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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?
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2 weeks ago
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Hello SakshiKosta. Unfortunately, the Add GTFS To A Network Dataset tool is now deprecated, so I am not able to provide extensive assistance with it. From the error message, it looks like there might be a problem with the spatial reference you have chosen for your feature dataset. I suggest starting over with a new file geodatabase and feature dataset. Make sure to carefully select a valid spatial reference for the feature dataset, and then try again. In general, though, I recommend you switch to using ArcGIS Pro for your transit-related analyses. We have made equivalent tools available in the core product, and these tools are more modern and thoroughly tested, and you can get help on them from Esri Support. Learn more.
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3 weeks ago
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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.
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12-17-2020
07:59 AM
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Yes, that's exactly what it means. The OD Cost Matrix calculation determined that the fastest route between the origin and the destination was just to walk, so it returned the walk time.
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12-16-2020
08:06 AM
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It is not unexpected to get different results with ArcGIS Online and your own network. The network dataset used by ArcGIS Online is a comprehensive dataset using the highest-quality data available from our data vendors. It includes detailed street and path geometry as well as an extensive set of attributes defining the characteristics of the streets, which are used in calculating impedances and restrictions. Your own data may have some differences in geometry - roads in slightly different places, certain roads missing, etc. Thus, the optimal paths between places on the network may differ slightly. You might also have some connectivity errors - places where the streets seem topologically connect but aren't actually logically connected in the network. Even if the geometry of the streets is identical, there is probably a difference in attributes between your data and the ArcGIS Online data. The impedance calculations may be different, and ArcGIS Online might be using some restrictions that you are not. Finally, it should be noted that the ArcGIS Online data contains information about turn restrictions - specific turns that are not allowed or which incur a delay. If you use the "Driving Distance" travel mode, these turn restrictions will be used, even though, for your use case, this probably doesn't make sense. If your own network doesn't have any turn restrictions, it may allow you to build your pipes following the streets around a corner where vehicles are not allowed to turn, like an intersection where you cannot turn left. But for pipes, I presume this doesn't matter. Thus, your data may actually be more appropriate for this situation. Note that there are ways you can adjust the travel modes even when using ArcGIS Online to turn off this restriction, so the issue is not insurmountable. As far as testing your network, it's pretty hard to interpret the results of a Location-Allocation problem. It might be better to do some Service Areas where you turn on the Lines output. This will help you look for holes in your network where things might be cut off. You can also use Route to test some specific point-to-point routes to see if the results make sense. If you are concerned about topological connectivity in your network, you can try using this downloadable sample tool to identify topologically disconnected areas: https://www.arcgis.com/home/item.html?id=b2227f745a6c4e1c94dd57810729d2a9
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12-16-2020
08:05 AM
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There are a few steps/levels that need to be considered, but it seems like everything is mostly set up correctly already. Below is a sort of reverse-order list of things that need to be considered. I'm starting with the part you select when doing your analysis, and it's sort of backing up all the way through the network configuration. You would have to do the steps in the reverse order, but I'm explaining it this way because I think it's easier to understand conceptually. When you do your analysis, make sure to select your "automobil_distance" travel mode on the ribbon. That ensures that you are using the travel mode you specifically configured for your purpose. You need to make sure the "automobil_distance" travel mode is configured the way you want it. A travel mode is essentially just a bucket of other settings that model a particular mode of travel. You want to use an impedance based on distance, so your Impedance property in the Costs section needs to be set to a cost attribute that models distance. In your case, it's set to a cost attribute called "Length", which shows units of meters in your screenshot, so this seems good. You need to make sure that the "Length" cost attribute is correctly calculating the length of the streets. To do that, switch to the Costs tab in the network dataset properties Travel Attributes page, find "Length" in the list of cost attributes, and examine its properties. My guess is that this is the automatically-generated distance attribute you always get when you create a new network dataset, so it's probably just using the shape length of the roads to calculate the length. If this is good enough for you, just leave it. Otherwise, you might want to read more about cost attributes and evaluators so you can properly configure the way it calculates distance.
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12-04-2020
08:10 AM
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If I understand correctly, you want to find the optimal solution that minimizes the distance along the roads from the villages to the wastewater treatment plant potential sites. So, for your network analysis problem, you need to optimize distance rather than travel time. You need to set the Travel Mode option (it's on the Location-Allocation ribbon) to use a travel mode that optimizes distance. Your post doesn't mention what network data source you're using, but if you're using ArcGIS Online or Streetmap Premium, there should be a "Driving Distance" travel mode that solves for distance instead of drive time. If you are using your own network dataset, then it's up to you to construct a travel mode on that network dataset that uses an impedance attribute that calculates distance instead of time. If you clarify what type of network you're using, I can provide further detail on that if necessary.
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12-03-2020
03:26 PM
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Actually, that's not what I recommend. If you want to calculate the travel time between specific pairs of origins and destinations, you need to use the Route solver. OD Cost Matrix only lets you calculate travel time between all origins and all destinations, with some constraints (max travel time, max number of origins to find). It does not let you specify that you want to only calculate the travel time between specifically-designated pairs. To calculate travel time between predetermined pairs, use the Route solver, use the RouteName field in the input stops to designate a unique name for the origin-destination pair. Let's say you want to calculate a route from A to B and A to C and D to F. You need to load A and B with a route name of AB (or something like that, and also A (again) and C with a route name of AC, and also D and F with a route name of DF. When you solve the route analysis, it will calculate three separate routes, one from A to B, one from A to C, and one from D to F.
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11-30-2020
03:20 PM
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If I understand your message correctly, you are trying to count the number of destinations reachable from each origin within a 30-minute travel time. Is that correct? (If you are trying to calculate the travel time from a specific origin to a specific destination - like you have specifically matching pairs - then this is a different problem). You can definitely do this with the OD Cost Matrix tool by using a Cutoff. You can also do this with Closest Facility using a Cutoff and just setting the number of facilities to find to something really big so it finds more than the closest one. Use Closest Facility if you need to examine the traversal result; otherwise, use OD Cost Matrix because it runs faster.
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11-30-2020
03:03 PM
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Yes, the OD Cost Matrix will use any non-restricted network components, including streets and transit lines. Otherwise, how would the traveler walk from their initial location to the bus/rail stop in the first place, and how would they make transfers from one line to another if they have to walk around the block or something? In some cases, walking the whole way may simply be faster or more practical than taking transit. The OD Cost Matrix tool does not store the "traversal result", meaning after it has done the calculation of travel time and distance, it doesn't remember anything about what parts of the network were used. So, in general, for any OD Cost Matrix problem, it is not possible to determine which streets, or transit lines, were used. If you want this information, you can use the Closest Facility solver or the Route solver. For Route or Closest Facility, you can use the Copy Traversed Source Features tool to determine which network dataset components were used and post-process those results however you want. For the old Add GTFS to a Network dataset toolbox (which is no longer supported, by the way), you can use the special Copy Traversed Source Features (with Transit) tool, which wraps the core version of the tool with some special transit information. Regarding when you can add multiple GTFS datasets: In the old Add GTFS to a Network Dataset tool, just dump both of them in as input when you run the 1) Generate Transit Lines and Stops tool. I encourage you to spend some more time with that User's Guide if you're having trouble. Because the tool is deprecated, I cannot provide extensive help with it. As for whether you should or shouldn't combine your multiple datasets - It really depends on what you're trying to do. If you are trying to model the way real passengers travel, then you should probably include both. On the other hand, if you're trying to model the differences in bus service vs rail service, you should probably keep them separate. If you switch to using the newer tools in ArcGIS Pro, there is a way to exclude transit modes in the analysis (see the section on supported parameters here). So, you could build the network to include bus and rail, but for a particular analysis, you could "turn off" rail service using the "Exclude modes" parameter.
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11-30-2020
02:38 PM
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