Tobias is trying to mentally adapt to the fact that Amar is alive while Tris examines the photo of her mother that Zoe gave her.
The scenery zips by: trees, birds, pavement. Tobias observes: "This is a wild world." Oh baby, baby, it is a wild world.
The truck takes the gang through a few fences and into the Bureau of Genetic Welfare, which is in what used to be O'Hare Airport.
Zoe explains what an airport was: a place where travelers waited an interminable amount of time for constantly delayed airplanes, which were a form of air travel that would be fast and efficient if the airlines would just get their stuff together and be honest about basic things like airfares and travel times.
Actually, Zoe says it's "safe, fast, and amazing" (14.38), leaving out a few critical details…
The airport is now used to "monitor the experiments" (14.42) from a distance. And by "experiments," Zoe means all the people, like Tris and her family and friends, who live inside the city.
The people at the Bureau actually still use the scanners, and everyone has to go through them.
After submitting to a full-body scan, everyone follows Zoe into a huge control room, where a man named David appears and says, "This […] is what we've waited for since the very beginning" (14.71). What? Frequent flyer miles with no blackout dates?