What does "You can't get there from here" mean for people who live in Pittsburgh?

Question

I remember reading this as a driving tip for tourists visiting Pittsburgh, but I really have no clue for its meaning. Now as I am going to Pittsburgh, I'd like to know.

Answer 1

never heard of living there but maybe because of all the mazes and bridges that you have to go through

Answer 2

idk but i'm from pittsburgh (:

Answer 3

when i lived in maine, i heard this more than once (in that stephen king/salem's lot accent). i think it means that it's so backwoods, there aren't any roads to it. but i really have no idea how it would relate to pittsburgh.