Migrating from ArcGIS 8.x and 9.x
If you have a network dataset that was created using the previous release of ArcGIS, you can upgrade the geodatabase then upgrade the network dataset to take advantage of the latest functionality. This process is discussed further in Upgrade Dataset. Be aware, however, that if you upgrade the geodatabase, you won't be able to use it in previous versions of ArcGIS.
Creating a network dataset from data stored in an ArcGIS geodatabase from ArcGIS 9.0 or earlier involves the following steps:
- First, migrate your geodatabase.
- Move all source feature classes into one feature dataset.
If you have multiple feature classes in different feature datasets or if they are outside feature datasets, move them into one feature dataset. Only the feature classes within the same feature dataset as the network dataset can be used as sources for the network dataset.
- Ensure that the source feature classes do not participate in a geometric network or in other network datasets. If the source feature classes participate in a geometric network or any other network dataset, they cannot be used as sources for a network dataset.
- Inspect the geometry of the feature class.
To perform network analysis, the network source should have vertices at every intersecting edge. This is essential for establishing connectivity. If you have lines intersecting each other with no vertex at the intersection, there is no connectivity at that intersection. You can modify the feature class in ArcMap to ensure that coincident vertices are present where required. One option is to have the feature class participate in a topology to insert vertices at places of intersection.
- Inspect the attribute table of the feature class.
You need a cost attribute in your network dataset for performing network analysis. If you have at least one numeric field in the feature class representing length or time, you can use that field to create a cost attribute. This cost attribute can be used as an impedance for network analysis. If you have no such field in the feature class, do one of the following:
- Create a new field in the feature class, add length or time values to it, then use it to create a cost attribute for the network dataset.
- Create a new cost attribute in the network dataset and assign values to it using a constant evaluator, a field expression that uses other fields of the feature class, or a VBScript.
- Optionally, you can create a turn feature class and turn features if you want to model turn information.
- Prepare the design for the network dataset.
It is essential to understand the various components of a network dataset and prepare a design of the network. This includes modeling connectivity and thinking about network attributes and their evaluators.
- Create the geodatabase-based network dataset.
This creates the schema for the network dataset.
- Build the network dataset.
Building a network dataset involves the creation of network elements from the sources, establishment of connectivity, calculation of network attributes, and the setting of properties for directions.