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I received a data file containing city sidewalks as a polygon feature. I am running ArcGIS 10.3.1, with a Spatial Analysis extension. For the purpose of my data analysis, I need these polygon features to be single line features.

I used the "Polygon to Line" tool, which produced a line feature of the perimeter of each polygon (not what I'm looking for). From this output, I used the "Collapse Dual Lines to Centerline" tool, with a maximum width of 1 foot. This basically produced the same output as the input, with the exception of two ouliers (not centerlines).

Can anyone provide a solution or suggest a workflow?

enter image description here

  • Do you have arcscan extension? – FelixIP Jul 28 '17 at 21:02
  • @FelixIP if asker has ArcGIS Desktop 10.1 or later then they have access to ArcScan: esri.com/software/arcgis/extensions/arcscan – PolyGeo Jul 28 '17 at 22:42
  • @FelixIP. Yes, I have access to ArcScan. – GISjaclyn Aug 1 '17 at 18:24
  • Use it. Apply raster cell size equal approximately 1/3 of average width of footpath – FelixIP Aug 1 '17 at 19:10
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I tested raster approach using ArcScan. Firstly I buffered these lines by 1 m:

enter image description here

  • Added short integer field to buffers and populated it by 1 using field calculator
  • Set environment extent equal to one of the buffers, cell size = 0.7 m
  • Used polygons to raster tool and above field to create intermediate raster
  • Used raster calculator to replace NO DATA values by 0
  • Created new polyline layer and start editing session on it
  • Used ArcScan toolbar to point to 1/0 raster and Generate Features from menu of this toolbar
  • Applied Collapse Dual Lines To Centerline while still in editing session (output to different folder!)

Output:

enter image description here

closely depicts original lines. Moreover it is topologically correct, i.e. lines have common vertices only at their ends and it was not a case with original (note colors in legend)

I converted all the vertices of "fromScan" lines to points, removed overlapping ones and run NEAR tool (using ORIGINAL as near features) to find out how far are resulting lines from original. Statistics window:

enter image description here

This means that ArcScan is brillinat piece of software perfectly suitable for your task.

  • I'm going to attempt this method today. Thank you, @FelixIP. – GISjaclyn Aug 2 '17 at 15:43
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My guess is that you're looking for a way to create a centerline from polygons? See this ArcGIS Tech Article: How To: Create centerlines from polygon features

  1. Convert the polygon layer to a line feature class by using the Polygon to Line tool. The tool is located in the Data Management toolbox > Features toolset.

  2. Remove the lines enclosing the polyline layer.

    a. Start an edit session.
    
    b. Select a line.
    
    c. Use the Split tool, if necessary, and split the line so the
    particular line is detached from other lines. 
    
    d. Select the line segment, and delete. 
    
  3. Save the edits, and stop the edit session.

  4. Create the centerlines by using the Collapse Dual Lines To Centerline tool. The tool is located in the Cartography toolbox > Generalization toolset. The centerlines are displayed in the map.

  5. Run the Integrate tool on the layers to align the features.

  • 1
    This is perhaps applicable to a few polygons, won't work for hundreds – FelixIP Jul 28 '17 at 21:00

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