As an experienced route builder, I'd like to add my few points too.
First of all I agree with the other people here. Start off slowly and gain some track-laying and landscaping exerience. When I first started, I downloaded some of the really super AAAAA+++ routes by the GFisher and many other experienced route builders. I opened them, modified them, and learned many of their procedures for track laying, signal placement, texturing, etc.
There's nothing wrong with building a small or large model railroad-type layout. These can be fun to build and a lot of fun to drive. However, since most model railroads are small, you don't want so much content in a tiny area that your computer hardware glows bright red and your system performance drops to that of a '286 (I'm kidding about the glowing part, of course!) A large model railroad too has the same inherent issues, in addition to its larger size. Most large model railroads I've seen are usually jam packed with random bits of different scenes that don't always appear to be connected consistently.
These issues can also be a problem when building a large realistic route, and this requires a lot of planning and the bigger it grows, the more work it is to test. My current route is about 150 miles long now. I started it back in early 2005 and it has gone through a couple of revisions since then. When testing, it can take a whole day or more to go through a session as I drive along looking for trackside errors such as floating roads (I really hate that), misplaced objects, errant track direction markers, even bad track joins, which the AI drivers will warn rather generically about. You'll find that even testing a small route requires multiple switches between Surveyor and Driver as you find things to fix and then continue on your way along the lines.
Once that section is "completed", I will move on to the next, which can be nothing more than a baseboard or two more. In the process of building my route, I have also merged other peoples routes and connected them to mine. This process causes a whole new enigma as industry-enabled tracks disconnect from the line that feeds them. There are other things too such as matching heights, textures, trees, roads, etc. so they blend into the rest of the route in such a way so that it appears that this is one continuous landscape when in driver mode.
Now when building a route, whether it's a model, a ficticious route, a representation of a shortline, or section of a Class 1, you need to keep in mind the purpose for the original. The late John Armstrong (1920 - 2004) mentions this in his books on model railroad layout design. One of his recommended boosk is "Track Plans for Realistic Operation", available from Amazon.com, is a good read for information on this. To set a purpose for your route, come with a story about the industries, the railroad companies, the geography, time period, etc. In the real world, a railroad doesn't run for the fun of it, unless of course it's owned by a wealthy person who owns 1:1 scale trains and the trackage to run them on. This will yarn that you weave will give your railroad more meaning as you build from one city or town to another, and connect one industry to another.
This will also help with another point I am going to make. Consistentcy. You want your railroad to be consistent all the way from point A to point B. The landscape can vary, but you don't want huge mountains next to a big city, or ancient cities next to a modern one with modern steel mills in the middle of them. There's no one stopping you from doing this, but in reality it kind of looks stupid. With the consistentcy factor, this will keep you on-track with a particular plan, your yards will look a lot better, and your industries and cities served by the railroad will fit into place.
One of the biggest helps in layout and building a route, is reading, research, and observation. If you can, look up online topgraphic maps. Topozone is one excellent place.
www.topozone.com Microsoft's Bing and Google Earth are also good for looking at fairly current satellite and isometric views of various places. Bing has the Bird's Eye view for many areas of the US and Canada. With this feature, you can view freight yards, streets, mainlines, etc. in enough detail to even see people on the street. Now you may not be building a realistic route, but it's still good to look at the maps and reasearch industries. This will give you track-layout ideas and the industry-types will give you a heads-up when planning on freight service.
Another important aspect of route building is having fun. When the process becomes a chore, move on to something else such as driving other peoples routes, or even your own, map reading, and just plain going out and away from the computer. I find that I go through spurts where I will build like crazy then dry out. During the dry periods, I'll make observations about areas that I travel in. Recently, for example, I saw a nice looking industrial park. I'm not sure if there was rail service or not, but I made a nice fascimile of the park and I added in a loop track to serve the warehouses and industries. In my industrial park, there are some warehouses and some smaller industries that require rail service. There are a couple of plastics companies, a food distribution warehouse, and a lumber yard. All of these require service of some kind. The area as I remembered it also had some retial stores like a WalMart and others so I added in a couple of shopping plaza-like places and a couple of malls and restaurants.
And finally the most important thing is
Backup your route! Please, oh, please back it up and make multiple copies of your backup. There will be long periods of building and things happen to computers. You don't want your efforts to end up in bit heaven, or wherever they go when something happens to data.
Anyway, there's a lot of information here, and I'm sure the others here will have more to say.
John
I hope to have 2 fairly large cities, a rural village, maybe with a narrow gauge line connecting to a nearby lake, a mountain pass, and some American Midwest style countryside. Some thing I would like to know are:
