Latest Contributions by MelindaMorang

Okay, that makes sense. If you are creating your GTFS dataset specifically for the purpose of using with Esri tools, don't bother with transfers.txt. You might be able to manually edit in this information by applying specific delay times or restrictions using the StopConnectors feature class in the data model and adjusting the network's evaluators to use that information. We do not have any courses related to multimodal networks. The tutorial you found is the best resource. Feel free to post more questions here if you have them, though. ... View more

You are correct that the transfers.txt file is not used when converting GTFS into the Esri Network Analyst public transit data model.  I have investigated this in the past, but I found that I could not find reliable GTFS datasets using transfers.txt in a consistent way that I could use for testing. This is somewhat compounded by the extension to the GTFS specification for pathways and levels that was added a few years ago and which, in my opinion, is quite confusing and hard to follow. If you are able to share your GTFS dataset, I would like to see how you are using transfers.txt. I may be able to enhance our tools in the future to make use of transfers.txt, or at the very least advise you on how to incorporate the information into the existing data model. ... View more

Hello Russell.  Unfortunately, the procedure used within BetterBusBuffers to parse the overlapping geometry of all the Service Area polygons sometimes has problems like this. If you haven’t already, please take a look at this post: https://community.esri.com/t5/arcgis-for-public-transit/invalid-topology-error-when-running-betterbusbuffers/m-p/1023915#M328 I suspect the answer there may also help you out. Other than tweaking those settings, I don't really have a good solution for you. You could definitely try to clip out the stops for only the area you care about, although I do not have any tools to help you do that easily. The good news is that I am currently working on a ground-up rewrite of BetterBusBuffers that will be included as a core tool in the next release of ArcGIS Pro (2.9 - late 2021 or early 2022). The rewrite uses a different methodology for handling overlapping polygons (a rasterization and sampling approach) which will hopefully avoid these problems and make the final output less unwieldy. I know this doesn't help you out in the short term, but perhaps next time you have to do this task, you can use the improved version. ... View more

Just wanted to post an update now that Pro 2.8 has been released and the aforementioned new documentation topics are available. Hopefully these topics will help you and other users better understand the arcpy.nax solver object workflow. Set analysis inputs: https://pro.arcgis.com/en/pro-app/latest/arcpy/network-analyst/setting-analysis-inputs.htm Access analysis outputs: https://pro.arcgis.com/en/pro-app/latest/arcpy/network-analyst/accessing-analysis-outputs.htm    ... View more

I guess so. But I really don't know what your professor wants. If you do not understand the assignment, you should really ask your professor. ... View more

I think you should start with our tutorials so you can understand the types of modeling and analysis that the Network Analyst extension can do. We have tutorials to explain the different types of analysis and tutorials to help you create a network dataset using your street data. These tutorials don't use python, but you should still start here so you can understand conceptually what you're doing. Once you know what you want to do, you can read about how to do network analysis with python. Good luck! ... View more

Please provide specific details about your assignment and what you're confused about. There's not enough information in your question for me to understand what you need help with. ... View more

Nice to hear from you, too, Olivia. Small world, heh. Hmm, actually the red polygon does not look like the typical Service Area Index type polygon output. It definitely looks a little smoother, as if you're using a larger polygon trim value.  It's hard to say, though. 10.3 to 10.7 is a pretty big jump, and changes made in the intervening years to the polygon generation algorithm or to the underlying TIN engine used to generate the older style polygons could easily explain the difference. Since the polygons shown in your image look generally similar, I wouldn't worry too much about these small differences, though. My general recommendation is to turn on the Use Service Area Index optimization to get better Service Area polygons. Even better: Upgrade to ArcGIS Pro. ... View more

That is the correct approach for what you're trying to do. If that doesn't work, I suggest you put your data in a file geodatabase and try again. Shapefiles are old and weird, so maybe that's causing an issue. If that still doesn't work, you will probably need to call Support. ... View more

I took a quick look. I still looks like a connectivity problem to me. Your metro line does not have vertices at the locations where it intersects with the streets, so the network dataset does not allow travel between the streets and the metro line. ... View more

By "connector features", I just meant providing some kind of geometry to ensure that the transit lines have a connection to streets at the locations of stops. As long as the Extend Tool did that for you successfully, that should be all you need. Everything you said make sense. Nothing obvious stands out to me. If you can post your data or some screenshots of your network dataset configuration, I could take a quick look. ... View more

I can't really tell what's going on in your screenshot. I can't see whether the route is actually traveling on the metro line or if it's using only pedestrian lines. Assuming it is not using the metro line at all, my guess is it's probably a connectivity issue. If the pedestrian lines and metro line are not connected to one another properly, the traveler will not be able to switch between them. Assuming the start and end locations are on the streets, the traveler can't get onto the metro line, so they just walk through the streets instead. Here is some documentation to help you understand the connectivity options in a network dataset: https://pro.arcgis.com/en/pro-app/latest/help/analysis/networks/understanding-connectivity.htm In general, the most common problems are these: Your metro lines and streets don't physically connect in any way. They do not share endpoints or vertices. In this case, you need to add some connector features that connect the metro stops with some street location. You have connections between metro lines and streets, but those connections do not have either an endpoint or vertex on both features.  Or, they share a vertex, but the connectivity policy is "End Point".   Incidentally, if you are trying to model public transit in a network dataset, we have a more sophisticated way to do that. Learn more in this tutorial: https://pro.arcgis.com/en/pro-app/latest/help/analysis/networks/create-and-use-a-network-dataset-with-public-transit-data.htm ... View more