If You want to create an imaginary train , then You should have proper knowledge of that Particular Route like Distance , Track MPS, Stoppages,etc....
For e.g. If You want to create a new train between New Delhi & Mumbai.
First Of all You have to decide the category of that imaginary train you are going to create...
then Stoppages of Enroute like some...
more... Major Stations like Sawai Madhopur Jn, Kota Jn , Ratlam Jn , Vadodara Jn & Surat.
When You Update TT of Your IMG then Avg Speed , Distance , Schedule Timings get apprears on Your IMG Train Page.