In recent years, airline flight delays have been among the most vexing problems in the national transportation system. They reached unprecedented levels in 2000, when one flight in four was delayed. Although bad weather has historically been the main cause of delays, a growing reason has been the inability of the nations air transport system to efficiently absorb all of the aircraft trying to use limited airspace or trying to take off or land at busy airports. Recent events most notably the terrorist attacks on buildings in New York City and Washington, D.C., using hijacked airliners, and the economic slowdown that preceded these attacks have changed the extent of the delay problem, at least for the short term. With many airlines cutting their flights by 20 percent or more, the air transport system is having less difficulty absorbing the volume of flights. Whether the volume of flights will continue at these lowered levels is unknown. However, it is likely that a more robust economy and less public apprehension about flying will lead to renewed demands on the air transport system. If so, concerns about delays and the actions being taken to address them may once again command national attention.

Initiatives to address flight delays include adding new runways to accommodate more aircraft and better coordinating efforts to adjust to spring and summer storms. Although most of these efforts were developed separately, the Federal Aviation Administration (FAA) has incorporated many of them into an Operational Evolution Plan (OEP), which is designed to give more focus to these initiatives. FAA acknowledges that the plan is not intended as a final solution to congestion and delay problems. The plan focuses on initiatives that can be implemented within 10 years and generally excludes approaches lacking widespread support across stakeholder groups. The current initiatives, if successful, will add substantial capacity to the nation's air transport system. Even so, these efforts are unlikely to prevent delays from becoming worse unless the reduced traffic levels resulting from the events of September 11 persist. One key reason is that most delay-prone airports have limited ability to increase their capacity, especially by adding new runways--the main capacity-building element of OEP. The air transport system has long-term needs beyond the initiatives now under way. One initiative would add new capacity--not by adding runways to existing capacity-constrained airports, but rather by building entirely new airports or using nearby airports with available capacity. Another would manage and distribute demand within the system's existing capacity. A third would develop other modes of intercity travel, such as, but not limited to, high-speed rail where metropolitan areas are relatively close together. Because of increasing demands on the air transport system or because of the need to meet security and other concerns prompted by the recent terrorist attacks, the federal government will need to assume a central role.

GAO-02-185 National Airspace System: Long-Term Capacity Planning Needed Despite Recent Reduction in Flight Delays