MOST FREQUENT FLIERS are familiar with long lines at airports: at the check-in counter, the departure gate, and in boarding a booked flight. Yet, even after passengers are buckled in, the waiting may continue- when a plane leaves the gate, only to sit on the tarmac, joining a long queue of flights awaiting takeoff. Such runway congestion can keep a plane idling for an hour or more, burning unnecessary fuel.
展开▼
