1. In the Network editor window, click the Edit mode icon 
.
2. In the Network window, click the Main zones button.
3. In the network, double-click the centroid or within the boundary of the main zone whose zone polygons you want to merge.
4. Right-click in the network display.
The Main zones shortcut menu opens.
5. Select the Merging of the zone polygons entry.
The polygons of the zones of the main zone are merged.
