contributor

If you already had a network dataset, you could use the arcpy.nax.NetworkDataset class (requires ArcGIS Pro 2.4 or higher) to iterate over edges (the lines) and retrieve the lists of junctions attached to those edges.  Then you could count which junctions show up more than three times.  However, creating a network dataset can be somewhat arduous and is probably overkill for this problem.  You would have to do a lot of filtering of the cursor results to make sure you were only getting the junctions that you created and not the automatically created system junctions that the network dataset creates.

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