An Approach to Incorporating Demand Uncertainty in NAS-Wide Modeling

The Federal Aviation Administration's (FAA's) Operational Evolution Plan (OEP) was initiated in 2000 as a 10-year plan to improve the capacity of the National Airspace System (NAS). MITRE/CAASD has supported the FAA in its assessment of the OEP by using a discrete event simulation of the NAS. Regular performance assessments have provided point estimates of both NAS-wide delays and airport delays. However, the use of point estimates has limited the insight decision-makers have about the amount of uncertainty in the performance estimates of the future NAS. Some level of uncertainty in future performance is driven by uncertainty in future demand levels. Performance assessments have used the FAA's official forecast, the Terminal Area Forecast (TAF), as the basis for determining how much growth to include in future demand. The TAF is an annual publication that forecasts the annual level of operations to be expected at over 3000 NAS airports. The most recent TAF, the 2005 TAF, forecasts yearly operation levels through 2025. TAF traffic level forecasts are based on long-term forecasts of economic and demographic data and are adjusted at the largest airports based on factors particular to the airport.