potential objects in railyard model

hi,

i am trying to sell idea of railroad yard object library similar to CT library.
thinking what kind of objects should be developed so that railroad yards could be modeled quickly.

railroad yards are very different from one another. each of them would have classification, receiving, and departure tracks, would use locomotives, perform classification, build, inspection, and receiving. layout differs from one yard to another. intermodal trains have higher priorities.

has anyone put thoughts into it ? what kind of objects could be developed ?
thanks,
Vinay

I like the idea of a library.
An important issue is to be able to create the layout easily and to have a good concept for traveling over the tracks (including track-reservation).
Coupling and decoupling of wagons should be possible.