Which statement describes a change in route structures due to airline deregulation?

• A. Changed route structures (hub-and-spoke)
• B. Increased direct point-to-point flights
• C. Reduced international services
• D. Centralized maintenance at hubs

Answer: (D)

Deregulation spurred airlines to redesign their networks around centralized hubs to move more traffic efficiently. Centralized maintenance at these hubs fits with that shift because, as routes converge on a few key airports, it makes sense to keep aircraft serviceable in the same locations where they will be flying many legs of the network. This arrangement supports quick turnarounds and coordinated scheduling across a busy hub, which is a practical consequence of a hub-centered route structure.

Other options describe direct outcomes of changing networks in different ways, but centralizing maintenance at hubs specifically reflects the operational setup that enables and sustains a hub-based route system.