This is the first post of a three post series in which I will be covering pipe networks created from GIS data.
Using this feature new to 2012 you may have noticed that GIS data in the form of SHP files may not always be what you expect. Especially when you import this data and create pipe networks from it, remeber garbage in, garbage out. If the original GIS data has the correct object data associated with it, (inverts, pipe size, materials, etc.) the better end result you are going to get. Additionally you will also need to take into consideration the amount of vertices that these pipe lines have in them. If the pipes have many vertices between actual pipe start and end, Civil 3D will place a null structure at each one of these vertices. This may be acceptable if the pipe really does end there, but edits may need to be made prior to import as well as after the fact.
If the data has excessive amounts of vertices, you can easily edit these with a few different options. First you have the new AutoCAD functions in which you can hover over the vertex and it gives the option to remove the vertex. This is a quick and easy option if you only have a few vertices to address.
Next is the most efficient option, using the Map Cleanup functions of the MAPCLEAN command. The Simplify Objects option will make quick work of the extra vertices. This makes quick work of entire city blocks of pipe data that hase excessive amount of unecessary vertices.
Finally you have the option of using the WEED command, which you may recall using with feature lines, but works with polylines as well. I found this to be the least ideal option, but it is definitely worth having available in case you need it.