When they are loading the bus for the trip that begins in Midtown Manhattan, the bus is parked near a bus terminal. The only bus terminal in Midtown Manhattan is Port Authority Bus Terminal. The terminal used in the movie is not the Port Authority Bus Terminal.
At the very end, just before the the bus splits, they are supposedly heading into Denver. However, for just a moment before the "Denver 25 mi" sign, you can see a California state highway sign for CA2, the Angeles Crest Highway, north east of LA.