ABSTRACT
Airports facing demand in excess of capacity are now common around the world, especially in North America and Europe. In North America, the predominant means of rationing demand to capacity is through queues and congestion. In Europe and elsewhere, the preferred method of constraining demand is through a slot capacity system. A maximum capacity of the airport is declared, and slots matching this capacity are allocated to airlines. To use the airport at a specic time, an airline must have a slot. The usual objective of this system is to reduce congestion, in the form of delays to aircraft and passengers, to an acceptable level. However, this system is not supposed to eliminate delays entirely, since this would unduly limit the throughput of the airport. Slot limits may also be imposed to reduce environmental externalities, such as noise.
