Latest Contributions by MelindaMorang

This page explain the output of the Copy Traversed Source Features tool: https://pro.arcgis.com/en/pro-app/latest/tool-reference/network-analyst/copy-traversed-source-features-output.htm If the routes do not travel over edges, junctions, or turns, then the associated output table will be empty. ... View more

The problem is that your Closest Facility analysis is failing to solve because it has no incidents and facilities in it. You need to first configure your Closest Facility layer and add the desired inputs, then solve it. Once you are convinced that the results are as expected, then you can run Copy Traversed Source Features.   Here is a tutorial to help you learn how to set up a Closest Facility analysis: https://desktop.arcgis.com/en/arcmap/latest/extensions/network-analyst/exercise-4-finding-the-closest-fire-stations.htm ... View more

Hello @DavisTurner. First of all, you did the right thing in removing your GTFS data from the network dataset. BetterBusBuffers is about measuring access to public transit, not about measuring access to other facilities by public transit. Thus, you don't want your network dataset to model travelers taking public transit, you just want to model them walking.   Second, the size of your GTFS data is probably not the issue.  The Preprocess GTFS tool does the heavy lifting and reads in all the data from the different agencies. Once it's passed that point, constructing the Service Area polygon buffers becomes the difficult part. It will definitely take longer if you have more transit stops, but anyway, the slowness is in accounting for overlapping polygons and trying to "flatten" them.   Regarding your error: Are you getting this error on the "Step 1 – Preprocess Buffers" tool? That seems more likely, but please let me know if my assumption is incorrect.   This tool can often be finicky, and it's because it's doing some fairly complex geometric procedures to handle the overlapping polygons. Something strange is happening under the hood, and it's kind of impossible to know why. The only thing to do is to try again by altering some of the settings to change the geometry of the resulting polygons slightly and hoping that the geometry error will be avoided. Here are a few things you can try changing to see if it avoids the problem: Change the Polygon Trim setting to a different value. Update your impedance attribute slightly, like changing the assumed pedestrian walk speed by a small amount. Changing the Buffer Size from 20 minutes to some other number (I know, not ideal...) This last suggestion applies only if you are using ArcMap and not ArcGIS Pro: Calculate a Service Area Index on your network dataset. Basically, we introduced a newer, better algorithm for creating Service Area polygons which fixed a lot of weird geometry problems and made all-around better polygons. This is the default in ArcGIS Pro, but if you want to use it in ArcMap, you have to explicitly choose to calculate a Service Area Index in your network dataset settings. You just have to check on the check-box and run Build Network again.   Note: If you are not using ArcGIS Pro, I recommend switching to Pro anyway to get overall better functionality. The tool might take less time to run or at the very least be less likely to run out of memory.   Hope this helps! ... View more

After calculating your routes, run the Copy Traversed Source Features tool. This tool creates an individual feature for each segment of the network dataset that is traveled upon, and it has a field indicating which route or facility it is used by.  You can do some joins to copy over the number of people from the original data. It also has the ObjectID of the network dataset source it is associated with. You can find all the traversed segments with that ObjectID and sum the number of people associated with each one. ... View more

This tutorial describes how to create a Model using Network Analyst tools: https://pro.arcgis.com/en/pro-app/latest/help/analysis/networks/create-a-model-for-route-analysis.htm   The example uses the Route solver, but the basic procedure would be the same for Service Area or Location-Allocation. ... View more

Hello Seunghoon.  The GTFS specification only started to allow blank values for stop_lat and stop_lon fairly recently when it adopted support for platforms.txt.  The Add GTFS to a Network Dataset toolbox you are referring to is now deprecated and has not been updated since that change. That's why you're getting an error. In general, I do not recommend using the old Add GTFS to a Network Dataset toolbox anymore. Instead, you should use the newer, better tools available out-of-the box in ArcGIS Pro. Learn more here. However, switching to Pro will not actually solve this problem until ArcGIS Pro 2.8 is released (later this year). For now, you will need to manually update your GTFS data. Since the blank stop_lat and stop_lon rows probably represent non-geographic location_type values of 3 or 4, I suggest you just delete the rows. They will not be used in the analysis anyway. ... View more

That build error indicates that the transit stop has not successfully connected to a street feature. There are a couple of likely reasons for this: The street dataset you're using does not cover the entire geographic area that your transit system covers, so there are some stops that cannot find a street to snap to. There are some transit stops in your GTFS data that are in the wrong geographic place. For example, you might have a few stray stops in the middle of the ocean or in Antarctica or something because the lat/lon coordinates are wrong. Your street data covers the correct geographic extent, but it is missing some smaller roads or sections where there are transit stops, so the stops cannot find anything to snap to within the search tolerance. The search distance you used when running the Connect Network Dataset Transit Sources To Streets tool was too small, and for some reason, your transit stops are offset significantly from the street centerlines. For this reason, they failed to snap to the streets. I think you need to take a close look at both the locations of your transit stops and also your street data to determine which of the above cases is causing your problem. Once you've determined that, then you can figure out how to fix it. If the problem is only for a few stops, and they're in an area where you don't expect them to be used for your analysis, then you can safely ignore the build errors. The rest of the network will continue to function. Otherwise, you will need to resolve the issue. You might need to edit the stop locations (or correct the original GTFS and start over), update your street data or use a different street dataset, or re-run  Connect Network Dataset Transit Sources To Streets with a larger search tolerance. ... View more

Are you doing the workflow manually at this point?  You could reduce the amount of work you need to do by automating the procedure using Python or Model Builder.  I don't know that this would reduce the overall time, but at least you could press start and then take a lunch break.  Does this seem like something you might want to do? ... View more

I don't completely understand your workflow, but basically this is what you need to do: In ArcGIS Pro, go to the Backstage area (hit the blue Project button), and click the Python option on the left:   Click Manage Environments to clone your default environment. Once that's done and the new environment is activated, click the Add Packages button. Search for networkx.  You should be able to click the item for networkx in the list and install it. After that, I think you should be good to go. ... View more