topic Re: Problem in finding the Shortest Path in ArcGIS Network Analyst Questions

Problem in finding the Shortest Path

Raaj- — Wed, 23 Nov 2011 09:38:31 GMT

Dear Users
The Network Dataset that I've created does not show the shortest route on various roads although no restrictions are given for the roads and the only criteria for the selection of the route was the length of the roads.It does work for certain roads and sometimes it gives the error that there is no route existing between the specified two points although there clearly exists a road.

For your reference I have attached the print screen images showing the problematic locations.
Also attached the shapefile used for creating the network dataset.

Kindly help me to sort out this problem.

Re: Problem in finding the Shortest Path

MichaelRice — Wed, 23 Nov 2011 19:13:02 GMT

It sounds like this is likely a connectivity issue in your network dataset, causing the expected paths to be invalid. You should investigate your connectivity policy in the network dataset properties and also check to make sure that any features you expect to connect to each other actually share a common vertex at the intended connection point (it does not suffice for features merely to touch or cross; they must explicitly share a common vertex at their meeting point in order to establish connection). If this is indeed the case, you can force features that touch to share a common vertex by using the 'Integrate' GP tool.

Re: Problem in finding the Shortest Path

Raaj- — Mon, 28 Nov 2011 10:02:12 GMT

Dear Michael
I have tried, still I am getting the same error.
I don't have any other features to integrate using GP tool. I am having only the raods shp.file with length as attribute.
I request you to help me in sorting this out.If possible can you try creating a new Network Dataset with the attached raods shapefile and let me know your comments.
Thanks for your suggestions and help.

It sounds like this is likely a connectivity issue in your network dataset, causing the expected paths to be invalid. You should investigate your connectivity policy in the network dataset properties and also check to make sure that any features you expect to connect to each other actually share a common vertex at the intended connection point (it does not suffice for features merely to touch or cross; they must explicitly share a common vertex at their meeting point in order to establish connection). If this is indeed the case, you can force features that touch to share a common vertex by using the 'Integrate' GP tool.

Re: Problem in finding the Shortest Path

MichaelRice — Mon, 28 Nov 2011 15:32:53 GMT

I looked at your dataset, and you do have connectivity issues. Change your connectivity policy to be "Any Vertex" (instead of "End Point"), and run the "Integrate" GP tool, and it should work for you (it worked for me on your dataset). Here is a good resource for you to read on understanding connectivity in the network dataset.

I don't have any other features to integrate using GP tool. I am having only the raods shp.file with length as attribute.

You don't need multiple feature classes to run Integrate. You can run it on just your single roads shapefile and it will integrate only the features within this shapefile.

Re: Problem in finding the Shortest Path

MichaelRice — Mon, 28 Nov 2011 16:01:56 GMT

In case it was not clear from my previous post, please also make sure to completely rebuild your network dataset after integrating your features and changing the connectivity policy. The changes will only take effect after a rebuild.

Re: Problem in finding the Shortest Path

Raaj- — Tue, 29 Nov 2011 01:43:01 GMT

Dear Michael
Many Thanks to you.