Difficult to keep assets in Route and not in a Session

I am creating my first Route, but I ended up in having most of my tracks and buildings, etc. in a Session. Now my Route has only a few tracks and buildings. How do I get them back into my Route?

After lots of searches, I got the answer: Merge Session layer into Route layer...

The best way to build your route is to start building, then save. This saves both the route and session. If you open the route for edit a new blank session is created as the route always needs a session in order to run. Your old session is still there unless you overwrite it in someway. Select route and then select session, this loads both the saved route and session. You can now continue with building you route. You can at this point merge the session into the route from the layers tab. This does not put everything into session only the layer so you still need to open the edit session when you start.
The session and session layer are not the same thing.

Merge the session layer into the route layer.

Thank you for the answers

Thank you very much for the help. This is quite a learning curve, and this solution should be quite obvious, I recon.

There is an extensive tutorial on Layers at http://online.ts2009.com/mediaWiki/index.php/How_to_Use_Layers

I've owned Trainz since 2001 and am still utterly confused by Sessions and how hard it is to avoid creating a new one every time I look at a route. I wish we had an option to disable Sessions completely. I resort to going into CM and simply deleting all sessions on a regular basis.

All it requires is a simple change in mindset. Think of the route as the "world" and he session as the "things that change in the world" - like where trains start, where you program them to go.

If you edit a route, then it will create a session, since this is where all the things that change reside (more or less). If you don't want to keep the session for some reason then you will have to delete every time (which is against the whole point really).

If you edit a session, you will never get another one. And while in the session, if you want to edit something permanent such as terrain, then switch to the route layer.

Definitely a mindset, conceptual thing...
I see the route as a container for Fixed assets and the sessions for the variable ones (like consists and schedules, activities, and the like).
Think of the route as being the Stage (Backdrop or Set) and the session items as being the Actors.
Simple as...

Layers in Trainz have been the best thing since sliced bread (and work on the same principle! - jam on one slice, peanut butter on the next)). Sessions add another set of layers (like adding sliced wholemeal bread to sliced white bread).

Of course, anyone who finds the concept too difficult to manage always has the option of placing everything into the route-layer and continuing on from there. But they are missing out on a set of tools that makes route and session creation so much easier.