Why didn't they use the same pass?

[O'Boile]

well the only reason the fellowship escaped from moria was because the orcs got scared away by the balrog

This is the book forum, not the movie forum, so don't use the movie as a reference. The orcs did not run away in the real story.

I vaugely remember Gandalf saying that it would take to long to go that route. I also seem to remember him saying it would be too close to Dol Gulder. Also, it was winter time, so those passes (which were further north) could have been even worse that Carahdras (SP?).