OK, then let's start at the beginning.
1.I presume, that Patch 1.01 is installed.
2.You have the Terrain Editor activated.
If that's so, then open the Terrain Editor and Start a new map from a scenario map.
That will create a map in the C:\Users\user\Documents\My Games\Sid Meier's Railroads!\UserMaps directory.
This will give you a map, industries, goods the same what the original scenario had, but not the Cities.
Basically you will have to make a new map of your own design.
The original Scenarios are in the C:\Program Files\2K Games\Firaxis Games\Sid Meier's Railroads!\Assets\XML\_SCENARIOS_
directory and I would not venture to edit them, but you can look them over to see how Firaxis is doing it..
If you have any questions or problems, just let me know. It is not as difficult as it looks at the first glance, all you have to do is to familiarize yourself with the map structure.
....and if you want challenging maps try this
http://www.hookedgamers.com/forums/view ... =42&t=3177 or any of the SAM (Stand Alone Maps) in the Maps section
Jancsika