Kimsanne,
AMTRAK refers to controling where people get towed out off fedspace/stardock to at extern. Figs in all of the MSL's (major space lanes: terra to dock and back, dock to AC and back, dock to Rylos and back, and AC to Rylos and back) get repossesed at extern. However if you surround all the sectors along those routes with figs -- you create tunnels between them. Then when extern occurs and traders are towed they are stuck somewhere along one of those MSL's because they can't be in Fed and can't be moved past a fig'd sector.

This and a lot more is explained in the glossery at http://www.tw-cabal.com.

Hope it helps.

Nod, its a nice tactic if your enemies cloak or sleep in fed overnight, especially if the ships per fedspace sector is low and/or you have a lot of corpies. Makes it easier to get tows that way.