Radar Fence

The Radar Fence is a barrier created by the Think Tank

Background
Created by Doctor Borous to prevent the Think Tank and any creature without a brain from escaping into the wasteland.

Gameplay
If anyone without a brain wanders outside the perimeter of the fence, it will result in being automatically teleported back inside the perimeter, so it will prevent the Courier from leaving the Big MT until they finish the Old World Blues main questline.

Appearances
The Radar Fence appears

Behind the scenes
The Radar Fence pylons have an unused effect associated with them called. It is a blue halo-like light that was supposed to spin around the top of the pylons.