I have a project where I would like to take all of the right of way areas in a county and categorize them based on type/ownership (state right of way vs. county vs. private and maintenance responsibility). All of this information is already contained within the street centerlines layer. Seems like the logical way to do this would be to create a right of way layer where I buffer the street lines out to the parcel edges and create polygons using a few chosen attributes of the street centerline data.

Currently, the closest I have come with my workflow is:

  1. Buffer the Street Centerlines (Dissolved on Category, Type and Name)
  2. Erasing using the Tax Parcels as the Erase Feature
  3. Integrate Street Centerline Buffer to edge of tax parcel polygons (this is especially helpful to fill in cul de sacs and larger right of ways surrounding larger highways)
  4. Snap the Centerline Buffer to the Tax Parcel Line (Edge snapping)

My issues with this, is the end result includes many overlapping polygons and the manual cleanup of data would take up quite a bit of time. I cannot have overlapping areas, because acreage calculations would double count in those areas.

My assumption is that I'm not the first person to have a need to solve this problem--and that there is an easier, better way to attempt to do what I am doing. Logically, this doesn't seem like a difficult task...but when I put the processes together they just don't seem to be the best way to solve the issue. Does anyone have any insight into an easier way? Or can point me to somewhere where a similar task is being solved? I have done several searches for expanding out streetlines to polygon borders, but have not received any helpful results. I'm also likely making this way more difficult than it needs to be.

I'm currently going through the process manually to verify things are working properly, so I'm welcome to solutions that involve out of the box ArcGIS tools as well as ArcPy. I need to make this repeatable, so best case, I am able to write a script or create a model. Worst case, I heavily document this to put in the instructions of how to create the next instance of this report.

  • A better starting point might be to erase all the parcels from the county boundary. Have you seen what that looks like yet? In theory, that should yield all ROW.
    – crmackey
    Jan 4, 2016 at 21:13
  • To get just the right of way, that works. Unfortunately, it's one large polygon and I found that splitting it to make each street a separate record that includes the necessary information is even more of a bear than what I've outlined above. In addition, I get water features, etc that are not tied to a parcel. (My next use of this would be to do a similar for waterways and separate pieces of land without ownership that are associated with the rivers in the area).
    – MaryBeth
    Jan 4, 2016 at 21:23
  • What if you union or intersect the output of the single ROW polygon with the centerline buffers? Or, a spatial join of your road centerlines to the single ROW polygon may also get you close (using the ONE TO MANY option and keep only features that intersect). I think there's going to be a good deal of clean up either way.
    – crmackey
    Jan 4, 2016 at 21:30
  • The results seemed to be cleaner with the steps I'm currently using. Creating the ROW from an erase and joining was my first thought. But using unions or intersects seemed to make the data even less usable--the steps above gave me the cleanest output so far...but still not ideal. I was thinking that what I was attempting to do would be pretty common and I'd find a better way. I'm trying to cut down on cleanup time and increase accuracy in calculations.
    – MaryBeth
    Jan 5, 2016 at 14:39


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