topic Re: Find overlapping distance in ArcGIS Network Analyst Questions

Find overlapping distance

MuninderKumar — Mon, 31 Oct 2022 07:47:40 GMT

I have the GTFS data with me in which some of the trips are overlapping. I want to find out the linear overlapping distance. Is it possible to do so in arcgis pro, and if yes, how to do it?

Re: Find overlapping distance

MelindaMorang — Mon, 31 Oct 2022 21:22:58 GMT

Hello. GTFS trips are not explicitly geographic. A trip is an instance of a vehicle traveling along a specific sequence of stops at a designated time of day. If your GTFS dataset has a shapes.txt file, then the trips will be associated with specific shapes, which are geographic and are intended to map the actual paths traveled by the vehicles between stops. You can add your shapes.txt file to ArcGIS Pro using the GTFS Shapes To Features tool.

If you are truly asking for the linear overlapping distance between trips, then I'm not sure how to help you, since many trips may use the same shape, and you would have to do a bunch of joins or other accounting to count the number of trips using each shape and then the overlapping distance between shapes.

As far as the overlapping distance between shapes...

You might be able to use the Intersect tool to get a line representing only the intersecting portions of multiple shapes. Then you could get the length of that line. The geometry of the features created from shapes.txt might not overlap exactly, though. You might be able to use some of the Conflation Tools to modify the geometry to match better before doing the intersect.

Can you tell me more about what you're really trying to do? I might have better suggestions if I understand that. Is this, by any chance for the Directional Miles calculation for the FTA's National Transit Database annual reporting requirement?

Re: Find overlapping distance

MuninderKumar — Tue, 01 Nov 2022 05:50:43 GMT

I have the shapefile of the trips. Now I want to find the overlapping trips and their distance.

Re: Find overlapping distance

MuninderKumar — Tue, 01 Nov 2022 05:55:21 GMT

No it's my own project.

Re: Find overlapping distance

MelindaMorang — Tue, 01 Nov 2022 15:48:11 GMT

Okay, well hopefully my suggestions to use the Conflation tools and Intersect will still work for this.

Re: Find overlapping distance

RamB — Sat, 26 Nov 2022 20:10:51 GMT

Hi,

If you have an exact overlap it is easier to solve. If you have no shape in GTFS, then they should overlap exactly (as straight lines) . Ofcourse I am assuming routes overlap on ground too. If they do not overlap, then try the previous suggestions.

Ram