topic Re: Point to Nearest Polygon in ArcGIS Pro Questions

Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 14:22:43 GMT

I have a map with a layer of point locations throughout the US and a layer of polygon sectors. All of the US is contained within a sector. I am trying to find the closest polygon to each location by driving distance and driving time. I haven't been able to find the functionality that will allow this analysis since each location is contained within a polygon. Does anyone have any insights whether this is possible and if it is how it could be done?

Re: Point to Nearest Polygon

JayantaPoddar — Wed, 07 Feb 2018 15:06:53 GMT

Did you try Near—Help | ArcGIS Desktop ?

Re: Point to Nearest Polygon

DanPatterson_Retired — Wed, 07 Feb 2018 15:13:22 GMT

To get road drive times and distance you would require the network analyst extension.

How detailed of a solution do you need? As Jayanta suggests, the Near tool or Near as Table (if you have the license otherwise http://www.arcgis.com/home/item.html?id=f96ede37dcd04c2e96dc903a4ce26244) using polygon centroids would probably suffice for a continental scale study ... at least in the first instance.

Perhaps some elaboration on what you are trying to achieve in the end would help with further suggestions

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 15:23:08 GMT

I have arcGIS Pro Advanced with spatial analysis. Near will not work because I need drive distance and drive time. Unfortunately centroids will not work as the precision required is at least a mile. The main problem I have is finding the driving distance/time to the nearest polygon. If the points were not already contained in a polygon a Spatial Join set to closest and driving distance would be perfect. There are about 3,500 points and 450 polygons so removing the resident polygon is not a practical option. I would share the file or more specifics but the material is sensitive. I am reasonably new to GIS so please let me know if I can provider a better explanation. Thank you for the replies.

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 15:24:00 GMT

Thanks Jayanta, see my reply to Dan Patterson below for why this solution doesn't work in my instance.

Re: Point to Nearest Polygon

DanPatterson_Retired — Wed, 07 Feb 2018 17:08:54 GMT

But you don't have the Network Analyst which is the major issue since you require driving distance.

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 17:40:04 GMT

I do have network analysis but I don't see a way to utilize it because of the issues as stated above.

Re: Point to Nearest Polygon

JakeSkinner — Wed, 07 Feb 2018 17:42:40 GMT

Hi Matthew,

If you have an ArcGIS Desktop license you will have an ArcGIS Online subscription. Not sure if you, or anyone in your organization, has activated this, but if so you can use the Find Nearest analysis tool. You can specify Drive Times as a the measurement.

Note: This tools will use credits. With 3,500 points you will be charged 1,750 credits to perform this analysis.

Re: Point to Nearest Polygon

DanPatterson_Retired — Wed, 07 Feb 2018 17:45:59 GMT

I just picture the destinations being an intersection between the polygon(s) and the lines (roads) rather than the location within the polygon. Have you considered just producing an intersection as described or are you concerned that each intersection point might be associated with two polygons?

Re: Point to Nearest Polygon

XanderBakker — Wed, 07 Feb 2018 17:55:13 GMT

Would closest facility work for you? Make Closest Facility Analysis Layer—ArcGIS Pro | ArcGIS Desktop

... and a tutorial can be found here: Tutorial: Closest facility—ArcGIS Pro | ArcGIS Desktop

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 17:56:48 GMT

That was my initial inclination to try but it results in an error. The program indicates that the nearest location field must be a point for driving distance when I attempt to run it as such. My nearest location is a polygon which is the crux of my issue.

Re: Point to Nearest Polygon

XanderBakker — Wed, 07 Feb 2018 18:01:39 GMT

How large is the polygon and what does it represent?

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 18:38:23 GMT

The polygons range in size from most of a western state like WY to several dividing a city. They are administrative areas and there are values for each of the polygons that I want to compare to the one in which it currently resides. (i.e., the closest polygon to facility A is polygon X. polygon X has a higher value M than the polygon facility A is currently in). I need to find this by drive time and drive distance from the facility to the edge of the polygon. Basically that means that I can't use a central point or points on vertices because there is too much precision loss. I hope this makes sense. I wish I could just share the file but that's not possible currently.

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 07 Feb 2018 18:46:16 GMT

I guess that I'm not really sure how to go about creating that in the current model. I can deal with multiple returns outside of arcGIS as long as it has driving distance.

Re: Point to Nearest Polygon

XanderBakker — Wed, 07 Feb 2018 18:59:17 GMT

Dan Patterson‌ mentioned this before:

I just picture the destinations being an intersection between the polygon(s) and the lines (roads) rather than the location within the polygon. Have you considered just producing an intersection as described or are you concerned that each intersection point might be associated with two polygons?

This would generate many points, one for each intersection of a road (over which one will enter the area) with the same value M. Doing a closest facility will return the drive time, drive distance for the nearest location. It seems that this "hack" could be a solution to get what you are after.

So, I would go with Dan's solution, although I still don't understand what this value M represents and why it is able to represent such large areas...

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 14 Feb 2018 00:03:39 GMT

I have been thinking about my problem and believe that your approach would be the best approach. I was hoping you could provide a little guidance as to how I would treat the roads as lines. This would be hundreds of thousands of points to it is obviously not able to be done by hand.

Re: Point to Nearest Polygon

XanderBakker — Wed, 14 Feb 2018 03:00:20 GMT

Some pointer to get you started:

Convert the polygons to polylines using Feature To Line—Help | ArcGIS Desktop (Advanced license required)
Intersect the polyline outlines of the polygons with the road (or make a selection of the roads that intersect first to speed up the process of intersection) using Intersect—Help | ArcGIS Desktop make sure to use lines as input and points as output (see: How Intersect works—Help | ArcGIS Desktop )
The resulting points should still have a reference of the original polygons used to create them.
Then probably do the Closest facility analysis—Help | ArcGIS Desktop to see which point (read polygon is the nearest).

Re: Point to Nearest Polygon

MatthewNickeson — Wed, 14 Feb 2018 03:44:11 GMT

Thank you everyone, you have all been awesome! I’ll give your suggestion a go tomorrow. I’m only 3 weeks into my arcGIS experience and I really appreciate the community’s willingness to help.

Re: Point to Nearest Polygon

RebeccaStrauch__GISP — Wed, 14 Feb 2018 18:28:36 GMT

Matthew, make sure to come back to thus thread and mark one answer as correct, and others as helpful to get to that point. That will help other in the future and will close out the thread. A summary is always nice too. Interesting topic/problem.

Re: Point to Nearest Polygon

MatthewNickeson — Thu, 15 Feb 2018 15:11:56 GMT

Thank you Xander and Dan, your suggestions are very helpful. I apologize for what is probably a novice question but I'm not sure how to get the roads as an input feature to the intersect. I should clarify that I have Pro Advanced with Spatial Analyst but not Network Analyst. I was incorrect when I stated that earlier. I would prefer not to purchase the Network Analyst extension but can if needed.