When any edge is deleted from network, associated system junctions will remain undeleted in the network. Those system junctions accumulates in the geodatabase which can cause significant growth especially in large networks. There is a sample solving this task at edndoc site (http://edndoc.esri.com/arcobjects/8.3/samples/editing/working%20with%20network%20features/delete%20junctions%20with%20edge/deletejunction.htm). It would be nice to have this implemented directly as standard part of the system, e.g. like an option for users to choose whether to delete junctions or not.