Problem: Network Analyst: Clicking the Full Extent button zooms to the extent of the spatial reference
If the Full Extent button is clicked when there are network analysis layers in a map, it may zoom to the full extent of the spatial reference rather than the extent of the features in the underlying feature classes.
This occurs when one or more of the network analysis sub-layers does not have any features in it. Since the extent of an empty feature layer is based on the domain of the spatial reference and the full extent is the combined extent of all the layers in the map, the full extent can be much larger than the actual features.
Solution or Workaround
Use one of the following options to avoid this behavior:
Do not zoom to the full extent until network locations have been added to the network analysis sub-layers and solve has been performed. Add unlocated barriers if your analysis problem does not otherwise require them. Having features in the analysis sub-layers causes the full extent button to use the extent of the features rather than the extent of the spatial reference.
Instead of using the Full Extent button to zoom out, right-click on the network layer in the table of contents and click on Zoom to Layer. This will zoom to the extent of the features within the network which will most likely be the correct extent.
Adjust the domain of the network dataset's spatial reference to a more appropriate value based on the underlying data. That way, the extent of the spatial reference and the extent of the features will be close to the same.