Network Analyst and Urban Paths Layer

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11-14-2011 06:27 AM
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New Contributor III
Hi,

I wonder if anyone has any suggestions as to how to solve this problem with the new urban path layer fro Ordnance Survey.

I've created a Network Dataset from the ITN Layer and the New Urban Paths Layer.  All connections are fine and it runs ok, however it often does not recognise points (facilities) that are lying close to the urban path layer i.e. Path nodes/lines and Connect nodes/lines.

It seems to prefer the ITN road network over the urban path network.

Because its for pedestrians and they can go anywhere, I'd like them to have equal heirarchy i.e. paths, primary roads A-roads, B-roads can be traversed equally.

Is there a way to do this?  I tried looking at the heirarchy notes but I couldn't make that much sense of them.

I can move them to a new location but because I'm using a population centred X Y location, I am reluctant to do this.

Any help would be appreciated.

Thanks

Scott
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Esri Regular Contributor
Hierarchy is useful for long distance routing. Say going from Paris to Berlin.

If you are solving for pedestrian routes then you do not need to set up a hierarchy.

All connections are fine and it runs ok, however it often does not recognise points (facilities) that are lying close to the urban path layer i.e. Path nodes/lines and Connect nodes/lines.

It seems to prefer the ITN road network over the urban path network.


What is this "it" that does not recognise points lying close to the urban path layer? What are you trying to achive?


I can move them to a new location but because I'm using a population centred X Y location, I am reluctant to do this.


Are you having trouble snapping your start/end points to the urban path layer? If yes, you can turn off the ITN layer to snap on in the Locations Tab of the Route layer properties. At the bottom are the snapping options where you can set which layers point will snap to.

Jay Sandhu
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New Contributor III
Thanks for taking the rime to reply.  I've abanadoned the hierarchy idea and yes, it seems to be a snapping issue.

I created a network datasest consisting of the ITN and Urban Path layers. It's made up of Road, Connect and Path nodes and links.

I'm trying to make a service area with polygon breaks at 400, 800 & 1200 metres for 1007 facilities.

When I tell the facilities layer to snap to my Road and Urban Path layer only (and not road or path links) in the Network Location window, the network dataset recognises nearly all of the positions but the polygons produced are in the wrong positions i.e. NOT above the facilities points!

Alternatively, when I tell the facilities layer to snap to the paths, connections, roads nodes and links and my urban path layer it doesn't locate al the points but the service area polygons generated are at least in the right position i.e. above the facilities points.

Either way it doesn't produce the polygons I need. There should be 3021 from my 1007 facility points but there never is - and it varies depending on what I snap the points to.

Should I re-run the points I did not get the 1st time round or is there a way round this?

Also, in the Service Area window, should I set the snapping settings before loading the locations or after?  And should I do the same with the polygons layer?

Thanks again for your advice and I'd be grateful if you could shed some light on this problem.

Kind regards

Scott
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