A new end of track railway track. Found under Decor / Misc. Decor and costs 0.
You need Ambitions and to place the package in both the mods/packages (Sims3 ) directory and in the "The Sims 3 Create a World Tool/ Packages" directory for the item to show in your game. There is an earlier post explaining how to install items in CAW.
Importing packages into CAW
Make sure that the XYZ co-ordinates match the end of track to the straight track.