Intersect v/s Union

[YusufMohamedshah]

I am new to ArcGIS. I am trying to use Linear Referencing Tool: Overlay Route Events. I have two dbf files: One is a line file and another is a point file. I want to do an overlay of point file to line file and get the results as a UNION. But I get an error. However if I do INTERSECT it works fine.

So the question is: Why an INTERSECT works but UNION does not work. If I want the results as UNION, is there a work around.

I would appreciate any input.

Thanks

[TimWitt2]

Union does not work with a point or a line feature. It only works with polygon features.

What is the goal of doing what you want to do? That might help us to help you.

[YusufMohamedshah]

I am working with highway data. I have two files: a roadway centerline file in which each segment is identified by RouteID, FromMeasure and ToMeasure. And a roadway signs file in which each sign is identified by RouteID and FromMeasure. My goal is to locate the signs on the roadway and produce an output file with all the roadway segments with signs info attached. Hence I wanted to do  UNION so that I can get all the roadway columns as well as Signs columns in the final file.

Thanks

[NeilAyres]

Sorry, files???

Is this spatial, well at least the roadway center lines?

If you have roadway centerlines as a feature class with measures (PolylineM), then you can join the signs table to it by creating route events. This problem has nothing to do with union or other geometry overlay operations.

[YusufMohamedshah]

Thanks Neil for your reply.

I am new to GIS world hence I am not using correct language. I have two dbf tables: Roadway which is line data in which each segment is identified by RouteID , FromMeasure and ToMeasure and a Signs table which is point data in which each sign is identified by RouteID and FromMeasure. My goal is to locate the signs on the roadway segments and produce an output file with all the roadway segments along with signs. Also whenever a sign matches the roadway segment it should be broken at that point by creating a new FromMeasure and ToMeasure.

Thanks

[RebeccaStrauch__GISP]

You may want to take a look at the Near command

Near—Help | ArcGIS for Desktop

This can add an XY coordinate of the closest point on the line feature.  If you intent is to have the point on the line (not sure that it is), you could create a script to move the location to the new coordinates, or create a new featureset using the new coordinates.

[TimWitt2]

You could create a spatial join ArcGIS Desktop

[YusufMohamedshah]

The spatial join has option of using only one common column name between the two tables. I need following logic to get the output:

If RouteID between the two files match and FromMeasure from Signs fall between FromMeasure and ToMeasure from Roadway then output. Also break the segment where the match takes place. So for example if a segment has two signs, the segment should be broken at the points where sign matches. So there will be three segments with same RouteID and updated FromMeasure and ToMeasure.

[DanPatterson_Retired]

So your data are in the form as noted here

http://desktop.arcgis.com/en/desktop/latest/guide-books/linear-referencing/about-overlaying-event-da...

and you were doing this...

http://desktop.arcgis.com/en/desktop/latest/guide-books/linear-referencing/overlaying-events-interse...

and from here...

http://desktop.arcgis.com/en/desktop/latest/tools/linear-ref-toolbox/overlay-route-events.htm

did you see this paragraph?

If either the input or overlay event properties are type POINT, the output event properties must be defined as type POINT when an INTERSECT overlay is performed. The output event properties must be defined as type LINE when a UNION overlay is performed.

and what was the error

[YusufMohamedshah]

Following is the screen capture of the Overlay Route Events tool: When I execute it I get the error shown below: