topic Re: Network dataset in ArcGIS Network Analyst Questions

Network dataset

OlawumiLanlehin — Mon, 18 Mar 2013 00:16:28 GMT

I am currently working with network dataset I got from the Open street map for London (UK) street map, after building the dataset in ArcCatalogue it returned some errors but built the network dataset anyway I could not perform some analysis like the closest facilities and other analysis. The best route analysis drew some route but I doubt it is accurate as the visual display does not look logically correct. I am not sure if it is anything to do with my dataset. What could be wrong?

Re: Network dataset

JoeBorgione — Mon, 18 Mar 2013 13:45:02 GMT

What could be wrong?

Short answer. A lot of things, especially:

Connectivity and Impedance Values

My suggestion is to get more familiar with NA by working through the tutorial.

Re: Network dataset

OlawumiLanlehin — Mon, 18 Mar 2013 14:11:27 GMT

Short answer. A lot of things, especially:

Connectivity and Impedance Values

My suggestion is to get more familiar with NA by working through the tutorial.

Could it be the dataset because I have worked through the dataset again? I just am wondering the the fields required to for the dataset to work alrightt.

Regards,

Olawumi

Re: Network dataset

AndreasHesse — Mon, 18 Mar 2013 16:00:04 GMT

I am not familiar with the OSM data quality of the London area, but when I used OSM Data from Hamburg with the Network Analyst I for example had problems with oneway streets (editing needed for ArcGIS to recognize them properly), prohibited turns onto highways (missing z-levels, bad connectivity set-up) and maxspeed data (many values not existent).

Not being able to perfom some types of analysis like Closest Facility seems rather odd though. What exactly happens when you try to do that?

Re: Network dataset

JaySandhu — Mon, 18 Mar 2013 18:21:05 GMT

With OSM data, make sure you are using "Any Vertex" connectivity and not the default End Point.

Jay Sandhu

Re: Network dataset

OlawumiLanlehin — Tue, 26 Mar 2013 18:03:51 GMT

I am not familiar with the OSM data quality of the London area, but when I used OSM Data from Hamburg with the Network Analyst I for example had problems with oneway streets (editing needed for ArcGIS to recognize them properly), prohibited turns onto highways (missing z-levels, bad connectivity set-up) and maxspeed data (many values not existent).

Not being able to perfom some types of analysis like Closest Facility seems rather odd though. What exactly happens when you try to do that?

Thanks for your response. When I ran the closest facility the last time here are the warning error I got: "Warning: Location "57 A4020, LONDON, W5 5" in "Incidents" is on a non-traversable network element position.
Warning: Location "101 RIDGEWAY, LONDON, W3 8" in "Facilities" is on a non-traversable network element position.
Warning: Location "195 A502, LONDON, NW1 8" in "Facilities" is on a non-traversable network element position.
Warning: Location "STATION STREET, E15, E15 1" in "Facilities" is on a non-traversable network element position.
Warning: Location "BONDWAY, LONDON, SW8 2" in "Facilities" is on a non-traversable network element position.
Warning: 0 location(s) in "Incidents" are valid. Need at least 1 valid location(s).
Warning: 0 location(s) in "Facilities" are valid. Need at least 1 valid location(s).
Error: Insufficient number of valid locations in "Facilities" or "Incidents".

My minute Field rows are all null value, how can I calculate this to return figures?
Regards

Olawumi

Re: Network dataset

AndreasHesse — Wed, 27 Mar 2013 15:30:43 GMT

Location XY is on a non-traversable network element position.
Warning: 0 location(s) in "Incidents" are valid. Need at least 1 valid location(s).
Warning: 0 location(s) in "Facilities" are valid. Need at least 1 valid location(s).
Error: Insufficient number of valid locations in "Facilities" or "Incidents".

Your Incidents and Facilities are on street elements that are either not connected to the rest of the network (for example because of little gaps from the endpoints to the next street elements), or there are some restrictions active that prevent using this street (use the network identify tool to check, or turn restrictions off in the analysis settings).

My minute Field rows are all null value, how can I calculate this to return figures?

For example with the field calculator and a little math using a speed value (30mph?) and the shape length attribute.

Re: Network dataset

OlawumiLanlehin — Fri, 29 Mar 2013 20:21:33 GMT

Your Incidents and Facilities are on street elements that are either not connected to the rest of the network (for example because of little gaps from the endpoints to the next street elements), or there are some restrictions active that prevent using this street (use the network identify tool to check, or turn restrictions off in the analysis settings).

For example with the field calculator and a little math using a speed value (30mph?) and the shape length attribute.

Thanks for your prompt response to my queries. I am happy to tell you that it worked. However I am struggling with service area analysis with this error messsage "Warning: All network edges were excluded from line/polygon generation for "all facilities" in "Facilities".

Regards,

Ola

Re: Network dataset

RahelehHosseini — Thu, 03 Aug 2017 16:11:24 GMT

Hi Olawumi Lanlehin,

Have you figured out the problem with London road network?

Currently, I am doing my dissertation and I need to run a network analysis (Closest facilities) on London roads. I have a similar problem as yours and was looking through websites and blogs to find a solution which I came across to the discussion that you've started.

I just was wondering whether you might be to help me now. Many thanks in advance.

looking forward to hearing from you.

Regards

Shohreh

Re: Network dataset

JaySandhu — Thu, 03 Aug 2017 16:19:56 GMT

If you are using Open Street Map data, I would suggest that you look at the tools at the link below to help build a network dataset that can be used with ArcGIS.

ArcGIS Editor for OpenStreetMap | Overview

Alternatively you can use the closest facility service on ArcGIS.com and do your analysis there. You will be paying some credits to use that. But the network of London is available ready to use.

What are the ArcGIS Online network analysis services?—Help | ArcGIS Desktop

Jay Sandhu

Re: Network dataset

RahelehHosseini — Thu, 03 Aug 2017 17:08:56 GMT

Hi Jay,

Thank you for your prompt reply.

I have ArcGIS 10.4 installed on my laptop and this editor tool is for 10.5 and isn't compatible with 10.4.

Also, my other concern is about editing London OSM roads, which consists of almost 200,000 feature!!

Re: Network dataset

JaySandhu — Thu, 03 Aug 2017 17:30:34 GMT

Hello Shohreh,

The OSM tools have been around for many releases of ArcGIS. You can get the 10.4 version here:

https://www.arcgis.com/home/item.html?id=c18d3d0d5c62465db60f89225fdd2698

I would still caution you that if your goal in the dissertation is closest facility, then do not spend time maintaining the data unless you have other uses for it. Use the ready-to-use services in ArcGIS and call the closest facility solver. These ready-to-use services show up in the Catalog once you have signed into ArcGIS.

You can set up a trial account that gives you 200 credits for 21 day. Details here:

http://www.arcgis.com/features/free-trial.html

Regards,

Jay Sandhu

Re: Network dataset

RahelehHosseini — Fri, 04 Aug 2017 13:40:02 GMT

Hi Jay,

Thank you very much for your support.

I used the ready-to-use service in ArcGIS for the closest facility tool which was amazing. But unfortunately, it didn't work for generating service area. I was wondering whether you might have a solution or any tips for the service area solver?

Many thanks in advance.

Shohreh

Re: Network dataset

JaySandhu — Fri, 04 Aug 2017 15:04:40 GMT

Shohreh,

Glad the CF service worked. Can you tell me what did not work with the Service Area service? It should be pretty straight forward. That is, add the facilities point feature class and set the break values and run it. If it did not work, what error or warning was returned?

Jay Sandhu

Re: Network dataset

RahelehHosseini — Fri, 04 Aug 2017 15:22:12 GMT

I did exactly the same but nothing happens. It doesn't even show any error messages or warning.

This the screenshot which shows how I set up the setting. After pressing OK button it doesn't do anything.

When I click on the Service Areas service, the Generetae Service area window opens and some layers appear in the Table Of Contents but after pressing OK all the layer which was added to the TOC will be removed.

Re: Network dataset

JaySandhu — Fri, 04 Aug 2017 15:43:52 GMT

When you start the tool, it adds empty layers to the TOC which can be populated such as the Firestations are being passed in. When you click ok, these layers are removed from the TOC and passed to the ArcGIS.com service. After a few seconds (depends on how large the job is), a Service Areas layer is added to the TOC. This should have the results. You can go to the Geoprocessing drop down and click Results. Expand the Current Session and see that the GenerateServiceAreas is listed there. Expand it and expand the messages to see what is going on. Is it still running?

How many firestations are being passed in?

Jay Sandhu

Re: Network dataset

RahelehHosseini — Fri, 04 Aug 2017 15:52:50 GMT

I think it's still running. As there is a sand watch sign beside the generate service area and service area and output layer are empty yet.

There were 113 fire stations.

Re: Network dataset

JaySandhu — Fri, 04 Aug 2017 17:13:58 GMT

Shohreh,

If it has not finished then it could be that some problem happened. You could test by trying it on a smaller subset of the firestations, say 10. Can you tell me the username of the arcgis.com login? Maybe we can figure out what may have happened. Do note that service area charges 0.5 credits per break value per facility.

http://www.arcgis.com/features/plans/credits.html

Jay Sandhu

Re: Network dataset

RahelehHosseini — Mon, 14 Aug 2017 15:26:47 GMT

Hi Jay,

Sorry for my delay. I was away last week and didn't have access to ArcGIS and my data.

After a conversation with my supervisor, I've decided to leave service area for now. Again thank you for your support.

Do you which source the ready to use service is using for the network? I mean where does it get the data for example if I want to run it to consider the traffic? Where does it get the traffic data from?

Regards

Shohreh