Hello Mac,
The Bath to Templecombe route is one of the default layouts that came with the game, in essence, and in all honesty, all of the default routes were a bit of a hotchpotch utilising the default crappy trees and other scenic items that were only available when the game was originally released. However, now that various other scenery content has been created in the last 18 months, or, so, I've been able to adorn all of my default routes to bring them up to a higher standard by my own personal touches. The 6 best default routes in my opinion were York to Newcastle, London Paddington to Oxford and the Barstow to San Bernardino California, routes, along with the 2 German layouts Hagen - Siegen and Seebergbahn, as I love European trains. These were the longest layouts offering both freight and passenger train combinations, and you can use steam as well as diesel locomotives. On the German routes you can also utilise the newer German and Spanish steam locomotives, and of course the various electric locomotives and rolling stock now produced. The Castle Rock route was set in Denver, Colorado, this has also now been used by the Spanish and Chinese modellers who have released their own versions of this small route with Spanish and Chinese scenic items to match. We have a few Trainzy friends that have created content for the game, The Spanish on
http://www.trensim.com/, Gor, also from Spain who has created a fantastic narrow guage route, some of the Russians, Iceman from Germany
http://rail-sim.de/railsimnew/index.php/downloads and Josef Korecs from the Czech Republic, along with a few others, we now have a lot more trees, bushes, houses, apartment blocks, warehouses and factories, railway buildings, cars and other road vehicles, signals, level crossing structures, animated people for our station platforms, etc, etc, to place on our maps. Jointed Rail from America made some GP38-2 diesel locos that you can freely obtain from their site and there are now some reskinners who have jumped onto the bandwagon to offer us more variety from the various Railroad companies from the present as well as some "fallen flag" variants from companies that no longer operate. These are being generated on a fairly regular basis, and with the advent of a couple of other layouts, such as the Altenburg to Wildau, a true freeware route set in Germany by a Dutch creator called Siegfried A.Derks, who has made a lot of his own scenery assets for his layout, this obviously gives you more items to utilise on other routes as you see fit. His blogsite is here, he will be releasing an up to date version of his map soon that he continues to expand.
http://sad-railworks.blogspot.com/
As with all 3rd party creators you have to visit various sites to obtain new content. It obviously depends on what you personally like to play with, for freebie American content then you can visit
http://railworksamerica.com/
My 2 personal favourite layouts are Burlington Northern Big Horn Sub Division and the Bay of Quinte, but, have a look at the others which are both small and extremely large and subsequently have a lot of freebie assets to go with them. Obviously the standard differs from creator to creator, only you can decide which are the best to play on, some of them have lots of scenarios for each route, others may have just put 1 or 2 in.
You can also have a look in the file library at
http://www.trainsim.com/ for lots and lots of other freeware content.
For British content you need to go into the UKTS library, it's the equivalent of the DLS
http://uktrainsim.com//index2.php
On here are many routes for both steam and diesel, our lovely friend Big Vern Moorhouse has a couple of layouts, Heartbeat Moor (North Yorkshire Moors Railway) and the Sulitjelma Railway, which are extremely suitable for steam, coupled along with some other routes, The Port Road version 3, Leafy Suburbs version 2, the Crouch Valley Branchline, Aln Valley Railway version 1, Blyth & Tyne and
South Devon Banks version 12, these are some of my personal favourites, you might not like them, but, until you view them only you can decide.
I almost forgot to say, but, a lot of freeware routes use Payware routes as a template (the Isle of Wight add-on), is an example, you might see this layout mentioned in the various "Read Me" documents enclosed with each layout, this has narrow guage tracks and lots of scenic assets that creators have used on their own creations, and as such is recommended you obtain to get the full value of the freebie layouts that utilise it.
Unfortunately, there does seem to be more Payware stuff around then freeware, but, if you don't obtain this then you won't be able to play with the newer routes as many of the creators have utilised the newer tracks, overhead electric gantries, etc, etc, on their creations. But, there is some freeware about it just needs a bit of time to explore around and see what you might think is suitable.
Give us a shout if you require anything else, I can give anyone a shopping list of websites to visit for both free stuff and Payware material, it all depends on what you all like to play with.
Cheerz. Steve. :wave: