How to find the center line of a polygon?

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11-20-2017 10:30 AM
VíctorGómez
New Contributor

I need to obtain the axes of a road as they appear in the image, so that they reach the end of the street, with the resulting axis being the longest in the polygon.

I have already tried with the tool "Collapse Dual to Centerlines", using the "PolygonToCenterline (Skeleton)" and there is no way to get it.

Please, if someone could help me, I would greatly appreciate it. Thank you.

I attach an example image with the results I want to obtain. The orange polygon would be the surface of the road and the yellow line would be the axis of the street:

Results

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6 Replies
TedKowal
Occasional Contributor III

This tool may be of some help?   I have no personal experience with it.... http://www.arcgis.com/home/item.html?id=bc642731870740aabf48134f90aa6165 

JoshuaBixby
MVP Esteemed Contributor

If you can post a sample polygon data set to compliment the image, that would be most helpful.

JamesMacKay3
Occasional Contributor

I've used ET GeoWizards' "Create Centerlines" tool to do this with some success, but it has a few drawbacks:

  • It dissolves adjacent polygons, so to get true centrelines I had to run the tool once per feature by first extracting each individual feature to a new class, then merging all of the output classes.  (The tool didn't seem to honour layer selections when I used it @ GeoWizards version 11.2 for ArcGIS 10.3).
  • For polygons that have an ambiguous direction, the centreline usually comes out as a multi-part polyline shaped like the letter X.
  • The centrelines seem to veer off randomly to one side toward the end of some (maybe 5-10%?) of the polygons.
DuncanHornby
MVP Notable Contributor

Another approach is to rasterize your polygons and use the Thin tool. You will need the Spatial Analyst extension. This will require post thinning editing and you playing around with the width parameter. This technique probably works best for small areas due to the requirement to edit the final output. But it does generate the medial axis...

XanderBakker
Esri Esteemed Contributor

There is this tool as part of production mapping: Polygon To Centerline—Topographic Production toolbox | ArcGIS Desktop 

and there is this support page, but it involves manually editing the layer before applying the tool Collapse Dual Lines To Centerline (not available in Pro yet and requires Advanced license in ArcMap) see  How To: Create centerlines from polygon features 

XanderBakker
Esri Esteemed Contributor

I just tried using the tool mentioned by Ted Kowal :

... and the Collapse Dual Lines To Centerline tool that I mentioned 

... but neither seems to be a good solution if your data really looks like that (it's very irregular).