Cutting down runway queues
Most frequent fliers are familiar with long lines at airports: at the check-in counter, the departure gate, and in boarding a booked flight. But 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. Now engineers at MIT have developed a queuing model that predicts how long a plane will wait before takeoff, given weather conditions, runway traffic, and incoming and outgoing flight schedules. The model may help air traffic controllers direct departures more efficiently, minimizing runway congestion. For example, if a controller knows that a plane is unlikely to take off for half an hour, he may choose to keep the plane at the gate to avoid contributing to runway backups. Hamsa Balakrishnan, an associate...