Darkinferno: You probably will see it.

Sadsack: The polycount differs from corridor to corridor. But with all these props included a corridor has something around 30 to 50 thousand triangles. This comes mainly from the cylinders used on pipes and rails. But these polies dont come as a huge mesh. They are split into separate sub meshes around 5 thousand each. So when you look at only a part of the corridor some other parts are out of camera frustum and can be culled. So the GPU often has less to render.
But when you combine many of these corridors to a big level, then you need some more scene management (not only view frustum culling). Maybe it can be done with the new regions or in combination with a basic BSP layout.