Running the Route
Once you've installed all the files then the route should be ready to go. When you first load you should be prepared for a bit of a wait - loading from scratch takes about 3.5 minutes on my (SSD-equipped) machine. If you have an old harddrive then it is going to be slowwww.
A couple of the scenarios that start from Kings Cross seem to need the route 'pre-loading' by going into a lighter scenario first - so if a scenario load CTDs then try opening something that you know works before trying it again.
The manual (installed in the Manuals\EN folder as 'Cambridge Lines and the ECML.docx') has lots of information for budding scenario builders including typical traffic in the 50s and how to make the AI do the right thing at key points of the route.
Route Map
The line is 188 miles from Kings Cross to York and 70 miles from Kings Cross to Ely.
If you want to know why I haven't extended it to Edinburgh - well it takes around 13 minutes to save a track change at the moment - doubling the route length (almost) is presumably going to push that time well beyond 20 minutes. Loading a scenario is 3.5 minutes and I expect that with an end-to-end run that would probably go well beyond 5 minutes. TBH does anyone have that level of patience?
Having said that...you never know - perhaps a hardware upgrade (or 128-bit Railworks?) might make it feasible.