Precipice Passage - The roads only lead in a single line (at least from what I've saw), and most of them go through mountain passages, and they're pretty steep and big mountains.
Ropa/гора River - Ropa/гора (I can't find a phonetic translator, sorry), is Russian for "mountain", and, well, a river cuts through quite a lot of the map, and I do believe (at least according to a lot of people at CG), that C45 is somewhere in Russia, if not very near it.
Route Forty-Five - Big roads going through the map, and we are outside ol' City Forty-Five, so, Route Forty-Five? (See what I did there?(If not, it's a play on those American roads, because we're outside City Forty-Five, Route Forty-Five, yeah, you know?))