Using Append Parameter in the Add Locations Network Analyst Tool in ModelBuilder?

Question

I am trying to get ModelBuilder to create a route for each row in a .csv file. Each row has one start and stop locations (Point A and Point B). I need to add both start and stop locations to a network layer to create a route. I then need to delete these stops, and iterate back through, creating a route for each record between each start and stop point. In the Add Locations tool help, I read that the Append Parameter might be what I need to use. In the tool dialog box, there is just a checkbox, but in the Python reference it says

• APPEND — Adds the new network analysis objects to the existing set of objects in the selected sublayer.

• CLEAR — Deletes the existing network analysis objects and replaces them with the new objects.

I think I need to do both Append and Clear actions to get what I am trying to achieve but it is just a checkbox in ModelBuilder.

Will I need to use Python code to be able to append, then clear, stops in an iterator model?

I am not very strong writing Python Code and was hoping to use ModelBuilder to get what I need.

I added my model builder file for clarification. The problem lies in the Add Locations tool. It only accepts one pair of Lat/Lon coordinates

Answer 1

1-2. Use Make XY Event Layer to create your start and end points as separate layers. Make sure you specify the spatial reference used for the coordinates. You may need to export these to a shapefile or feature class; test first.

3. Make the Route Layer

4. Add an iterator based on the matching unique name for each route. e.g. if the fieldname is "Name", add an iterator for the field "Name" on the start points layer.

5. Use Add locations from the start points layer based on this iterator -- I think you can make an inline variable and use Select by Attributes. See option 2 in this documentation for inline variable substitution in model builder. Someone else may be able to flush this section out more. For this one, use the option "CLEAR".

6. Use Add locations from the end points layer based on the iterator. Might need to use Select by Attributes as above. For this one, use the option "APPEND". Make sure this step isn't completed until 6 finishes. (Right click on this step, go to Properties, Preconditions, and check the box for the output from the first Add Locations.)

7. Solve the route

8. Export the route polyline. Decide at this time whether you want to have M values (can change in environment settings if you just want the polyline instead of polyline M.) Make sure you give this a unique feature class name.

These resources may help with the advanced Model Builder techniques:

https://www.esri.com/arcgis-blog/products/product/mapping/what-i-wish-i-had-known-about-model-builder-before-i-started-using-it/

http://desktop.arcgis.com/en/arcmap/10.3/analyze/modelbuilder/a-quick-tour-of-advanced-techniques-in-modelbuilder.htm

Answer 2

Wow, so I actually didn't need an Iterator after all. Solution is below. It was using a combination of Clear then Append check boxes that solved the issue.