Unable to set PPOs on bridge?

[delems]

How come can't set PPOs on bridge?

[TR6AL]

PPO's can only be set on terrain tiles and bridges are not part of the terrain tile.. 

[delems]

Hmm, ok.

Maybe PPOs need to be able to be set on more than just terrain tiles?

[TR6AL]

Can't do it .. engine limitations .  If we could I would have been stacking all sorts of things 

The only thing that resembles a bridge that can have PPo's placed on it is the overpass , as its part of the terrain tile .