Construct your bridge, select all the brushes/curves, save as a new .map file, go into that .map file and make sure the thing is centered at 0, 0, 0 on the grid. ( Best to align an edge, or the exact center of the mass), and then compile/convert it to an .ase. That way you can now use the bridge as a misc_model and rotate as needed. If you don't know how to make an ASE, you could follow this tutorial. http://jkhub.org/tutorials/article/67-making-ase-models-with-gtkradiant/ Q3map2 GUI also has some presets for making an ase.