Why do planes take so long to taxi?

The creep in taxi times is attributed to a series of changes: massive runway construction projects at some of the nation’s busiest airports; schedule changes that increase the number of flights at peak hours; and new, distant runways that relieve congestion but require more time to reach.

How are airport runways oriented?

All runways are numbered based on the magnetic azimuth (compass bearing) in which a runway is oriented. So if you’re on runway 9, then you’re heading east (90 degrees on a compass). Runway 36 means you’re moving north, and so on. Most runways can typically be used in either direction, depending on prevailing winds.

Why do airports have two runways in one direction?

A very important reason is to provide an alternative runway to align with the wind. If the airport only had parallel runways in one direction, the runways could be subject to cross-wind landings and severe cross-wind landings can be very hazardous.

Why do runways have thresholds?

All runways in big airports, even those covered in asphalt, have reinforced concrete foundations that vary in depth. They’re deepest where the touchdown zones are located, shallower elsewhere. That’s why runway extensions usually just add extra takeoff distance, but the landing zones remain the same, creating a displaced threshold.

Why is taxiing distance reduced between runways?

The reduction in taxiing distance, however, is based on the premise that one runway is to be used exclusively for takeoff and the other for landing. In this case the terminal buildings are located between the runways so that the taxiing distance for each type of operation (takeoff or landing) is minimized.

Should all airports have parallel runways?

Having only parallel runways is also not necessarily the best for traffic. In some cases, major airports will have their primary commercial traffic landing on parallel runways and will divert smaller and slower general aviation aircraft to other runways to avoid congestion on the parallel runways.