Finding orphaned road segments

1973
5
03-07-2013 04:03 PM
New Contributor
I have a shape file of road network. Some of the roads (polylines) are not connected i.e. they are orphaned. I need to identify those orphaned segments so that I can edit. Is there any tool or ideas that you can help me with? Thank you.
Tags (2)
5 Replies
Regular Contributor II
This is a job for topology and is precisely what it is made for.

To use the topology you have to put the features in a geodatabase, (maybe also a dataset w/in the geodatabase). Then you create a topology. In the topology you create rules. In your case, the rule would be "Must Not Have Dangles" (polylines which have ends that don't connect.) When you check the topology, topology error "layers" are created to identify the errors.

There is a topology toolbar. There are tools on it that allow efficient location and manipulation of features to fix or ignore the topology errors. For example, you can get a list of specific topology errors just in the extent of the view you are in so you can fix them. Then you can pan over and check the topology in another view. You can also check the entire dataset at once.

Links:
http://www.esri.com/news/arcuser/0401/topo.html
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001t000000sp000000.htm (search for dangles for your case).
Reply
0 Kudos
MVP Esteemed Contributor
Just know that you'll have 'false positives' when it comes to cul de sac streets.  In other words, your topology will report more errors than you truly have.
Reply
0 Kudos
by Esri Regular Contributor
Esri Regular Contributor
To find lines not connected on both ends, try:

1. Run Feature Vertices To Points tool (Data Management toolbox - Features) with the DANGLE option to get all dangle points. The output points carry ORIG_FID. Lines not connected on both ends will get two points.
2. Run Frequency tool (Analysis toolbox - Statistics) on the dangle points; specify ORIG_FID field.
3. Run Join Field tool (Data Management toolbox - Join) to join the lines/roads feature class with the Frequency table via OBJECTID and ORIG_FID; specify to transfer FREQUENCY field. Now any lines with FREQUENCY = 2 are orphaned.

Does that work for you?
New Contributor
To find lines not connected on both ends, try:

1. Run Feature Vertices To Points tool (Data Management toolbox - Features) with the DANGLE option to get all dangle points. The output points carry ORIG_FID. Lines not connected on both ends will get two points.
2. Run Frequency tool (Analysis toolbox - Statistics) on the dangle points; specify ORIG_FID field.
3. Run Join Field tool (Data Management toolbox - Join) to join the lines/roads feature class with the Frequency table via OBJECTID and ORIG_FID; specify to transfer FREQUENCY field. Now any lines with FREQUENCY = 2 are orphaned.

Does that work for you?


I'm working on pipeline data checks, and this works perfectly to find any errors when importing multiple data sets from other sources like autoCAD.
Reply
0 Kudos
by Esri Regular Contributor
Esri Regular Contributor
Hey Chris,

I am really glad that it worked for you. Thank you very much for taking the time and letting me and other people know.
Reply
0 Kudos