Dissolve operation on a Network dataset without improvement

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02-22-2013 12:06 AM
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Occasional Contributor II
Hi,

I performed a dissolve operation on a network dataset but I didn't notice any change.
If I understand the dissolve correctly, it transforms a street that is not crossed by any other street and that is made up of multiple segments into a street with only one segment. Am I wrong?
If what I said above is correct, the dissolve didn't do that on my network dataset. I still have the same streets table and the same junctions table as before dissolving.
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New Contributor III
Hi,

I performed a dissolve operation on a network dataset but I didn't notice any change.
If I understand the dissolve correctly, it transforms a street that is not crossed by any other street and that is made up of multiple segments into a street with only one segment. Am I wrong?
If what I said above is correct, the dissolve didn't do that on my network dataset. I still have the same streets table and the same junctions table as before dissolving.


If your network dataset uses junctions that are not system junctions then you will not see a reduction in the street features.
If your network dataset has turn features at every junction then you will not see a reduction in the street features.
If your network dataset does not have a street name field and every junction has 3 or more edges connected then you will not see a reduction in the street features.

These are some of the cases where dissolve will produce no improvement.  The most likely is that you have a junction source that has no actual field information but is not a system junction source.  If you remove this source from your original network, rebuild the network, and dissolve then you will see a reduction in the street feature count.

Dissolve Network will not dissolve through a junction if it does not have a system junction.

Doug

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a b,

The output of the dissolve is impossible for us to determine because we do not know what/if you dissolved the polylines against a field such as the street name.  If you did, then multiple segments of the same street name in that case would become one feature.

Also we need more information about the network.

First, did you rebuild the network after the dissolve was complete?

Second, are you creating junctions only at the end of line segments or at all intersections?

Third, have you tried creating a new network with the dissolved data? If not, this would be an easy way to see if the network is in fact altered.

Best,
Chris B.
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Occasional Contributor II
Thanks for the reply,

The dissolve tool, that is found in the Network Analysis toolbox, has two parameters: the first is the path to the NA dataset and the second is the workspace where the output dissolved NA dataset (not only the streets layer) will be created. So the original NA dataset is not modified by the dissolve operation.
And there is no "dissolve field" parameter. So I didn't dissolve the network against any field.
The network dataset I work with was built before dissolving it. And the output dataset was also built after dissolving.
The junctions are created only at the end of the segments.

I hope this information is relevant for the diagnosis 🙂

Thanks
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New Contributor III
Hi,

I performed a dissolve operation on a network dataset but I didn't notice any change.
If I understand the dissolve correctly, it transforms a street that is not crossed by any other street and that is made up of multiple segments into a street with only one segment. Am I wrong?
If what I said above is correct, the dissolve didn't do that on my network dataset. I still have the same streets table and the same junctions table as before dissolving.


If your network dataset uses junctions that are not system junctions then you will not see a reduction in the street features.
If your network dataset has turn features at every junction then you will not see a reduction in the street features.
If your network dataset does not have a street name field and every junction has 3 or more edges connected then you will not see a reduction in the street features.

These are some of the cases where dissolve will produce no improvement.  The most likely is that you have a junction source that has no actual field information but is not a system junction source.  If you remove this source from your original network, rebuild the network, and dissolve then you will see a reduction in the street feature count.

Dissolve Network will not dissolve through a junction if it does not have a system junction.

Doug

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Ok thanks. I guess the dissolve in my network didn't do any improvement because I didn't specify the street name field (that should be specified in the directions tab??? right?).
The street name field in my layer is very incomplete: more than a third of the streets don't have a name in my network... So I guess it's impossible to perform correctly the dissolve operation.

Thanks!
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