Dr. Richard de Neufville Massive Uncertainty Dr. Richard de Neufville Professor of Engineering Systems and Civil and Environmental Engineering Massachusetts Institute of Technology Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Massive Uncertainty Objective: To present realistic context of forecasting exercise Topics Evidence Consequences Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Causes of Uncertainty Underlying variability of phenomenon Difficulties in measurement or estimation Unforeseen or “unpredictable” circumstances Limits to valid measurement for example: behavioral patterns Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Evidence 1. Simple Physical Systems 2. Overall Traffic 3. Local Traffic (Worse) 4. Other Operations Airport Systems Planning & Design / RdN

Ratio of Real Costs to Estimated Costs for Airport Projects Costs expressed in constant dollars Median ~= 1.25 Percent of Occurrences Real/Estimated Cost Ratio Airport Systems Planning & Design / RdN

Cost of asphalt rising Local road repairs are likely to lag By Kay Lazar, Globe Correspondent June 8, 2006 http://www.boston.com/news/local/articles/2006/06/08/cost_of_asphalt_rising/ The soaring cost of petroleum -- a primary ingredient of asphalt -- has forced many communities to shoulder a 50 percent increase in costs as crews head out to repave roads this summer. Asphalt sticker shock is creating heartburn for legions of highway chiefs, prompting many to significantly curtail the number of roads they intend to repair this season. And the going may get even tougher. Two major asphalt suppliers for the region are warning of another 50 percent increase by Thanksgiving -- in addition to potential shortages Airport Systems Planning & Design / RdN

Cost Growth for Various Projects 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Ratio of Actual to Estimated Cost DOD60 HWAY WATER BLDNG DOD50 ADHOC MAJOR ENRGY NASA NASA AVG St.Dev. CONST SAT m g Airport Systems Planning & Design / RdN

NASA Projects Cost Growth 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Ratio of Actual to Estimated Cost HST GLL UARS GRO COBE MGL MOBS LSAT EUVE ERBE AVG St.Dev. Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Results of a 2004 study Adapted from: Terminal Area Forecast (TAF) Accuracy Assessment Results Jerome Friedman, MITRE CAASD, Sept. 30, 2004 Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Results of a 2004 study Adapted from: Terminal Area Forecast (TAF) Accuracy Assessment Results Jerome Friedman, MITRE CAASD, Sept. 30, 2004 Airport Systems Planning & Design / RdN

Recent Error Data from U.S Source: MITRE CAASD and FAA Airport Systems Planning & Design / RdN

Recent Error Data from U.S Source: MITRE CAASD and FAA Airport Systems Planning & Design / RdN

Airport Systems Planning & Design / RdN Actual vs. Forecast 10 years earlier Source: FAA Aerospace Forecast FY 2006-2017 Note: These are aggregate NATIONAL data, in which greater local variations tend to cancel each other out Airport Systems Planning & Design / RdN

Older FAA Forecasts vs. Actual Data (% Difference) Review of the FAA 1982 National Airspace System Plan Airport Systems Planning & Design / RdN

Forecast vs. Actual International Pax in Japan Airport Systems Planning & Design / RdN

Forecast vs. Actual International Pax to Japan Airport Systems Planning & Design / RdN

Forecast vs Actual International Pax in Sydney Airport Systems Planning & Design / RdN

ACTIVE GENERAL AVIATION AIRCRAFT 1980 FORECAST Airport Systems Planning & Design / RdN

ACTIVE GENERAL AVIATION AIRCRAFT 1985 FORECAST Airport Systems Planning & Design / RdN

1990 FORECAST ACTIVE GENERAL AVIATION AIRCRAFT Airport Systems Planning & Design / RdN

1998 FORECAST ACTIVE GENERAL AVIATION AIRCRAFT Airport Systems Planning & Design / RdN

Summary and Recommendations Forecast Errors have been large Likely to continue Recommendations: Expensive Forecasting is cost-ineffective Use general trends ...With large ranges Flexible Approach to Planning!!! Airport Systems Planning & Design / RdN