What about Trainz Maps, or is that not for making realistic maps? I know I was reading about something else that was a Microsoft Tool, and I don't think that it's the one you are talking about JCitron.
Neither... Trainz Maps allowed us to change tracks and signals as well as print out schematic maps of the route in versions up to TRS2009. Microsoft's system is the same as used by Bing and it's their TerraServer project. I'm not aware of any other tool by Microsoft for this. There is Micro Dem if that's what you are looking for. You can generate terrain which can be imported into HOG for export to a Trainz format file.
John