The Train Collection is a Collection in CityVille that contains items which can be acquired by clicking on your Friends' wall post that asks for help with the stops, when they send Trains. Turning in this collection gives you a Grain Elevator in your inventory.

There is also a chance of acquiring these collectibles by putting them on your wishlist and either opening a Mystery Gift or clicking a neighbor's train wall post.

Collectibles					Trade in Reward
Conductor Hat	Railroad Crossing	Railroad Sign	Tracks	Whistle Toy	Grain Elevator	100 Goods