topic Re: Grouping line/polygon segments by average value in ArcGIS Pro Questions

Grouping line/polygon segments by average value

Seiji_Nakatani — Fri, 11 Dec 2020 22:05:29 GMT

I am looking for the language to use to even begin researching the process below. I am fairly new to ArcGIS Pro and struggle with finding the right terminology:

Is there a way I can have ArcGIS Pro group high average values along a series of connected/touching line or polygon segments? For example, let's say I have a series of 12 line segments, each with its own value:

5-2-1-9-3-9-2-1-1-1-8-1

I want to group the set of data beginning with the "5" and ending with the second "9" and then give that group the value of its average and/or sum.

My application is this: I have crash counts for street segments and intersections. I would like to ArcGIS Pro locate combinations of continuous street+intersection segments where these groupings have some sort of significance. I know I would need to put minimum and maximum segment lengths and the like.

Thank you for any help.

Re: Grouping line/polygon segments by average value

JoshuaBixby — Sat, 12 Dec 2020 16:53:36 GMT

Polylines and linestrings/multi-linestrings (same geometries, different name depending on geometry object model) are un-closed, ordered collections of paths (segments and/or arcs). Attribution happens at the geometry level and not the part level, so one would not have a polyline in ArcGIS comprising 12 lines segments with each segment having its own values assigned.

Additional data structures are built on top of geometries, e.g., routes define a measurement system on top of polylines, and route feature classes and event tables are used to implement linear referencing in ArcGIS. Since you mention street segments and intersections, I am guessing you are working with a routed feature classes.

It is most helpful to provide some sample or example data along with your description because similar to pictures, a data set is worth a thousand or more words. If you can't share sample or example data, then some graphics illustrating the situation are second best.

Re: Grouping line/polygon segments by average value

Seiji_Nakatani — Thu, 17 Dec 2020 20:16:33 GMT

Thanks for even trying to help with this. Also, thanks for taking time to explain the terminology. I hope you know it is incredibly helpful.

Street data - https://www.denvergov.org/opendata/dataset/city-and-county-of-denver-street-centerline

Crash Data - https://www.denvergov.org/opendata/dataset/city-and-county-of-denver-traffic-accidents

I am not asking anyone to do the project. Just help me know what tools to even begin looking at and reading up on. I really want to learn. After taking these first steps, this will also help me incorporate some of the volume data and other data available to me.

Again, I am able to identify high volume crash clusters or intersections. I am able to attach crash counts to either street segment or intersection. However, in addition to that, I would like to identify stretches of road of at least 5 or so blocks that may need attention do to total crash volume relative to length. Honestly, the min and max street segment count side is something I'd have to consider once I can play with the data.

I really struggle with the language part of this, so I hope I explained myself well.