Hello I am a Trainz novice and I was thinking about creating my own fictional Trainz route that runs through Wales. I want it to be on a large scale and have a few mainlines (with terminus's either end) and many branch, metro and commuter lines. I have OCD (It does bare relevance) and as such my line HAS to have a realistic History and back ground story and this is where I am stuck. Because How and where can I fit a large scale Railway in Wales. I don't mind alt history but I do want my own towns and cities so just re mapping Wales is not only time consuming but also not what Im looking for. I want trainz in My Livery (Llinellau Ddraig) to operate the route as well and I want it to be set in modern day. I dont care how long it takes to build I have a feeling that with my train enthusiasm ill manage

even if its not best quality. Any help would be very much appreciated. Thank You.
Owen,
You've already started in the right direction with your back history. This will ensure that your route project remains one that you'll look forward to working on for years to come. Now, before you start here are some things that have helped me with my big route project.
Having that back history is one of the most helpful things you can have. One of the things that's helpful is to look into the real railroads in the region and build on that. Take a small branch line and make that the main company now. Perhaps the rail line was originally built by a small group of businessmen to haul coal from one town to a connection with a bigger railroad. As time went on, the company grew, but was absorbed into the bigger rail line. Fast forward to now and the big company was going abandon not only the little branch but also their whole line. Instead of ripping up the tracks, the Crown or county government, through a petition sent up from the local communities and business people, decides instead to keep the line operating. A new small company is named the designated operator of the county-owned railway, and now operates not just the original branch but also the mainline too.
That scenario has played out many times over here in the US. Up here where I live in New England, the Maine Eastern, for example, took over a former Maine Central branch that was going to be abandoned. Initially, they operated only a small portion, but today they operate many more miles and are rebuilding the lost business on the line which is actually owned by the state of Maine government.
Now, before you dive right in and start building, you also need to look at the terrain, cities and towns. I suggest reading over many, many maps, photos, ordinance maps, and maybe even investing in a program called TransDEM. TransDEM, which is available here:
http://www.rolandziegler.de/StreckeUndLandschaft/startseiteTransDEMEngl.htm. This program allows you to build realistic digitally-imaged from satellites landscapes based on the real thing. How cool is that. The cost is minimal, with a bit of a learning curve, but the investment is worth it.
Now, you've got your purpose and your terrain. What about those cities and industries? Towns and cities will grow up around the industries. Being Wales, you have coal, slate, iron, wool, and textiles. The bigger cities will of course follow the bigger industries and so forth. Now this brings us to an important point I want to make regarding Trainz. Trainz is great, don't get me wrong, with all the nifty buildings and other content. The problem is Surveyor will let you place hundreds, if not thousands, upon thousands of little objects ranging from trees to manhole covers if you want. This is no reflection on you, it's the nature of the beast, and all of us route builders have been bitten by this trap. The problem is when you go to run the route in Driver, nothing will move or it will move very poorly as the Driver module tries to load the information from disk to memory to make the AI drivers move.
So having said this, the best way to mitigate the problem, which isn't solved completely, but it's better, is to keep the object numbers down a bit. You can build cities, don't think you can't, just don't go hog wild and build the complete city with blocks upon blocks of buildings. Instead keep the structures closest to the industries and termini with perhaps a block or two of row houses and other houses and buildings to give the look and feel of a bigger place. This really is no different than a movie set where the set builders only have a few buildings and a backdrop to represent the rest. Using sight-blockers such as bigger buildings, trees, and even fences, the scene can be really busy, but not very deep with buildings at the same time. Believe me, we've all be guilty of wanting to completely build a full city.
You mentioned names and locations. This too takes looking at the maps. Take cities and towns and move them around. I did this on my own route, which is nearly 10 years old now. I'm modeling a representation of my area. I've taken cities and towns and moved them around. I chose the names because I liked them and saw them on a map. Leominster, which is a fairly big city near Fitchburg in real life becomes a smaller town on my route. The opposite is for Wareham and Acton. In reality, both of which are smaller towns, with Acton being a tiny bedroom community. On my route, Acton is now a bigger city with a large freight yard, and Wareham is now a big textile city with lots of mills, set in the distance to hide the baseboard edge, a big rail junction, and a bunch of branches. The other kick is both towns, sic cities, are close together on my route, where as in reality, they are 40 miles from each other.
Anyway. There is one other important point that I think is worth mentioning. Keep in mind that this won't all happen in one day. You can build feverishly, yet barely scratch the surface. Keep in mind that quality route building takes time and that level of satisfaction will never be there if the details aren't right. When you feel tired from the drudgery of route building, go off and do something else. Go out and collect photos of the region, maybe even run someone else's route. This will get you up for air so you can start creating again.
John