I've played this game for 1200 hours and I STILL don't understand how everyone seems to know which section of each map is in what order.
What do you mean? Dustbowl progresses in a set order. Dustbowl 3 is the final stage and he's referring to the bridge over the trench to the final capture point (under the big missile). As far as I know, only Hydro and Dustbowl have any sort of progression like this, but I could be wrong.