This Report can be found on the FAA Web Site: http://www.faa.gov/arp/publications/reports/index.cfm
 

Office of the Administrator 800 Independence Ave., SW. 

Washington, DC 20591 

 

June 2004 

You are about to read a study that takes a new approach to assessing our 

country’s future needs for airport capacity. This study looks at population 

trends, economic and societal shifts, and the changing dynamics of the airline 

industry. It compares that data with planned infrastructure improvements at 

our airports and projects where future capacity constraints will occur. 

The time is right to do this. The aviation industry is going through a difficult 

period. The blows that hit the U.S. economy so hard after 9-11 landed 

squarely on the back of the aviation industry. But more passengers are 

returning to the air. Nine of our 35 major airports are operating above 

9-11 levels. And by the end of 2004, we expect a return to pre-9-11 operating 

levels at 15 major airports, including seven of the top ten. 

So, what does the future hold? The changes are clear and profound. Starting 

before 9-11, and accelerating since then, business travelers are revisiting their 

travel needs and choices. Demand for low-fare service is strong and growing 

stronger. The internet has led to price transparency that today allows 

consumers to “shop around” and compare prices for competing carriers in 

minutes. Fractional ownership is also offering business travelers new options. 

And smaller aircraft are promising travelers greater schedule and destination 

choices. 

Our data indicate that many existing airports will need to be expanded to meet 

future demand, and in a few instances, new airports will need to be pursued to 

meet growth challenges. The metropolitan areas that have traditionally driven 

aviation demand will continue to do so, but new metropolitan areas in the 

South and Southwest are emerging as needing critical capacity as well. And 

unfortunately, we have metropolitan areas on both coasts where demand will 

outstrip capacity without adequate solutions in sight. 

The Government’s most significant and challenging role in this dynamic 

environment is to examine where the requirements are and to work for the 

development of the infrastructure and capacity to accommodate whatever level 

and type of demand the market may bring. Since the summer of 2000, when 

congestion choked the system, airport owners have poured a lot of concrete, 
2 

added new runways, and made solid progress in expanding this Nation’s 

physical infrastructure. Our program of strategic investments under the 

Operational Evolution Plan (OEP) is intended to keep pace with demand over 

the next decade. The OEP is a 10-year plan to increase the capacity and

efficiency of the National Airspace System. It focuses on infrastructure --

primarily new runways -- and technological and procedural initiatives at the 

top 35 airports. 

The Department of Transportation, under the leadership of Secretary Mineta, 

wants to ensure that the long-term capacity of the aviation system matches 

forecasts of demand. This study asks: 

• Which of the 35 OEP airports will be able to meet future demand 

and which will not and why? 

• Besides the 35 OEP airports, will there be other geographic areas 

of the country unable to accommodate demand for air 

transportation? 

Our study looks further into the future and takes a different approach than we 

have before by comparing demand and capacity levels not only at airports, but 

in metropolitan areas as well to determine where future capacity constraints 

may emerge. This will underscore the importance of continuing the 

investment plans now in place in order to be ready for future airport capacity 

demands. We do this with the conviction that if we provide accurate data and 

credible forecasts, communities around the country will step up to the plate. 

They need to help make sure they have a dynamic place in our aviation 

system -- one that provides such vital support for our Nation’s economy and 

social fabric. 

Marion C. Blakey 

Administrator 
CONTENTS

EXECUTIVE SUMMARY........................................................................................................I

PURPOSE......................................................................................................................................I

Overview of Methodology.......................................................................................................I

Top 35 airports...................................................................................................................II

Other airports ....................................................................................................................III

Socio-economic demand modeling...................................................................................III

Capacity modeling ............................................................................................................III

Findings in Brief ................................................................................................................. IV

General............................................................................................................................. IV

Capacity needs in 2003 .................................................................................................... IV

Capacity needs in 2013 ......................................................................................................V

Capacity needs in 2020 .................................................................................................... VI

Other Airports with Capacity or Delay Constraints that Warrant Further Action ........ VIII

A System in Transition ........................................................................................................ IX

Conclusions.......................................................................................................................... IX

CAPACITY NEEDS IN THE NATIONAL AIRSPACE SYSTEM REPORT .................................. 1

PURPOSE......................................................................................................................................1

Coordination With Affected Airports.....................................................................................3

Findings of the Study .............................................................................................................3

Capacity Needs in 2003 ......................................................................................................4

Capacity Needs in 2013 ......................................................................................................5

Capacity Needs in 2020 ......................................................................................................8

A System in Transition .........................................................................................................12

Scope and Methodology........................................................................................................12

Top 35 airports..................................................................................................................13

Other airports ....................................................................................................................14

Socio-economic demand modeling...................................................................................14

Capacity modeling ............................................................................................................15

Conclusions...........................................................................................................................15

APPENDIX A: LOCATION IDENTIFIERS........................................................................... 17

APPENDIX B: METROPOLITAN AREAS AND ASSOCIATED AIRPORTS............................. 19

APPENDIX C: SCOPE AND METHODOLOGY..................................................................... 21

MODELING CURRENT AND FUTURE AIRPORT CAPACITY .....................................................21

Modeling Current Capacity..................................................................................................21

Modeling Future Capacity.................................................................................................22

Incorporating Operational Constraints..............................................................................23

MODELING FUTURE AIRPORT DEMAND.................................................................................24

PROCESS OF IDENTIFYING AIRPORTS NEEDING ADDITIONAL CAPACITY ...........................26

Estimating Future Performance ..........................................................................................26

i
SELECTION CRITERIA FOR IDENTIFYING CAPACITY CONSTRAINED AIRPORTS.................28

Top 35 airports..................................................................................................................28

Other Airports...................................................................................................................29

PROCESS OF IDENTIFYING METROPOLITAN AREAS NEEDING ADDITIONAL CAPACITY ....29

Estimating Future Performance..........................................................................................29

Selection Criteria for Identifying Capacity Constrained Metropolitan Areas ...................30

APPENDIX D: THE EFFECT OF THE SENSITIVITY ANALYSIS USING THE FY 2003 

TERMINAL AREA FORECAST.................................................................... 31

Preliminary Evaluation of Changes to the 2013 Results....................................................34

Summary of Potential Changes to 2013 Results...............................................................35

Preliminary Evaluation of Changes to the 2020 Results....................................................36

Summary of Potential Changes to 2020 Results...............................................................37

LIST OF FIGURES AND TABLES

Figure 1. Airports and Metro Areas that Need Additional Capacity in 2003 .................................5

Figure 2. Airport and Metro Areas that Need Additional Capacity in 2013 

(After Assumed Improvements) ............................................................................6

Figure 3. Airports that Need Additional Capacity in 2013 

(If Planned Improvements Do Not Occur).............................................................8

Figure 4. Airport and Metro Areas that Need Additional Capacity in 2020 

(After Assumed Improvements) ............................................................................9

Figure 5. Airports that Need Additional Capacity in 2020 

(If Planned Improvements Do Not Occur)...........................................................11

Table D-1. Summary of Forecast Differences: 2002 TAF and 2003 TAF ...................................32

Figure D-2. 2013: Potential Change in Analysis Results Using 2003 TAF 

(If Planned Improvements Do Not Occur)...........................................................35

Table D-2. Summary of Potential Changes to 2013 Results.........................................................35

Figure D-3. 2020: Potential Change in Analysis Results Using 2003 TAF 

(After Assumed Improvements) ..........................................................................36

Figure D-4. 2020: Potential Change in Analysis Results Using 2003 TAF 

(If Planned Improvements Do Not Occur)...........................................................37

Table D-3. Summary of Potential Changes to 2020 Results.........................................................37

ii
Executive Summary 

Purpose 

This study was undertaken because the Federal Aviation Administration wanted to assure 

that the long-term capacity of the aviation system matched forecasts of demand. It is 

important to look not only at individual airports in the longer term, but also at the 

infrastructure of the airport network to ensure sufficient capacity to meet that demand. 

To that end, two basic questions were asked by the FAA: 

• Which of the 35 Operational Evolution Plan (OEP) airports will be able to meet 

future demand and which will not and why? 

• Besides the 35 OEP airports, will there be other geographic areas of the country 

unable to accommodate demand for air transportation?

The OEP is a 10-year plan to increase the capacity and efficiency of the National 

Airspace System. It focuses on infrastructure - - primarily new runways - - and 

technological and procedural initiatives. The first OEP report was issued in December of 

2001. It is published annually. It focuses on 35 of the busiest US airports (the 31 large 

hubs plus MEM, CLE, DCA, and PDX). It is divided into four core problem areas: 

airport weather condition, en route severe weather, en route congestion, and 

arrival/departure rate. FAA’s Airports organization determines when a proposed runway 

is ready for inclusion in the OEP and monitors its progress with support from the Air 

Traffic, System Capacity, and Region and Center Operations organizations in the FAA. 

A new runway at an OEP airport is added when we are reasonably certain of its 

alignment, schedule, configuration, and planned use. 

In March 2003, a team was assembled to develop answers to these questions. The team, 

led by the Airports organization (ARP), and including representatives of the Air Traffic 

Organization (ATO) and the MITRE Corporation’s Center for Advanced Aviation 

System Development (CAASD), began the Future Airport Capacity Task (FACT), an 

assessment of the future capacity of the nation’s airports and metropolitan areas. 

Overview of Methodology

There have been several well-documented studies to evaluate airfield capacity at the 

busiest 35 airports. The purpose of the FACT effort is to bring these studies together in 

order to develop a common list of airports (or associated metropolitan areas) that may 

need additional capacity. Bringing these studies together required extensive amounts of 

information to ensure consistency among them, including information on: 

• current operations 

• current capacity at individual airports 

• how operations may change in the future 

• how new technologies and runways will contribute to increasing airport capacity 

I
• what demand levels are likely to exist in the future

• where that demand is most likely to occur. 

Once this information was gathered it was possible to perform the necessary analyses to 

identify where additional capacity may be necessary. 

Top 35 airports 

The initial focus of this effort concentrated on the 35 airports currently tracked as part of 

the OEP. To be identified on the common list of airports it was necessary for these 

airports to satisfy the criteria of each individual study, under two different future traffic 

level assumptions: one using the 2002 Terminal Area Forecast (TAF) and the other using 

demand estimates produced by CAASD’s experimental model of origin and destination 

(O&D) traffic (a total of six criteria). If any of the criteria was not met in either future

demand scenario, then an airport was not included on the common list. Because the 

requirement for commonality was so strict, the results of this assessment should be 

viewed as a minimal list of airports needing additional future capacity. The specific 

criteria used for each individual study are described below: 

• Annual Service Volume (ASV): The annual level of traffic that results in a 

given level of average delay, known as ASV, was calculated as part of the 

capacity assessment used in this analysis. ASV considers multiple runway 

configurations and utilizes an annual estimation of weather conditions for each 

configuration in its calculation. A ratio of annual demand to ASV estimated at 

0.8 or above (demand at least 80% of capacity) was an indication that an airport 

may need additional capacity. 

• NAS-wide simulation of airport arrival delay: Another way of estimating the 

future performance of airports is by using a simulation model to estimate future 

levels of delay. Capacity information is combined with traffic information and 

used as inputs to a simulation model. The model then calculates average delay for 

individual airports. High levels of delay indicate a potential need for additional 

capacity while lower levels of delay could indicate adequate capacity to meet 

demand expectations. For the purpose of this analysis, average arrival delay 

estimated at 12 minutes per flight or above was an indication that an airport may 

need additional capacity.

• Extrapolation of historical data: A third way to estimate future performance is 

to use historical data to extrapolate potential changes in performance while 

accounting for changing levels of demand and capacity. Using the FAA’s 

Aviation System Performance Metrics (ASPM) database, “Airborne Delay” was 

used as an estimate of the arrival delay due to capacity at the airport, and “Taxi 

Out Delay” was used as a measure of airport-related departure delay. Also 

calculated was the ratio of annual traffic to an annualized capacity at each airport 

(based upon hourly airport capacities in VMC, MMC, and IMC). If the 

extrapolated delay was estimated to exceed 4.5 minutes per flight or the 

demand/capacity ratio was 0.95 or above, that was an indication that an airport 

may need additional capacity. 

II
Recall that each of these criteria needed to be satisfied under each traffic level 

assumption. Requiring the criteria to be met using the two different traffic levels 

provided some level of sensitivity analyses around the results. 

Other airports 

This analysis was later expanded to include 291 commercial service airports across the 

country, including an analysis of capacity in 223 metropolitan areas. The reason for 

expanding the list beyond the top 35 airports was to approach the question of which 

airports and metropolitan areas may need additional capacity in the future. The 

information available about, and the knowledge of, the top 35 airports was much more 

extensive than the information about these other airports. Because of this, the criteria 

used in this assessment for the top 35 airports were much more stringent than the criteria 

for the other airports. For airports beyond the top 35, a simple analysis of annual demand 

versus annualized capacity was performed. If the predicted demand was expected to be 

at least 90% of the available capacity, that was an indication that an airport may need 

additional capacity. As more detailed modeling is done in the future, a set of criteria 

similar to that used for the top 35 airports will be utilized. 

Socio-economic demand modeling 

The principal forecast of future operations was the 2002 TAF. For the OEP 35 airports, 

the TAF makes projections of future enplanements and operations on an airport-byairport basis based upon the economic and demographic characteristics of the airport 

metropolitan area. As a secondary source of information, this analysis also considered 

demand estimates produced by CAASD’s experimental model of origin and destination 

(O&D) traffic. Similar to the TAF, this model produces forecasts of demand based upon 

the economic and demographic trends. Unlike the TAF though, the model produces 

forecasts of traffic for individual pairs of origin and destination metropolitan areas. 

Socio-economic trend information, including changes in demographics, income, market 

power, and other factors, were considered as part of this analysis. Passenger demand was 

estimated as originating in, or traveling to, a metropolitan area rather than a specific 

airport. This passenger demand was then translated into airport operations through a 

route selection process (direct or via a third airport) and by determining the correct 

aircraft fleet necessary to handle the passenger traffic. This additional estimate of future 

traffic levels was then utilized as part of the demand/capacity analysis. 

Capacity modeling 

Three years were selected for analysis: 2003 was used as the present-day baseline; 2013 

was chosen because it is the last year covered by version 5 of the OEP; and 2020, because 

it was the time horizon of the 2002 TAF. The 2013 evaluation assumed that all new 

runways and procedural improvements outlined in the FAA’s Operational Evolution Plan 

(OEP), version 5.0 would be implemented at the top 35 airports. For the 2020 capacity 

assessment, all active plans for additional runways and airport reconfigurations were 

taken into account. Also included were optimistic assumptions about future technology 

and procedures at the top 35 airports. These assumptions were based on various research 

III
proposals and extrapolations from the latest OEP because there is no similar report that 

would indicate likely capacity improvements by 2020. 

Findings in Brief

General 

• As air traffic levels continue to grow over time, it is well known that the 

additional demands placed upon the NAS will strain the system’s capacity. 

However, the FACT analysis shows that even today there are areas in the NAS 

where additional capacity is needed, and these needs will grow even stronger as 

traffic levels continue to increase. Based upon this study, it is expected that 

approximately 5 percent of the nearly 300 airports analyzed will require 

additional capacity by either 2013 or 2020. 

• This study indicates that airports other than the top 35 tracked by the FAA’s 

current OEP will potentially need additional capacity in the future. As more 

detailed studies are performed at those airports, it may be shown that they warrant 

inclusion in the OEP to better track planned improvements over time. 

• Growth trends will continue to affect many of the same metropolitan areas that 

historically have had a need for additional capacity. This study indicates that the 

predominant trend over the next two decades largely will be the expansion of 

existing airports to meet forecast demand. At the same time, new metropolitan 

areas have emerged as needing additional capacity in the future. These 

metropolitan areas are mostly in the south and southwest. Increases in air traffic 

congestion in some metropolitan areas, however, may lead to the establishment of 

new supplemental airports such as the proposed Ivanpah airport near Las Vegas, 

NV and the proposed South Suburban Airport near Chicago, IL. (A replacement 

airport at San Diego, CA may also be a possibility.) 

Capacity needs in 2003 

The FACT analysis identified five airports where additional capacity is necessary today 

(see Figure ES-1): 

• Hartsfield-Jackson Atlanta International (ATL) 

• Newark Liberty International (EWR) 

• New York LaGuardia (LGA) 

• Chicago O’Hare International (ORD) 

• Philadelphia International (PHL). 

In addition to these airports, the Atlanta metropolitan area was also identified as needing 

additional capacity. The Atlanta metropolitan area was identified because ATL is the 

only commercial service airport in the Atlanta metropolitan area, which leaves no 

opportunity for relief of the congestion occurring there. 

IV
5 airports that need

additional capacity

5 airports that need 

additional capacity

1 metro area that needs

additional capacity

1 metro area that needs

additional capacity

Figure ES - 1. Airports and Metro Areas that Need Additional Capacity in 2003 

Capacity needs in 2013 

Future capacity for 2013 was based on planned improvements contained in the OEP 

version 5.0. Even assuming those improvements, 15 airports are identified as needing 

additional capacity (see Figure ES-2): 

• Metropolitan Oakland International (OAK) 

• Bob Hope (Burbank, CA) (BUR) 

• Long Beach (LGB) 

• John Wayne-Orange County (SNA) 

• Tucson International (TUS) 

• Albuquerque International Sunport (ABQ) 

• San Antonio International (SAT) 

• Houston Hobby (HOU) 

• Chicago O’Hare International (ORD)1

• New York LaGuardia (LGA) 

• New York Kennedy International (JFK) 

 

1

 Note that OEP v.5.0 did not include the O’Hare Modernization Plan (OMP), which will 

reconfigure the runways at ORD for additional capacity. However, the effects of the OMP are

included in the 2020 analysis. 

V
• Newark Liberty International (EWR) 

• Philadelphia International (PHL) 

• Palm Beach International (PBI) 

• Fort Lauderdale-Hollywood International (FLL). 

Seven metropolitan areas are also identified as needing additional capacity by 2013: San 

Francisco Bay, Los Angeles Basin, Tucson, Austin-San Antonio, Chicago, New York

Metro, and South Florida. 

15 airports that will need

additional capacity

15 airports that will need

additional capacity

7 metro areas that will need 

additional capacity

7 metro areas that will need 

additional capacity

Note: Some airports and metropolitan areas were only

identified with additional socio-economic information

Figure ES - 2. Airport and Metro Areas that Need Additional Capacity in 2013 

(After Assumed Improvements) 

Most of these airports and metropolitan areas are located in the southern part of the 

country where shifts in population and the industrial base are occurring. Furthermore, if 

the improvements proposed in the OEP do not take place, the number of airports with 

capacity problems in 2013 jumps from 15 to 26. 

Capacity needs in 2020 

For the year 2020, future capacity was based on assumed improvements in technology 

and procedures, as well as the implementation of runway construction projects not listed 

in the OEP. Even with those assumed improvements, 18 airports are identified as likely 

needing additional capacity (see Figure ES-3): 

• Metropolitan Oakland International (OAK) 

• Bob Hope (Burbank, CA) (BUR) 

VI
• Long Beach (LGB) 

• John Wayne-Orange County (SNA) 

• Ontario International (ONT) 

• Las Vegas McCarran International (LAS) 

• Tucson International (TUS) 

• Albuquerque International Sunport (ABQ) 

• San Antonio International (SAT) 

• Houston Hobby (HOU) 

• Chicago Midway International (MDW) 

• Birmingham International (BHM) 

• Hartsfield-Jackson Atlanta International (ATL) 

• Bradley International (BDL: Windsor Locks, CT) 

• T.F. Green (PVD: Providence, RI) 

• Long Island MacArthur (ISP) 

• New York LaGuardia (LGA) 

• Newark Liberty International (EWR). 

18 airports that will need

additional capacity

18 airports that will need

additional capacity

8 metro areas that will need 

additional capacity

8 metro areas that will need 

additional capacity

Note: Some airports and metropolitan areas were only

identified with additional socio-economic information

Figure ES - 3. Airport and Metro Areas that Need Additional Capacity in 2020 

(After Assumed Improvements) 

VII
Eight metropolitan areas are identified as likely needing additional capacity by 2020: San 

Francisco Bay, Los Angeles Basin, Las Vegas, Tucson, Austin-San Antonio, 

Birmingham, Atlanta, and New York Metro. As is true in 2013, most of these airports 

and metropolitan areas are occurring in the southern part of the country where shifts in 

population and the industrial base are occurring. 

Again, however, if no improvements over today’s level of capacity take place, the 

number of capacity-constrained airports rises from 18 to 41. 

Other Airports with Capacity or Delay Constraints that Warrant Further 

Action

The FAA believes that the criteria used in this study has produced results that accurately 

reflect where our efforts at capacity enhancement should be directed. However, any 

study that attempts to identify the most significant areas where capacity constraints are 

likely to occur may not capture all of the dynamics associated with growth in demand and 

resultant delay. This is a constantly changing, very fluid environment. While the criteria 

developed and applied in this study proved to be a useful filter for determining significant 

capacity needs, it must be recognized that a number of airports not meeting the highly 

selective criteria used in this study, may need to capitalize on local capacity enhancement 

opportunities. Such airports as Dulles International (IAD), San Diego International 

(SAN), and San Francisco International (SFO) certainly fall within this group and further 

examination of these locations among others may be necessary: 

• At IAD, the likelihood that new carriers (e.g., Independence Air and TED) will 

shortly add flights at this airport, adds to concerns about adequate capacity. Much 

more rapid growth may be experienced at this location than is suggested by recent 

forecasts. 

• SAN is the only large-hub airport in the U.S. with a single, range-limited air 

carrier runway. The airport has geographic and terrain issues that constrain its 

ability to adequately handle future growth. The airfield is constrained by 

displaced thresholds and numerous modifications to standards. Furthermore, due 

to these issues and the type of activity at this facility, SAN may not be able to 

realize the capacity benefits of future technology assumed in this study. The FAA 

is aware of the studies completed by the airport sponsor that support the need for 

additional capacity within the 2020 timeframe. As a result of these unique issues, 

further study of SAN is indicated. 

• Because of the increasing traffic levels at SFO and higher levels of forecast 

demand, a separate sensitivity analysis based on the 2003 TAF was conducted. 

This analysis indicates that SFO could be in need of additional capacity as early 

as 2015. 

The stated purpose of this study is to identify airports and metropolitan areas with present 

or future capacity problems. However, a number of airports are dealing with important 

issues associated more with delay reduction than with increase in capacity and are as 

deserving of attention. Such airports as Boston Logan International and Seattle-Tacoma

VIII
International should be included in this category. The new runways at each of these 

airports are will help better manage the peak levels of delay that each currently 

experiences.

A System in Transition

These results are based upon forecasts of an unknown future. Changes in future demand 

and capacity projections are likely as the underlying assumptions are updated. The 

difference between the 2002 TAF and the recently released 2003 TAF is one example of 

this. (See Appendix D for a discussion of the sensitivity analysis performed using the FY 

2003 TAF.) As different forecasts are developed and system enhancement plans mature 

over time, the results of a study such as this will likely change as well. In addition, major 

changes that occur locally, such as the introduction of a new air carrier expected at 

Washington Dulles International (IAD) in the summer of 2004, can drastically alter 

future demand predictions. These alterations can suddenly change the situation at an 

airport from having adequate capacity to needing more capacity for the new levels of 

demand. For these reasons it is important to track changes in assumptions over time and 

then update analytic results accordingly. 

Conclusions

• The predominant trend over the next two decades largely will be the expansion of 

existing airports to meet forecast demand. Because of the long lead times 

necessary to bring large complex runway projects on line, current improvement 

plans must move forward to keep pace with demand forecast for 2013. If the 

planned improvements do not occur for any reason, the number of airports 

experiencing capacity shortages will grow sharply. 

• The long lead times also necessary to move research out of the lab and into the 

field, to equip aircraft with the latest technologies, and to implement procedural 

changes require that this vital work move forward to address future 

demand/capacity mismatches in 2013 and 2020. 

• This study focused on three distinct time periods: 2003, 2013 and 2020. 

Although some airports do not meet the criteria for needing additional capacity in 

the time periods studied, it is possible that they would meet the criteria in 

intermediate years (prior to the implementation of the improvements considered 

in this report). In other words, some airports not meeting these criteria until 2020 

may actually reach that state as early as 2014. This highlights the need to press 

ahead with development plans. 

• Even planned improvements will not be sufficient at some locations. Therefore, 

plans for capacity enhancements, including new runways and, in limited cases, 

new airports must continue and more new runways must be planned. 

• Ambitious assumptions were made for improvements projected for 2020; some of 

these improvements may not materialize and even these assumed improvements 

will not be sufficient at some locations. Most importantly, the majority of the 

assumed improvements in 2020 do not have formal plans associated with them. 

IX
This makes it ever more important to begin to formalize capacity improvement 

plans for the 2020 timeframe. 

• Additional analyses are necessary to develop possible solutions for the identified 

airports; this is particularly true for the non-OEP airports in order to gain a better 

understanding of their capabilities, operations, and local regulations. 

• For all the airports, detailed feedback and information obtained through 

discussions with them will need to be incorporated into future iterations of this 

study. Solutions beyond those considered here, including policy options, need to 

be explored. 

• In addition to new runways and airports, procedures, technologies, and policy 

options should be explored. 

• The FAA must manage its budget and programs responsibly to ensure that the 

development of new technological improvements remains on track. 

X
Capacity Needs in the National Airspace System Report 

An Analysis of Airport and Metropolitan Area Demand and 

Operational Capacity in the Future 

Purpose 

This study was undertaken because the Federal Aviation Administration wanted to assure 

that the long-term capacity of the aviation system matched forecasts of demand. It is 

important to look not only at individual airports in the longer term, but also at the 

infrastructure of the airport network to ensure sufficient capacity to meet that demand. 

To that end, two basic questions were asked by the FAA: 

• Which of the 35 Operational Evolution Plan (OEP) airports will be able to meet 

future demand and which will not and why? 

• Besides the 35 OEP airports, will there be other geographic areas of the country 

unable to accommodate demand for air transportation?

In March 2003, a team was assembled to develop answers to these questions. The team, 

led by the Airports organization (ARP), and including representatives of the Air Traffic 

Organization (ATO) and the MITRE Corporation’s Center for Advanced Aviation 

System Development (CAASD), began the Future Airport Capacity Task (FACT), an 

assessment of the future capacity of the nation’s airports and metropolitan areas. The 

goal of the Future Airport Capacity Task was to determine which airports may need 

additional capacity in the future and why. In addition to identifying the airports, any 

constraints and limitations to enhancing their capacity were also examined. 

The OEP is a 10-year plan to increase the capacity and efficiency of the National 

Airspace System. It focuses on infrastructure - - primarily new runways - - and 

technological and procedural initiatives. The first OEP report was issued in December of 

2001. It is published annually. It focuses on 35 of the busiest US airports (the 31 large 

hubs plus MEM, CLE, DCA, and PDX). It is divided into four core problem areas: 

airport weather condition, en route severe weather, en route congestion, and 

arrival/departure rate. FAA’s Airports organization determines when a proposed runway 

is ready for inclusion in the OEP and monitors its progress with support from the Air 

Traffic, System Capacity, and Region and Center Operations organizations in the FAA. 

A new runway at an OEP airport is added when we are reasonable certain of its 

alignment, schedule, configuration, and planned use. 

There have been several well-documented studies to evaluate airport capacity at the 

busiest 35 airports. Annual Service Volume

2

 (ASV), Airport Capacity Benchmarks, and 

 

2

 FAA Advisory Circular 150/5060-6 Airport Capacity and Delay, Date 9/23/83, Chapter 1. 

Airport Capacity and Aircraft Delay, Section 1-3. Capacity Terms, b. Annual Service Volume 

(ASV) 

1
the OEP System Performance Assessment3

 are three of these studies. The focus of the 

FACT effort was to bring these studies together in order to develop a very selective 

criteria set highlighting airports (or associated metropolitan areas) that have the most 

significant capacity needs. If an airport failed to meet the criteria of any individual study, 

then it was not identified by the FACT study as a member of the common list of airports 

needing additional capacity. Airports not identified in this analysis may have been 

identified in one or more of the studies, but not in all of them. Because the requirement 

for commonality was so strict, the results of this assessment should be viewed as a list of 

airports in the greatest need of additional future capacity among a larger group of airports 

facing significant capacity constraints. 

The initial focus of this effort concentrated on the 35 airports currently tracked as part of 

the FAA’s Operational Evolution Plan (OEP), version 5.0. This analysis was later 

expanded to include 291 commercial service airports in 223 metropolitan areas across the 

country. The idea of expanding the list beyond the top 35 airports was to approach the 

question of which airports and metropolitan areas of the country may be unable to 

accommodate demand for air transportation in 2020. For airports other than the top 35, a 

future demand predicted to be at least 90 percent of available capacity was used to 

indicate a need for additional capacity. As more detailed modeling is done in the future, 

a similar set of criteria to that used for the top 35 airports will be utilized. 

Due to data limitations, a simplified approach was taken for airports beyond the top 35. 

Although more detailed assessments were performed whenever possible, the results for 

these airports should still be regarded as preliminary until more detailed analyses can be 

completed. This study is intended to complement detailed local airport planning 

activities, not as a substitute for such efforts. Where more detailed studies are available 

at individual locations, the results of those studies should be carefully considered in 

planning future capacity improvements and airport development. 

By using multiple methodologies and criteria, this study has identified those airports with 

the most obvious need for additional capacity in the future. But clearly, other airports not 

identified by this study are in need capacity improvements. One should not assume that 

these airports will have adequate capacity. Many airports not identified in this analysis

must continue to plan for future capacity improvements. The purpose of this analysis 

was to look across the NAS to highlight the most obvious capacity shortcomings, in order 

to help guide future analysis and planning; not to be the sole determinant of where 

capacity improvements will be necessary. 

At some airports, projects are currently underway to address problems other than capacity 

such as delay reduction. As the FACT is focused on increasing capacity, these airports 

and their need for such improvements may not have been identified on the common list. 

However, it is important that these projects continue to move forward. 

 

3

 Solomos et al., Modeling NAS Performance Assessment Results of OEP 5.0, 8 December 2003, 

The MITRE Corporation, McLean, VA 

2
Coordination With Affected Airports

In January and February 2004 the FACT analysis was coordinated with each of the 

airports identified as needing additional capacity in the future, some 24 airport sponsors 

in total. We wanted to provide each facility with the assumptions we used regarding fleet 

mix, runway configuration and any constraints or limitations to the operational flexibility 

of the airport. In most cases, the airports agreed with our assumptions, while others 

thought we were overly aggressive particularly with the longer-term enhancements. In 

those cases, we adjusted our assumptions to be more in line with those of the airport. 

Although each coordination meeting with the airports was different, there were several 

common issues that were repeated from airport to airport. While these will not be 

specifically discussed here, a summary of these commonalities follows: 

• Airfield is not necessarily the limiting factor. Terminal Buildings limit the 

number of annual passengers, which in turn limits the number of operations. If 

terminals could be expanded, operations may increase placing an additional 

burden on the airfield. 

• General Aviation. Many of the airports that we visited had a significant general 

aviation (GA) operation. In many cases these are “high end” GA, business jet 

type aircraft that typically use the main air carrier runway rather than a shorter 

GA runway. A fast growing segment of the GA community is the fractional 

ownership of aircraft. Since there may be several owners of such an aircraft the 

number of operations may increase at a much greater rate than based aircraft. 

These fractional ownership aircraft are also high end GA, and may be as large as 

the Boeing 737 Business Jet. 

• Airspace limitations. The ability of the airspace around many of the airports to 

accommodate more arrivals and departures may be limited, especially where 

several major airports are in the same area (Southern California, Northern 

California, New York/Philadelphia, and Southern Florida). Enroute airspace 

congestion may also impose departure delays. In other cases, operational 

flexibility may be affected by nearby military airspace or environmentally 

sensitive areas. 

• Roadway limitations. As airports are gaining additional passengers and traffic, 

particularly the smaller commercial service airports, a limiting factor is the offairport roadway network. The roads leading into the airports are not able to 

accommodate this increase in surface traffic without congestion. At some airports 

the curb frontage and adjacent through lanes are not adequate for passenger dropoff and pick-up. New TSA regulations have also limited the curb frontage at 

many of the smaller airports. 

Findings of the Study

• As air traffic levels continue to grow over time, it is well known that the 

additional demands placed upon the NAS will strain the system’s capacity. 

3
However, the FACT analysis shows that even today there are areas in the NAS 

where additional capacity is needed, and these needs will grow even stronger as 

traffic levels continue to increase. Based upon this study, it is expected that 

approximately 5 percent of the nearly 300 airports analyzed will require 

additional capacity by either 2013 or 2020. 

• This study indicates that airports other than the top 35 tracked by the FAA’s 

current OEP will potentially need additional capacity in the future. As more 

detailed studies are performed at those airports, it may be shown that they warrant 

inclusion in the OEP to better track planned improvements over time. 

• Growth trends will continue to affect many of the same metropolitan areas that 

historically have had a need for additional capacity. This study indicates that the 

predominant trend over the next two decades largely will be the expansion of 

existing airports to meet the forecast. At the same time, new metropolitan areas 

have emerged as needing additional capacity in the future. These metropolitan 

areas are mostly in the south and southwest. Increases in air traffic congestion in 

some metropolitan areas, however, may lead to the establishment of new 

supplemental airports such as the proposed Ivanpah Airport near Las Vegas, NV 

and the proposed South Suburban Airport near Chicago, IL. (A replacement 

airport at San Diego, CA may also be a possibility.) 

The findings of the analysis done for each of these three years are discussed below. 

Appendix B contains a list of the airports considered as part of the metropolitan areas 

described below: 

Capacity Needs in 2003 

Using the demand and capacity measures described later in the section on scope and 

methodology, the FACT analysis has identified five airports where additional capacity is 

already necessary today. (See Figure 1). Airfield configuration, airspace limitations and 

the volume of activity contribute to the capacity needs of the following five airports: 

• Hartsfield-Jackson Atlanta International (ATL) 

• Newark Liberty International (EWR) 

• New York LaGuardia (LGA) 

• Chicago O’Hare International (ORD) 

• Philadelphia International (PHL). 

Improvements to address the capacity needs of these airports, such as a new runway at 

ATL and airspace redesign in New York, are already underway or in the works. The 

rapid growth in operations at some airports has also triggered policy change related to 

acceptable traffic levels, such as that which occurred at ORD this past year. 

4
5 airports that need

additional capacity

5 airports that need 

additional capacity

1 metro area that needs

additional capacity

1 metro area that needs

additional capacity

Figure 1. Airports and Metro Areas that Need Additional Capacity in 2003 

In addition to these airports, the Atlanta metropolitan area has also been identified as 

needing additional capacity. The Atlanta metropolitan area was identified because ATL 

is the only commercial service airport in the Atlanta metropolitan area, which leaves no 

opportunity for relief of the congestion occurring there. Other metropolitan areas, such 

as Chicago and New York, potentially have adequate capacity available to them due to 

the existence of multiple commercial service airports with excess capacity. Individual

airports within these metro areas, such as ORD, EWR and LGA, do need additional 

capacity today. However, it may be difficult to shift traffic demand from one airport to 

another within a metropolitan area. 

Capacity Needs in 2013 

By 2013 the need for additional capacity becomes much larger. Plans identified as part 

of the OEP v5.0 are not enough to keep up with the projected levels of demand at the 

following 15 airports even after assumed improvements have been incorporated. (see 

Figure 2): 

• Metropolitan Oakland International (OAK) 

• Bob Hope (Burbank, CA) (BUR) 

• Long Beach (LGB) 

• John Wayne-Orange County (SNA) 

• Tucson International (TUS) 

• Albuquerque International Sunport (ABQ) 

5
• San Antonio International (SAT) 

• Houston Hobby (HOU) 

• Chicago O’Hare International (ORD) 

• New York LaGuardia (LGA) 

• New York Kennedy International (JFK) 

• Newark Liberty International (EWR) 

• Philadelphia International (PHL) 

• Palm Beach International (PBI) 

• Fort Lauderdale-Hollywood International (FLL). 

Seven metropolitan areas are also identified as needing additional capacity by 2013: San 

Francisco Bay, Los Angeles Basin, Tucson, Austin-San Antonio, Chicago, New York

Metro, and South Florida. 

Two of the 15 airports (BUR and PBI), as well as two of the metropolitan areas (Chicago 

and South Florida), were only identified using the socio-economic demand model. 

Figure 2 shows the locations of airports and metropolitan areas needing additional 

capacity. 

15 airports that will need

additional capacity

15 airports that will need

additional capacity

7 metro areas that will need 

additional capacity

7 metro areas that will need 

additional capacity

Note: Some airports and metropolitan areas were only

identified with additional socio-economic information

Figure 2. Airport and Metro Areas that Need Additional Capacity in 2013 

(After Assumed Improvements) 

6
Airfield configuration, airspace limitations and the volume of activity continue to limit 

the capacity of EWR, LGA, ORD and PHL. These factors also contribute to the need for 

additional capacity at FLL and JFK. Airfield redevelopment plans at ORD and PHL have 

not been finalized, so they were not included in this analysis until 2020. The construction 

of a new runway at ATL prior to 2013 results in the airport dropping off the list, at least 

for that year. 

Airports such as ABQ, BUR, HOU, LGB, OAK, PBI, SAT, SNA, and TUS are also 

expected to experience a need for additional capacity. It is interesting to note that these 

airports are located across the entire southern part of the country from coast to coast. 

Growth in population and income in the surrounding metropolitan areas are a major cause 

of anticipated future demand. 

Significant growth in the Chicago, LA Basin, New York and San Francisco Bay 

metropolitan areas indicate a possible need for additional capacity. In addition, expected 

growth in the Austin-San Antonio, South Florida, and Tucson metropolitan areas indicate 

a need for additional capacity. Tucson is similar to Atlanta in that it has only one 

commercial service airport considered in the metropolitan area. 

The Atlanta metropolitan area is expected to have adequate capacity by the 2013 time 

frame. The construction of the new runway at ATL increases the available capacity at the 

airport, thus affecting the entire metropolitan area.

If for any reason the planned improvements assumed at each of the airports in this 

analysis do not occur by 2013, the number of airports needing additional capacity may 

climb to as high as 26 airports: the 15 previously discussed as well as 11 additional 

airports (see Figure 3). 

As already stated, the assumed improvements are aggressive in some cases and uncertain 

in others. The OEP, used as a basis for our capacity assumptions in 2013, is a ‘rolling’ 

10-year plan and is updated annually. These updates included additional improvements, 

removal of some plans, and a retiming of others (either earlier or later than originally 

planned). Therefore, it is possible that some or all of these additional airports would 

experience a need for additional capacity by 2013. Furthermore, assuming that all 

planned improvements are implemented by 2013, it is still possible that at some time

between 2003 and the incorporation of the planned improvements, the airport(s) may 

experience a capacity shortage. This illustrates the importance of following through on

planned improvements as well as the need for additional plans to be put in place for 

handling the expected capacity needs.

7
15 airports that will need

additional capacity

15 airports that will need

additional capacity

11 airports that will need

additional capacity if aggressive

assumptions don’t transpire

11 airports that will need

additional capacity if aggressive

assumptions don’t transpire

Note: Some airports were only identified with

additional socio-economic information

Figure 3. Airports that Need Additional Capacity in 2013 

(If Planned Improvements Do Not Occur) 

Capacity Needs in 2020 

For the year 2020, future capacity was based on assumed improvements in technology 

and procedures, as well as the implementation of runway construction projects not listed 

in the OEP. Even with those assumed improvements, 18 airports are identified as likely 

needing additional capacity (see Figure 4): 

• Metropolitan Oakland International (OAK) 

• Bob Hope (Burbank, CA) (BUR) 

• Long Beach (LGB) 

• John Wayne-Orange County (SNA) 

• Ontario International (ONT) 

• Las Vegas McCarran International (LAS) 

• Tucson International (TUS) 

• Albuquerque International Sunport (ABQ) 

• San Antonio International (SAT) 

• Houston Hobby (HOU) 

• Chicago Midway International (MDW) 

• Birmingham International (BHM) 

8
• Hartsfield-Jackson Atlanta International (ATL) 

• Bradley International (BDL: Windsor Locks, CT) 

• T.F. Green (PVD: Providence, RI) 

• Long Island MacArthur (ISP) 

• New York LaGuardia (LGA) 

• Newark Liberty International (EWR). 

18 airports that will need

additional capacity

18 airports that will need

additional capacity

8 metro areas that will need 

additional capacity

8 metro areas that will need 

additional capacity

Note: Some airports and metropolitan areas were only

identified with additional socio-economic information

Figure 4. Airport and Metro Areas that Need Additional Capacity in 2020 

(After Assumed Improvements) 

Eight metropolitan areas are identified as likely needing additional capacity by 2020: San 

Francisco Bay, Los Angeles Basin, Las Vegas, Tucson, Austin-San Antonio, 

Birmingham, Atlanta, and New York Metro. As is true in 2013, most of these airports 

and metropolitan areas are occurring in the southern part of the country where shifts in 

population and the industrial base are occurring. 

Five of the 18 airports (BDL, BHM, BUR, ONT and PVD), as well as one of the eight 

metropolitan areas (Birmingham) identified as needing additional capacity, were only

identified using the socio-economic demand model. Figure 4 illustrates where all of the 

airport and metropolitan areas are located. 

Airfield configuration, airspace limitations and the volume of activity continue to limit 

the capacity of EWR and LGA. These factors also contribute to the need for more 

capacity at MDW and LAS. The growth in traffic at ATL between 2013 and 2020 is 

expected to result once again in the airport having an increased capacity need. 

9
The airports identified in the 2013 analysis (ABQ, BUR, HOU, LGB, OAK, SAT, SNA, 

and TUS) continue to need additional capacity. Additional airports (BHM, BDL, ISP, 

ONT, and PVD) also appear as capacity constrained by 2020. While the southern part of 

the country will continue to need more capacity, traffic growth is affecting the northeast 

corridor as well by this time period.

Several airports identified as needing additional capacity in 2013 no longer appear 

capacity constrained by 2020. If the construction of a new runway extension at FLL 

takes place, then the airport will be able to accommodate demand and the additional 

capacity need identified in the 2013 time period will be satisfied. Technology and 

airspace improvements should provide relief at JFK. Aggressive assumptions for the 

airfield reconfigurations at ORD and PHL were used in the 2020 analysis. Using these 

assumptions the airports are expected to have sufficient capacity to meet demand growth. 

PBI is expected to open a new runway by 2020 alleviating its need for additional 

capacity. 

Five of the metropolitan areas identified in 2020 were also noted in the 2013 analysis. 

Continued growth in the Austin-San Antonio, LA Basin, New York, San Francisco Bay 

and Tucson metropolitan areas continue to drive a need for additional capacity. Although 

by 2013 Atlanta metropolitan area is expected to have sufficient capacity to meet demand 

projections, the continued growth in the region places Atlanta into a situation potentially 

requiring additional capacity by 2020. The Birmingham and Las Vegas metropolitan

areas (which contain only one commercial service airport each in this study) were also

identified as needing additional capacity. The reconfiguration of ORD and the 

construction of a new runway at PBI will add sufficient capacity to satisfy expected 

demand levels in the Chicago and South Florida metropolitan areas. 

As was shown in the 2013 analysis, if for any reason the planned improvements assumed 

at each of the airports in this analysis do not occur by 2020, the number of airports 

needing additional capacity may climb to as high as 41 airports: the 18 previously 

discussed as well as 23 additional airports (see Figure 5). Once again it is possible that

some or all of these additional airports would experience a need for additional capacity 

by 2020. Furthermore, as was true in the 2013 analysis the exact timing of these 

improvements is not illustrated. It is possible that at some time between 2013 and the 

incorporation of the improvements the airport(s) may experience a capacity shortage. 

This illustrates the importance of following through on planned improvements as well as 

the need for additional plans to be put in place for handling the expected capacity needs. 

Again, however, if no improvements over today’s level of capacity take place, the 

number of capacity-constrained airports rises from 18 to 41. 

10
18 airports that will need

additional capacity

18 airports that will need

additional capacity

23 airports that will need

additional capacity if aggressive

assumptions don’t transpire

23 airports that will need

additional capacity if aggressive

assumptions don’t transpire

Note: Some airports were only identified with

additional socio-economic information

Figure 5. Airports that Need Additional Capacity in 2020 

(If Planned Improvements Do Not Occur) 

Other Airports with Capacity or Delay Constraints that Warrant Further 

Action

The FAA believes that the criteria used in this study has produced results that accurately 

reflect where our efforts at capacity enhancement should be directed. However, any 

study that attempts to identify the most significant areas where capacity constraints 

arelikely to occur may not capture all of the dynamics associated with growth in demand 

and resultant delay. This is a constantly changing, very fluid environment. While the 

criteria developed and applied in this study proved to be a useful filter for determining 

significant capacity needs, it must be recognized that a number of airports not meeting 

the highly selective criteria used in this study, may need to capitalize on local capacity 

enhancement opportunities. Such airports as Dulles International (IAD), San Diego 

International (SAN), and San Francisco International (SFO) certainly fall within this 

group and further examination of these locations among others may be necessary: 

• At IAD, the likelihood that new carriers (e.g., Independence Air and TED) will 

shortly add flights at this airport, adds to concerns about adequate capacity. Much 

more rapid growth may be experienced at this location than is suggested by recent 

forecasts. 

• SAN is the only large-hub airport in the U.S. with a single, range-limited air 

carrier runway. The airport has geographic and terrain issues that constrain its 

ability to adequately handle future growth. The airfield is constrained by 

displaced thresholds and numerous modifications to standards. Furthermore, due 

11
to these issues and the type of activity at this facility, SAN may not be able to 

realize the capacity benefits of future technology assumed in this study. The FAA 

is aware of the studies completed by the airport sponsor that support the need for 

additional capacity within the 2020 timeframe. As a result of these unique issues, 

further study of SAN is indicated. 

• Because of the increasing traffic levels at SFO and higher levels of forecast 

demand, a separate sensitivity analysis based on the 2003 TAF was conducted. 

This analysis indicates that SFO could be in need of additional capacity as early 

as 2015. 

The stated purpose of this study is to identify airports and metropolitan areas with present 

or future capacity problems. However, a number of airports are dealing with important 

issues associated more with delay reduction than with increase in capacity and are as 

deserving of attention. Such airports as Boston Logan International and Seattle-Tacoma

International should be included in this category. The new runways at each of these 

airports are will help better manage the peak levels of delay that each currently 

experiences.

A System in Transition

These results are based upon forecasts of an unknown future. Changes in future demand 

and capacity projections are likely as the underlying assumptions are updated. The 

difference between the 2002 TAF and the recently released 2003 TAF is one example of 

this. (See Appendix D for a discussion of the sensitivity analysis performed using the FY 

2003 TAF.) As different forecasts are developed and system enhancement plans mature 

over time, the results of a study such as this will likely change as well. In addition, major 

changes that occur locally, such as the introduction of a new air carrier expected at 

Washington Dulles International (IAD) in the summer of 2004, can drastically alter 

future demand predictions. These alterations can suddenly change the situation at an 

airport from having adequate capacity to needing more capacity for the new levels of 

demand. For these reasons it is important to track changes in assumptions over time and 

then update analytic results accordingly. 

Scope and Methodology

There have been several well-documented studies to evaluate airfield capacity at the 

busiest 35 airports. The purpose of the FACT effort was to bring these studies together in 

order to develop a very selective criteria set highlighting airports (or associated 

metropolitan areas) that have the most significant capacity needs. If an airport failed to 

meet the criteria of any individual study, then it was not identified by the FACT study as 

a member of the common list of airports needing additional capacity. Airports not 

identified in this analysis may have been identified in one or more of the studies, but not 

in all of them. Because the requirement for commonality was so strict, the results of this 

assessment should be viewed as a list of airports in the greatest need of additional future 

capacity among a larger group of airports facing significant capacity constraints. 

12
Bringing these studies together required extensive amounts of information to ensure 

consistency among them, including information on: 

• current operations 

• current capacity at individual airports 

• how operations may change in the future 

• how new technologies and runways will contribute to increasing airport capacity 

• what demand levels are likely to exist in the future

• where that demand is most likely to occur. 

Once this information was gathered it was possible to perform the necessary analyses to 

identify where additional capacity may be necessary. An understanding of current day 

operations as well as the amount of capacity provided at individual airports today was 

necessary. How operations may change in the future as well as how new technologies 

and runways will contribute to increasing airport capacity needed to be determined. 

Demand levels that would likely exist in the future and where that demand was most 

likely to occur needed to be taken into account. Appendix C contains a more detailed 

discussion of the scope and methodology. 

Top 35 airports 

The initial focus of this effort concentrated on the 35 airports currently tracked as part of 

the OEP. To be identified on the common list of airports it was necessary for these 

airports to satisfy the criteria of each individual study, under two different future traffic 

level assumptions: one using the 2002 Terminal Area Forecast (TAF) and the other using 

demand estimates produced by CAASD’s experimental model of origin and destination 

(O&D) traffic (a total of six criteria). If any of the criteria was not met in either future

demand scenario, then an airport was not included on the common list. Because the 

requirement for commonality was so strict, the results of this assessment should be 

viewed as a minimal list of airports needing additional future capacity. The specific 

criteria used for each individual study are described below: 

• Annual Service Volume (ASV): The annual level of traffic that results in a 

given level of average delay, known as ASV, was calculated as part of the 

capacity assessment used in this analysis. ASV considers multiple runway 

configurations and utilizes an annual estimation of weather conditions for each 

configuration in its calculation. A ratio of annual demand to ASV estimated at 

0.8 or above (demand at least 80% of capacity) was an indication that an airport 

may need additional capacity. 

• NAS-wide simulation of airport arrival delay: Another way of estimating the 

future performance of airports is by using a simulation model to estimate future 

levels of delay. Capacity information is combined with traffic information and 

used as inputs to a simulation model. The model then calculates average delay for 

individual airports. High levels of delay indicate a potential need for additional 

capacity while lower levels of delay could indicate adequate capacity to meet 

13
demand expectations. For the purpose of this analysis, average arrival delay 

estimated at 12 minutes per flight or above was an indication that an airport may 

need additional capacity.

• Extrapolation of historical data: A third way to estimate future performance is 

to use historical data to extrapolate potential changes in performance while 

accounting for changing levels of demand and capacity. Using the FAA’s 

Aviation System Performance Metrics (ASPM) database, “Airborne Delay” was 

used as an estimate of the arrival delay due to capacity at the airport, and “Taxi 

Out Delay” was used as a measure of airport-related departure delay. Also 

calculated was the ratio of annual traffic to an annualized capacity at each airport 

(based upon hourly airport capacities in VMC, MMC, and IMC). If the 

extrapolated delay was estimated to exceed 4.5 minutes per flight or the 

demand/capacity ratio was 0.95 or above, that was an indication that an airport 

may need additional capacity. 

Recall that each of these criteria needed to be satisfied under each traffic level 

assumption. Requiring the criteria to be met using the two different traffic levels 

provided some level of sensitivity analyses around the results. 

Other airports 

This analysis was later expanded to include nearly 300 commercial service airports across 

the country, including an analysis of metropolitan area capacity. The reason for 

expanding the list beyond the top 35 airports was to approach the question of which 

airports and metropolitan areas may need additional capacity in the future. The 

information available about, and the knowledge of, the top 35 airports was much more 

extensive than the information about these other airports. Because of this, the criteria 

used in this assessment for the top 35 airports were much more stringent than the criteria 

for the other airports. For airports beyond the top 35, a simple analysis of annual demand 

versus annualized capacity was performed. If the predicted demand was expected to be 

at least 90% of the available capacity, that was an indication that an airport may need 

additional capacity. As more detailed modeling is done in the future, a set of criteria 

similar to that used for the top 35 airports will be utilized. 

Socio-economic demand modeling 

The principal forecast of future operations was the 2002 TAF. For the OEP 35 airports, 

the TAF makes projections of future enplanements and operations on an airport-byairport basis based upon the economic and demographic characteristics of the airport 

metropolitan area. As a secondary source of information, this analysis also considered 

demand estimates produced by CAASD’s experimental model of origin and destination 

(O&D) traffic. Similar to the TAF, this model produces forecasts of demand based upon 

the economic and demographic trends. Unlike the TAF though, the model produces 

forecasts of traffic for individual pairs of origin and destination metropolitan areas. 

Socio-economic trend information, including changes in demographics, income, market 

power, and other factors, were considered as part of this analysis. Passenger demand was 

estimated as originating in, or traveling to, a metropolitan area rather than a specific 

14
airport. This passenger demand was then translated into airport operations through a 

route selection process (direct or via a third airport) and by determining the correct 

aircraft fleet necessary to handle the passenger traffic. This additional estimate of future 

traffic levels was then utilized as part of the demand/capacity analysis. 

Capacity modeling 

Three years were selected for analysis: 2003 was used as the present-day baseline; 2013 

was chosen because it is the last year covered by version 5 of the OEP; and 2020, because 

it was the time horizon of the 2002 TAF. The 2013 evaluation assumed that all new 

runways and procedural improvements outlined in the FAA’s Operational Evolution Plan

(OEP), version 5.0 would be implemented at the top 35 airports. For the 2020 capacity 

assessment, all active plans for additional runways and airport reconfigurations were 

taken into account. Also included were optimistic assumptions about future technology 

and procedures at the top 35 airports. These assumptions were based on various research 

proposals and extrapolations from the latest OEP because there is no similar report that 

would indicate likely capacity improvements by 2020. 

Conclusions

• Because of the long lead times necessary to bring large complex runway projects 

on line, current improvement plans must move forward to keep pace with demand 

forecast for 2013. Such projects are not subject to small perturbations in demand 

of only a few years duration. If the planned improvements do not occur for any 

reason, the number of airports experiencing capacity shortages will grow sharply. 

• The long lead times also necessary to move research out of the lab and into the 

field, to equip aircraft with the latest technologies, and to implement procedural 

changes require that this vital work move forward to keep pace with demand 

forecasts for 2013 and 2020. 

• This study focused on three distinct time periods: 2003, 2013 and 2020. 

Although some airports do not meet the criteria for needing additional capacity in 

the time periods studied, it is possible that they would meet the criteria in 

intermediate years (prior to the implementation of the improvements considered 

in this report). In other words, some airports not meeting these criteria until 2020 

may actually reach that state as early as 2014. This highlights the need to press 

ahead with development plans. 

• Even planned improvements will not be sufficient at some locations. Therefore, 

plans for new airports and new runways must continue and more new runways 

must be planned. 

• Ambitious assumptions were made for improvements projected for 2020; some of 

these improvements may not materialize and even these assumed improvements 

will not be sufficient at some locations. Most importantly, the majority of the 

assumed improvements in 2020 do not have formal plans associated with them. 

This makes it ever more important to begin to formalize capacity improvement 

plans for the 2020 timeframe. 

15
• Additional analyses are necessary to develop possible solutions for the identified 

airports; this is particularly true for the non-OEP airports in order to gain a better 

understanding of their capabilities, operations, and local regulations. 

• For all the airports, detailed feedback and information obtained through 

discussions with them will need to be incorporated into future iterations of this 

study. Solutions beyond those considered here, including policy options, need to 

be explored. 

• The sensitivity analysis performed using the newly released 2003 Terminal Area 

Forecast did not cause the FAA to alter the findings of this study. The analysis 

did determine that there may be a small number of locations that may be added to 

or deleted from this list in a future detailed analysis. See Appendix D for a 

discussion of the sensitivity analysis. 

• In addition to new runways and airports, procedures, technologies, and policy 

options should be explored. 

• The FAA must manage its budget and programs responsibly to ensure that the 

development of new technological improvements remains on track. 

16
Appendix A: Location Identifiers 

The following is a listing of the airports referenced in this paper. 

ABQ ALBUQUERQUE INTERNATIONAL SUNPORT

ATL HARTSFIELD - JACKSON ATLANTA INTERNATIONAL

BDL BRADLEY INTERNATIONAL

BHM BIRMINGHAM INTERNATIONAL 

BOS BOSTON LOGAN INTERNATIONAL

BUR BOB HOPE (BURBANK, CA) 

BWI BALTIMORE-WASHINGTON INTERNATIONAL 

CLE CLEVELAND HOPKINS INTERNATIONAL

CLT CHARLOTTE DOUGLAS INTERNATIONAL

CVG CINCINNATI/NORTHERN KENTUCKY INTERNATIONAL

DCA RONALD REAGAN WASHINGTON NATIONAL

DEN DENVER INTERNATIONAL 

DFW DALLAS-FORT WORTH INTERNATIONAL 

DTW DETROIT METROPOLITAN WAYNE COUNTY

EWR NEWARK LIBERTY INTERNATIONAL

FLL FORT LAUDERDALE-HOLLYWOOD INTERNATIONAL

HNL HONOLULU INTERNATIONAL

HOU HOUSTON WILLIAM P HOBBY

IAD WASHINGTON DULLES INTERNATIONAL 

IAH GEORGE BUSH INTERCONTINENTAL/HOUSTON

ISP LONG ISLAND MACARTHUR

JFK JOHN F KENNEDY INTERNATIONAL

LAS LAS VEGAS MCCARRAN INTERNATIONAL

LAX LOS ANGELES INTERNATIONAL 

LGA LAGUARDIA

LGB LONG BEACH

MCO ORLANDO INTERNATIONAL 

MDW CHICAGO MIDWAY INTERNATIONAL

MEM MEMPHIS INTERNATIONAL

MIA MIAMI INTERNATIONAL

MSP MINNEAPOLIS-ST PAUL INTERNATIONAL 

OAK METROPOLITAN OAKLAND INTERNATIONAL 

ONT ONTARIO INTERNATIONAL

17
ORD CHICAGO O’HARE INTERNATIONAL 

OXR OXNARD

PBI PALM BEACH INTERNATIONAL

PDX PORTLAND INTERNATIONAL

PHL PHILADELPHIA INTERNATIONAL

PHX PHOENIX SKY HARBOR INTERNATIONAL

PIT PITTSBURGH INTERNATIONAL

PVD THEODORE FRANCIS GREEN STATE

SAN SAN DIEGO INTERNATIONAL

SAT SAN ANTONIO INTERNATIONAL

SEA SEATTLE-TACOMA INTERNATIONAL 

SFO SAN FRANCISCO INTERNATIONAL

SLC SALT LAKE CITY INTERNATIONAL 

SNA JOHN WAYNE-ORANGE COUNTY

STL LAMBERT-ST LOUIS INTERNATIONAL 

TPA TAMPA INTERNATIONAL

TUS TUCSON INTERNATIONAL

18
Appendix B: Metropolitan Areas and Associated Airports

The following is a list of the metropolitan areas and the airports that were studied in this 

analysis. 

ABQ ALBUQUERQUE INTERNATIONAL SUNPORT Albuquerque SAF SANTA FE MUNICIPAL

Atlanta ATL HARTSFIELD- JACKSON ATLANTA INTERNATIONAL

AUS AUSTIN BERGSTROM INTERNATIONAL Austin-San Antonio 

SAT SAN ANTONIO INTERNATIONAL

Birmingham BHM BIRMINGHAM INTERNATIONAL 

BDL BRADLEY INTERNATIONAL

BOS BOSTON LOGAN INTERNATIONAL

MHT MANCHESTER

ORH WORCESTER REGIONAL

Boston 

PVD THEODORE FRANCIS GREEN STATE

GYY GARY/CHICAGO INTERNATIONAL

MDW CHICAGO MIDWAY INTERNATIONAL

MKE GENERAL MITCHELL INTERNATIONAL

ORD CHICAGO O’HARE INTERNATIONAL 

Chicago 

RFD NORTHWEST CHICAGOLAND REGIONAL AT ROCKFORD

HOU HOUSTON WILLIAM P HOBBY Houston 

IAH GEORGE BUSH INTERCONTINENTAL/HOUSTON

BUR BURBANK GLENDALE PASADENA

LAX LOS ANGELES INTERNATIONAL

LGB LONG BEACH

ONT ONTARIO INTERNATIONAL

OXR OXNARD

LA Basin 

SNA JOHN WAYNE-ORANGE COUNTY

Las Vegas LAS LAS VEGAS MCCARRAN INTERNATIONAL

EWR NEWARK LIBERTY INTERNATIONAL

HPN WESTCHESTER COUNTY

ISP LONG ISLAND MACARTHUR

JFK JOHN F KENNEDY INTERNATIONAL

LGA LAGUARDIA

New York Metro 

SWF STEWART INTERNATIONAL

19
ABE LEHIGH VALLEY INTERNATIONAL

Philadelphia ACY ATLANTIC CITY INTERNATIONAL

PHL PHILADELPHIA INTERNATIONAL

OAK METROPOLITAN OAKLAND INTERNATIONAL

San Francisco Bay SFO SAN FRANCISCO INTERNATIONAL

SJC MINETA SAN JOSE INTERNATIONAL

FLL FORT LAUDERDALE-HOLLYWOOD INTERNATIONAL

South Florida MIA MIAMI INTERNATIONAL

PBI PALM BEACH INTERNATIONAL

Tucson TUS TUCSON INTERNATIONAL

BWI BALTIMORE-WASHINGTON INTERNATIONAL 

Washington/Baltimore DCA RONALD REAGAN WASHINGTON NATIONAL

IAD WASHINGTON DULLES INTERNATIONAL

Note: The metropolitan areas used for this study were defined by the FACT team for the 

task of jointly evaluating airports that potentially serve the same urban areas. The 

names and definitions of these metropolitan areas do not necessarily correspond 

to those of the federally defined Metropolitan Statistical Areas (MSAs) 

20
Appendix C: Scope and Methodology 

The completion of this study required extensive amounts of information. An 

understanding of current day operations as well as the amount of capacity provided at 

individual airports today was necessary. How operations may change in the future as 

well as how new technologies and runways will contribute to increasing airport capacity 

needed to be determined. Demand levels that would likely exist in the future and where 

that demand was most likely to occur needed to be accounted for. This section will focus 

on the scope of information utilized by this analysis as well as the methodology 

incorporated. In addition to documenting the approach used in both demand and capacity 

modeling, this section will describe the processes applied in the identification of airport 

and metropolitan areas as needing additional capacity. 

Modeling Current and Future Airport Capacity 

Assessing an airport’s capacity requires a comprehensive understanding of its presentday operations and limitations, as well as some assumptions about how the major 

characteristics impacting capacity are expected to change over time. One methodology 

for doing this is found in the Airport Capacity Benchmark Report. The capacities 

documented in that report, which have been updated as a part of the FACT work, provide 

a set of hourly arrival and departure rates under various weather conditions. This 

information can then be used as an input into other models, which in turn produce welldefined measures of airport performance under given assumptions. These measures of 

future airport performance will be discussed later in this section. 

Modeling Current Capacity

The original Airport Capacity Benchmark Report was released by the FAA in April 2001. 

As part of the FACT analysis, the benchmarks reported in the 2001 document have been 

updated and enhanced in the following ways: 

• The original report estimated capacity at 31 of the busiest airports. The update 

increased this number to 35. 

• The original report estimated capacity at each airport under two weather 

conditions: Optimal and Reduced. With this update, capacity estimates were 

completed for three weather conditions, with standardized definitions: 

o Visual Meteorological Conditions (VMC) – Above visual approach 

minima

o Marginal Meteorological Conditions (MMC) – Below visual approach 

minima but ceiling of 1000 ft or more and visibility of 3 miles or more 

o Instrument Meteorological Conditions (IMC). – Below 1000 ft ceiling or 

3 miles visibility 

21
• The original report was based upon how operations were performed in 2000. The 

current benchmarks were updated to include recent capacity improvements and 

changes to operations in 2003. 

• The original report estimated future capacity at each airport based upon the 

FAA’s capacity plans known at that time. The updated capacity estimates are 

based upon the FAA’s Operational Evolution Plan (OEP) version 5.0. 

To produce the capacity estimates necessary for the FACT analysis the team utilized the 

Enhanced Airfield Capacity Model (E-ACM). The E-ACM is a MITRE-developed 

update of the widely used FAA Airfield Capacity Model4

. The E-ACM analytically 

calculates the average number of arrivals and departures that can be expected during busy 

periods at an airport, based on the probabilistic characteristics of aircraft performance. 

The capacity of an airport is strongly influenced by the fleet mix using it. For the 

purpose of running the E-ACM, the fleet mix experienced today was assumed to continue 

in the future. That is, no fleet mix changes were estimated as part of the capacity

analysis. However, both of the operational demand analyses used as inputs by this report 

allowed fleet mix changes to occur in their estimates of future traffic levels. 

Benchmark capacities were calculated for only the airport configurations most commonly 

used under each weather condition. This information was obtained using reported 

configuration data as well as through the use of survey responses by each individual 

facility. Other configurations with less capacity might significantly affect annual 

performance, but this would not be reflected in the benchmark results. 

Finally, model output was compared with historical data and with feedback from the 

individual facilities. 

Modeling Future Capacity 

With 2003 as the present-day baseline, the FACT analysis formulated a set of 

assumptions about what capacity enhancing changes could be reasonably expected in the 

future. The assumed improvements include changes such as new runways, technologies 

or ATC procedures. In its examination of future capacity requirements, the FACT 

analysis focused on the years 2013 and 2020. 

The 2013 evaluation assumed that all new runways and procedural improvements 

outlined in the FAA’s Operational Evolution Plan (OEP), version 5.0 would be 

implemented at the top 35 airports, and would provide the expected benefits. New 

runways were included at 12 of these airports. It is important to note that not every 

proposed runway project was included in the OEP. For example, OEP v5.0 did not 

include new runways at ORD or a runway extension at FLL, since these have not yet 

received final FAA approval. Technical improvements included in OEP v5.0, such as 

 

4

 For more information on the FAA model, see Swedish, W. J., February 1981, Upgraded FAA

Airfield Capacity Model – Volume I: Supplemental User’s Guide, MTR-81W016, Vol. I, The 

MITRE Corporation, McLean, VA 

22
Simultaneous Offset Instrument Approaches (SOIA) at SFO, and visual separation 

between arrivals in marginal weather conditions using cockpit display aids, were also 

assumed to increase capacity at several airports. For airports other than the top 35, only 

planned new runways were considered, but not technological or procedural 

enhancements. 

For the 2020 capacity assessment, all active plans for additional runways and airport 

reconfigurations were taken into account. Analysis of the top 35 airports also included 

optimistic assumptions about future technology and procedures. There is no report 

similar to the OEP that would indicate likely capacity improvements by 2020. Instead, 

the FACT analysis made assumptions based on various research proposals and 

extrapolations from the latest OEP. For example, if a technology was assumed to provide 

visual separations in MMC by 2013, it was assumed that the same technology would be 

able to provide reduced separations under IMC by 2020. Capacity improvements 

assumed for 2020 included some that were applied to all airports, such as reduced radar 

separation minima and controller aids to improve separation accuracy. Other new 

procedures were specific to a given runway configuration, such as SOIA-type approaches 

to closely spaced parallel runways in instrument conditions. For airports other than the 

top 35, only planned new runways were considered, but not technological or procedural 

enhancements. 

Some of these assumptions could be regarded as overly aggressive given the timeframe 

of interest. However, these assumptions were intended to be optimistic. If an airport is 

forecast to be capacity constrained in 2020 despite our optimistic capacity estimates, it is 

an indicator that additional measures will be needed to accommodate the expected traffic, 

such as new runways or changes in demand policy. 

Also, while the assumed improvements would hopefully be implemented in time to 

accommodate the forecast 2020 demand, their availability and effectiveness is by no 

means guaranteed. It would be prudent for airports to consider other means to handle 

future traffic growth, and not to rely on these developmental concepts. 

Incorporating Operational Constraints 

Constraints on how operations are currently performed at each airport were taken into 

consideration in the assessment of current and future capacity. Constraints placed upon

operations for noise, airspace, and arrival and departure procedures were all evaluated. 

Noise mitigation constraints were assumed to continue in the future years. It was 

assumed that some airspace limitations (such as those not caused by terrain) could be 

alleviated with improvements in the future, as could some arrival and departure 

restrictions.

23
Modeling Future Airport Demand 

Simply forecasting airport capacity is not sufficient to identify a future capacity shortfall. 

Forecasts must also be made of future airport demand. Estimated future operations can 

then be compared with estimated future capacity to assess the ability of an airport to 

handle the demands placed upon it. For the FACT study, two different estimates of 

future operations were used. 

The principal forecast of future operations was the FAA’s Terminal Area Forecast, or 

TAF. The TAF makes projections of future enplanements and operations on an airportby-airport basis. Several key inputs into the TAF are forecasts of local economic and 

demographic growth, local fares, and assumptions about dominant carrier behavior. 

The TAF numbers were used by the FACT study in two ways. First, the annual future 

demand estimates were compared directly with future estimates of annualized airport 

capacity to produce a ratio of demand-to-capacity. Second, an algorithm was run to 

develop a forecast traffic scenario based on the TAF. This scenario, which is basically a 

“schedule” for all flights in the NAS, could then be used as an input into a NAS-wide 

simulation model. This model will be discussed later in this section. 

As a secondary source of information, this analysis also considered demand estimates 

produced by CAASD’s experimental bottom-up model of origin and destination (O&D) 

traffic

5

. This socio-economic model, known as the Future Aviation Timetable Estimator, 

or FATE, is based upon the economic and demographic characteristics of individual pairs 

of origin-destination metropolitan areas. This is a different approach than that taken by 

the TAF, as it estimates the amount of passenger traffic between metropolitan areas, 

rather than estimating demand at individual airports. Population, income, and market 

structure all influence passenger demand, as does a host of other factors. Figure C-1 

illustrates where the largest growth is in the United States regarding income and 

population. Also shown are the locations where low fare carriers had at least 15 percent 

of the market share at the start of this analysis (which is rapidly changing). Inputs to the 

model include socio-economic forecasts from the consultancy Global Insight,6

 as well as 

historical data on origin-destination traffic from the Department of Transportation.7

 

5

 Bhadra, D., Demand for Air Travel in the United States: Bottom-Up Econometric Estimation 

and Implications for Forecasts by O&D Pairs, Journal of Air Transportation, Volume 8, 

number 2, pp 19-56, September, 2003 

6

 Global Insight is a consulting firm providing economic and financial data and forecasts. For 

more information see: www.globalinsight.com

7

 For more information see: www.transtats.gov 

24
1. Metro areas with projected population growth of at least 1% p er year and 150,000 from 2000 to 2020.

2. Metro areas with projected real income growth of at least 1% per year and $50 billion from 2000 to 2020.

3. Aircraft indicate large and medium hub airports where low fare carriers have at least 15% market share.

High Population Growth 

1

High Income Growth 

2

Combined Growth

OEP Airport

Low Cost Carrier Market

3

Extensive socio

-

economic

information was included to

identify locations needing

additional capacity that

would not otherwise have

been identified

Figure C-1. Socio-Economic Information 

As shown in Figure C-2, the FATE socio-economic model begins by forecasting O&D 

passengers between metropolitan areas. Then, for each origin-destination pair, 

passengers are allocated among available routes, taking into account the existing air 

carrier network structure. Note that if there are multiple airports within a metropolitan

area, passengers are assigned to one of them as part of this “route choice” process. This 

process is then repeated for all O&D pairs in the contiguous continental U.S. 

Traffic counts can then be

aggregated by airport.

Using forecasts of economic and

demographic drivers, generate

estimates of future O&D travel

demand by metro area pair.

Allocating passengers

among available routes

provides estimates of

connecting traffic. 

Figure C-2. Forecasting Origin and Destination Passengers 

25
At this point there is an estimate of future passenger demand between individual airport 

pairs, including those passengers connecting through hubs. In order to translate this into 

operations, aircraft must be assigned to each airport pair. The size of the aircraft assigned 

depends upon the distance to be flown and the total number of passengers. Adjustments 

are also made to include charter, general aviation, and cargo traffic. The output of the 

model is a set of forecasts of daily and annual passengers and operations between every 

airport pair in the contiguous continental U.S. 

In this study the FATE socio-economic forecasts were used in essentially the same way 

as the Terminal Area Forecast. The socio-economic model generated annual counts of

airport operations in 2013 and 2020, which were then compared to capacity in those years 

at the individual airports and metropolitan areas. The socio-economic forecasts were 

helpful in validating the results obtained with the TAF. 

Process of Identifying Airports Needing Additional Capacity 

Once the forecasting of future demand, as well as the forecasting of future capacity was 

complete it was possible to perform the necessary analyses to identify where additional 

capacity may be necessary. The following will describe the methods used to combine the 

two and arrive at a set of well-defined measures of future operational performance. 

Estimating Future Performance

The following will describe the approaches used to estimate future performance at the 

individual airports: 

Annual Service Volume: The annual level of traffic that results in a given level of 

average delay, known as Annual Service Volume (ASV), was calculated as part of the 

capacity assessment used in this analysis. The level of delay chosen by this analysis as 

appropriate for a given airport was dependent upon that airport’s historical levels of 

delay. A quick analysis of historical delay at the top 35 airports showed the average 

delay per flight on the best delay days was around seven minutes. For airports currently 

experiencing seven minutes of delay per flight or less under the best conditions, the target 

delay level for calculating ASV was set at seven minutes. But for airports currently 

experiencing average levels of delay above seven minutes, even under the best 

conditions, then this higher level was utilized for ASV purposes. This is an important 

point, because the higher the “allowable” delay limit is set at an airport, the higher the 

level of traffic it can handle, as measured by the ASV. 

Note that ASV considers multiple runway configurations and utilizes an annual 

estimation of weather conditions for each configuration in its calculation. Future levels 

of ASV (2013 and 2020) incorporate planned runway improvements/additions, but not 

technological or procedural improvements. 

NAS-Wide Simulation of Airport Arrival Delay: A more rigorous way of estimating 

the future performance of airports is by using a simulation model to estimate future levels 

of delay. Here, capacity information is taken from the updated airport capacity 

26
benchmarks and used as an input to the simulation model. The model is run, and average 

delay is then calculated for individual airports. High levels of expected delay indicate a 

potential need for additional capacity while lower levels of delay could indicate adequate 

capacity to meet demand expectations. In some ways, this is the opposite of the ASV, 

where delay level was fixed and the traffic level was variable. 

The simulation model used by the FACT analysis is a network queuing model of the 

NAS. This model takes demand, capacity, adaptation data, and other information as 

input and produces an estimate of various measures of performance. Because this is a 

network model and flights move from airport to airport throughout the day, the 

performance of one airport impacts the perceived performance of the other airports. For 

example, reducing departure delay at airport A with the addition of a capacity 

improvement also improves the arrival delay at airport B as arrivals at B are no longer 

being delayed upon departure from A. It is this interaction between airports and other 

system resources that makes the system-wide modeling a powerful tool in capacity 

analyses. 

In order to properly account for the interaction between demand and capacity, the NASwide model used by the FACT task simulates all traffic through the NAS, not just traffic 

between certain airports of interest. Demand information is derived from various sources 

including the Official Airline Guide8

 and estimates of general aviation, cargo, and 

commuter traffic based upon historical levels. Future operational levels of traffic are 

created by growing today’s operations to meet growth rates estimated in different 

forecasts such as the FAA’s 2002 TAF. 

Capacity estimates come from detailed modeling performed in other tools such as the EACM. It is important that in the use of such tools the interaction between improvements 

be properly accounted for. At times various enhancements may provide similar benefits 

under like conditions. If these interactions are not accounted for capacity estimates may 

be too high. By using a network model, such as the one incorporated into this study, 

additional interaction between demand and capacity at a single airport, as well as across 

airports can also be taken into account. 

Capacity-Related Delay Estimates: The benchmark capacities were also used to 

perform a simple estimate of future delay levels. First, historical delay data was obtained 

from the FAA’s Aviation System Performance Metrics9

 (ASPM) database for the top 35 

airports. “Airborne Delay” was used as an estimate of the arrival delay due to capacity at 

the airport, and “Taxi Out Delay” was used as a measure of airport-related departure 

delay. Also calculated was the ratio of annual traffic to an annualized capacity at each 

airport. For future delay estimates, it was assumed that the average delay was 

proportional to this demand/capacity ratio (which simplifies the known exponential 

relationship between capacity and delay). Thus, if the demand/capacity ratio at an airport 

increased by ten percent, future airport-related delay at that airport was also estimated to 

rise by ten percent. 

 

8 Official Airline Guide - Source of flight schedule information. See http://www.oag.com

9

 For more information see: http://www.apo.data.faa.gov 

27
Demand-to-Capacity Ratio for Airports Other Than The Top 35: A simplified 

approach was used for airports other than the top 35. Because ASV estimates did not 

exist for most other airports, and detailed delay modeling was not complete, the approach 

was to compare annualized demand to annualized capacity. In the absence of detailed 

information about these airports, conservative assumptions about fleet mix and operating 

procedures were made, in order to avoid overlooking airports with potential capacity 

problems. The resulting hourly capacities from the E-ACM were annualized based on an 

analysis of weather conditions and an assumed operating day of 12 hours. As additional 

information is obtained through coordination with the individual airports it will be

possible to update this analysis by using a similar approach to that used for the top 35 

airports. 

Selection Criteria for Identifying Capacity Constrained Airports

As discussed earlier the FAA began this task to look across multiple studies and 

determine a common set of airports that each study could agree upon as needing 

additional capacity. Because of the strict commonality requirement, the results of this

assessment should be viewed as a minimal list of airports needing additional future 

capacity. 

Because of the differences in approach and assumptions made in each study used by this 

report, each study had a different set of criteria that it used to indicate an airport may 

need additional capacity. It was only when all the criteria were met that an airport was 

included in the list of common airports. The criteria used by each study are described 

below. 

Top 35 airports 

The information available about, and the knowledge of, the top 35 airports was much 

more extensive than the information about the other airports. Because of this, the criteria 

used for the top 35 airports was much more stringent in this assessment than the criteria 

for the other airports. The need for additional capacity was indicated by: 

• Ratio of annual demand to Annual Service Volume estimated at 0.8 or above 

(demand at least 80 percent of capacity). 

• Arrival delay estimated at 12 minutes per flight or above, on an annual basis. 

• Capacity related delay estimated to exceed 4.5 minutes per flight, or a 

demand/capacity ratio of 0.95 or above (using an annualized capacity based upon 

hourly benchmark capacities in VMC, MMC, and IMC). 

To be identified on the common list of airports it was necessary to satisfy each of the 

three criteria described above, under two different future traffic level assumptions: one 

using the 2002 TAF and the other using the socio-economic information described earlier 

in this section (a total of six criteria). If any of the criteria was not met in either future

demand scenario, then an airport was not included on the common list. Requiring the 

28
criteria to be met using the two different traffic levels provided some level of sensitivity 

analyses around the results. 

Other Airports 

For airports other than the top 35, a Demand-to-Capacity Ratio was approximated using 

annualized hourly capacity estimates obtained from the E-ACM. Future demand 

predicted to be at least 90 percent of available capacity was used to indicate a need for 

additional capacity. As more detailed modeling is done in the future, a similar set of 

criteria to that used for the top 35 airports will be utilized. 

Because a more simplified approach was used for these airports the strict requirement 

that the criteria must be met for both TAF derived demand projections as well as socioeconomic demand projections was not used here. Several of the airports earlier identified 

in this report as needing additional capacity were only identified using the experimental 

model based upon the socio-economic information. On the other hand, all airports 

identified with the TAF demand were also identified using the socio-economic 

information. 

The purpose of the FACT effort is to bring all these studies together in order to develop a 

common list of airports (or associated metropolitan areas) that may need additional 

capacity. If an airport failed to meet any of the individual study’s criteria, then it was not 

identified by the FACT study as a member of the common list of airports needing 

additional capacity. Airports not identified in this analysis may have been identified in 

one or more of the studies, but not in all of them. Because the requirement for 

commonality was so strict, the results of this assessment should be viewed as a minimal

list of airports needing additional future capacity. Simply because an airport was not 

identified in this analysis as needing additional capacity does not mean it should stop 

planning for future capacity improvements. One should not assume that these airports 

will have adequate capacity. 

Process of Identifying Metropolitan Areas Needing Additional Capacity 

As traffic demand continues to grow in the future and airspace congestion is magnified, it 

will become ever more important to look at regional strategies and solutions to solve 

capacity shortfalls. Already today major metropolitan areas with multiple airports in 

close proximity to each other are showing signs of strain on airspace and surface 

congestion. One part of this analysis was to look at metropolitan areas and to determine, 

at a high level, if additional capacity would be necessary in the future. 

Estimating Future Performance

To accomplish an analysis of metropolitan areas, commercial service airports within 

approximately 60 miles of the major population concentrations were identified. Figure 

C-3 provides an example for the Los Angeles Basin. In this example six airports were 

considered in the metropolitan analysis for the Los Angeles Basin: BUR, LAX, LGB, 

ONT, OXR, and SNA. Using a high-level approach, for each metropolitan area the sum

29
total of demand at each airport considered was compared to the sum total of the 

individual capacities of each airport. For the Los Angeles Basin example, that means 

summing up the demand at each of the six identified airports and comparing that demand 

to the sum of capacity at each of the six airports.

 OXR

 LAX

 BUR 

 LGB

 SNA

 ONT 

Figure C-3. LA Basin Metropolitan Analysis Example 

This analysis did not attempt to reallocate traffic among airports within a metropolitan

area and did not explore the feasibility of doing so. In discussions with individual 

airports on the results of this study, they did point out how some movement was possible 

but certain limitations existed. As a next step in this analysis, regional solutions such as 

the reallocation of traffic should be explored. 

Selection Criteria for Identifying Capacity Constrained Metropolitan Areas

If total demand of commercial service airports in the metropolitan area was predicted to 

exceed 80 percent of the available capacity, this was an indication that additional capacity 

may be necessary. For metropolitan areas that consisted of only a single commercial 

airport, a threshold of 90 percent was used (same as the individual airport threshold). 

The lower threshold of 80 percent, being used for the metropolitan areas with multiple 

airports, recognizes that not all available capacity can be used due to increased airspace 

congestion and compensates for the simplified nature of the metropolitan analysis. 

30
Appendix D: The Effect of the Sensitivity Analysis Using the 

FY 2003 Terminal Area Forecast 

In the past several years the aviation industry has undergone a substantial amount of 

change. Changes to the industry that would typically take years to complete have been 

occurring over periods of months or even weeks. As traffic levels fell, older aircraft were 

retired or placed into storage. Fleet mixes at several major airports have changed and are 

continuing to evolve as airlines “right size” to current demand levels (both to smaller 

aircraft and to larger ones as well). Airlines have entered and exited bankruptcy, and 

restructured their operations along the way. Some airports have seen dramatic drops in 

operations as their dominant carriers have pulled out, while others have experienced 

sharp increases in operations. Many carriers have de-peaked their operations and 

transitioned to a “rolling-hub” type of operation. Changes of this type have a major 

impact on the risk of forecasting future traffic levels. 

As changes in traffic predictions are occurring, specific capacity enhancing plans are also 

being revised. These plans are constantly updated in order to align them with current and 

predicted needs, as well as with anticipated funding levels. Changes in the underlying 

assumptions regarding which improvements will be in place, and by when, will impact 

the results of any study. Trying to evaluate the manner in which analytic results may 

change based upon moving targets such as these is difficult, but it is an important part of 

a study such as this one. 

The purpose of this section is to evaluate how the results of this analysis could potentially 

change based upon updated forecasts contained in the newly released 2003 Terminal 

Area Forecast. The focus here will be strictly on the changing demand picture, but 

similar differences may be expected when accounting for changes in future capacity 

enhancement plans. 

Forecasting the future, obviously, is always uncertain. In order truly to understand a 

forecast, it is helpful to understand potential sources of change; that is, things that were 

assumed as part of making the forecast, and how susceptible these assumptions are to 

change in the future. Three potential sources of so-called forecast risk are: 

• the risk that forecasts of underlying explanatory variables may change 

• the risk that a model was incorrectly specified due to inadequate data, and

• the risk of unanticipated structural shocks 

As an example of the first risk, take the estimation of market power of existing carriers. 

This information is calculated using the concentration of dominant and non-dominant 

carriers in O&D markets. Market power plays an important role in determining O&D 

passenger flows, but it is not known how this factor will evolve in the future. A similar 

statement can be made regarding the presence of low-cost carriers in a market. 

Forecast model risk is strongly influenced by assumptions about load factors and fleet 

mix. Recent examples of this can be seen when comparing traffic demand estimates in 

31
the 2002 TAF and the 2003 TAF releases. For example at SFO, the 2002 TAF estimates 

2013 traffic demand levels at 385,538 operations, while the 2003 TAF estimates 2013 

traffic demand levels at 446,791 (a difference of approximately 16 percent more traffic). 

At MDW the 2002 TAF estimates 2020 traffic demand levels at 472,774 operations while 

the 2003 TAF estimates 2013 traffic demand levels at 358,528 (a decrease in traffic 

expectations of approximately 24 percent). The differences in these forecasts were 

caused by changing assumptions underlying the analysis. For example, the differences at 

SFO were caused by assuming a downsizing of aircraft size over time. This means more 

aircraft (and thus operations) are needed to serve the same number of passengers. At 

MDW it was a combination of assuming larger aircraft size and a shifting of the type of 

operations (air carrier, general aviation, and commuter) that would occur at the airport. 

Finally, structural shocks to the system (e.g.; natural disasters, industrial accidents, 

national economic collapse, terrorist incidents) are another area that contributes to the 

uncertainty of a given forecast. For example, a catastrophic event may change the overall 

demand situation and invalidate a particular model of the system. As with most forecasts, 

the forecasts used by this analysis do not anticipate and incorporate structural shocks that 

may occur in the future, as they are by definition unpredictable. 

When looking at total demand at the top 35 airports in 2013, the 2003 TAF differs little 

from the 2002 TAF. The 2002 TAF predicted a total of 19,338,535 operations to occur in 

2013 at the top 35 airports. The 2003 TAF predicts traffic levels of 19,330,276 at the 

same airports; or 99.96 percent of the previous forecast. This difference is very small and 

inconsequential. The difference in 2020 predictions follows the same pattern, with the 

2003 TAF predicting 99.95 percent of the operations forecast in the earlier TAF. 

Although the differences in total operations at the top 35 airports between one TAF and 

the other is very minor, that is not the case when you look at individual airports. Specific 

airport differences can be significant (see Table D-1). 

Table D-1. Summary of Forecast Differences: 2002 TAF and 2003 TAF 

2013 2020 

At least 10 percent higher

in 2003 TAF 

SFO - 16% 

ORD - 15% 

LAS - 10% 

SFO - 19% 

ORD - 18% 

LAS - 12% 

At least 10 percent lower

in 2003 TAF 

STL – 29% 

MDW – 14% 

STL – 32% 

MDW – 24% 

CLE – 10% 

MIA - 11% 

With such dramatic changes between forecasts, one would expect the results of a study 

based upon these forecasts to differ. To understand better how the results of this study 

could potentially change, a series of sensitivity analyses was performed. Several of the 

32
criteria used to indicate a need for additional capacity outlined in the section on scope 

and methodology reevaluated in light of the new forecast. No assessment was made to 

the magnitude of the individual difference; an evaluation was made simply to see if 

additional airports might be identified as needing additional capacity, or if airports 

currently identified may no longer indicate a need for additional capacity.

The specific approach used is as follows: 

• First Step: a reevaluation of the ASV at each airport was performed to see if the 

ASV criterion outlined in the section on scope and methodology was met. If not, 

and the airport was previously identified as needing additional capacity, then it 

was noted as an airport that would no longer have such a need. If the criterion 

was met, step two was performed. 

• Second Step: a reevaluation of the capacity related delay and annualized 

demand/capacity ratio criteria was performed (see section on scope and 

methodology). If neither criterion was met, the airport would not be identified as 

needing additional capacity and could potentially fall off the common list (if

previously shown). If either one of these criteria were met then the third step was 

performed. 

• Third Step: the change in forecast was compared to the arrival delay estimates 

previously calculated. Potential levels of delay given the new forecast were 

calculated by extrapolating changes in delay given changes in demand. This is 

only a rough order estimate as it only accounts for changes at the airport and not 

the system wide impact captured by the modeling effort. In addition, the larger 

the difference in forecast, the more inaccurate such an approach becomes. 

However, it provides one level of sensitivity analysis until further modeling can 

be performed. If the new estimated level of delay meets the criteria specified in 

the scope and methodology section, then the airport would be identified as 

needing additional capacity. 

If all the criteria outlined above in all three steps are met by an airport, it is considered an 

airport that potentially needs additional capacity based upon the 2003 TAF. If any of the 

criteria is not met, then the airport is not considered to have a need for additional 

capacity. The results were then compared to the findings of this study based upon the 

detailed assessment using the 2002 TAF and the socio-economic information. The 

approach used here as a sensitivity study should provide insight into how the study results 

could potentially change. The results presented here are preliminary. Detailed modeling 

of operations at each airport, using the 2003 TAF, has not yet been completed. However, 

the preliminary differences between the results are discussed below. 

33
Preliminary Evaluation of Changes to the 2013 Results

When performing an analysis that assumes the improvements outlined earlier in the 

document for 2013, the sensitivity study of the 2003 TAF indicates little change from the 

2002 TAF findings (see Figure D-1). These results show that one additional airport 

(LAS) may be considered as needing additional capacity due to much faster growth 

expectations. At the same time, one airport previously identified as needing additional 

capacity (LGB) may no longer be included in the common list of airports. 

1 new airport that may be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

1 airport that may no longer be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

1 airport that may no longer be identified

as needing additional capacity

Figure D-1. 2013: Potential Change in Analysis Results Using 2003 TAF 

(After Assumed Improvements) 

When performing an analysis that does not assume improvements to capacity above 

today’s current levels, the sensitivity study of the 2003 TAF does not show any additional 

airports that need additional capacity in 2013. On the other hand, six airports (BWI, 

LAX, LGB, MDW, PHX and STL) would no longer meet the criteria for needing 

additional capacity (see Figure D-2). All of these airports are predicted to have fewer 

operations than predicted in the 2002 TAF. The change in MDW’s forecast and the 

reason for such a change was discussed earlier in this section. The dramatic fall in 

operations at STL over the last year, as a major air carrier reorganized its operations, has 

been incorporated into the 2003 TAF. These results indicate a need to continually 

monitor changes to the forecasts and to periodically update associated analyses. 

34
No new airports to be identified

as needing additional capacity

No new airports to be identified 

as needing additional capacity

6 airports that may no longer be identified

as needing additional capacity

No new airports to be identified

as needing additional capacity

No new airports to be identified 

as needing additional capacity

6 airports that may no longer be identified

as needing additional capacity

Figure D-2. 2013: Potential Change in Analysis Results Using 2003 TAF 

(If Planned Improvements Do Not Occur) 

Summary of Potential Changes to 2013 Results 

Table D-2 summarizes how the 2013 results of this study could potentially change based 

upon updated forecasts contained in the newly released 2003 Terminal Area Forecast. 

Table D-2. Summary of Potential Changes to 2013 Results 

2013 

Improvements

2013 

No Improvements 

New Airports Meeting Criteria for 

Needing Additional Capacity LAS None

Airports No Longer Meeting Criteria 

for Needing Additional Capacity LGB 

BWI 

LAX 

LGB 

MDW 

PHX 

STL 

35
Preliminary Evaluation of Changes to the 2020 Results

When performing an analysis that assumes the improvements outlined earlier in the 

document for 2020, the sensitivity study of the 2003 TAF does not show any additional 

airports that need additional capacity in 2013. On the other hand, two airports (ISP and 

MDW) would no longer meet the criteria for needing additional capacity (see Figure 

D--3). Both of these airports are predicted to have fewer operations than predicted in the 

2002 TAF. The change in MDW’s forecast and the reason for such a change was 

discussed earlier in this section. ISP’s forecast predicts 16% fewer operations in 2020 

than the 2002 TAF prediction. 

No new airports to be identified

as needing additional capacity

No new airports to be identified 

as needing additional capacity

2 airports that may no longer be identified

as needing additional capacity

No new airports to be identified

as needing additional capacity

No new airports to be identified 

as needing additional capacity

2 airports that may no longer be identified

as needing additional capacity

Figure D-3. 2020: Potential Change in Analysis Results Using 2003 TAF 

(After Assumed Improvements) 

When performing an analysis that does not assume improvements to capacity above 

today’s current levels, the sensitivity study of the 2003 TAF shows one additional airport 

would be considered as needing additional capacity in 2020 (SFO). At the same time, 

four airports (ISP, MDW, MIA and STL) would no longer be considered in need of 

additional capacity (see Figure D-4). 

36
1 new airport that may be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

4 airports that may no longer be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

1 new airport that may be identified

as needing additional capacity

4 airports that may no longer be identified

as needing additional capacity

Figure D-4. 2020: Potential Change in Analysis Results Using 2003 TAF 

(If Planned Improvements Do Not Occur) 

Summary of Potential Changes to 2020 Results 

Table D-3 summarizes how the 2020 results of this study could potentially change based 

upon updated forecasts contained in the newly released 2003 Terminal Area Forecast. 

Table D-3. Summary of Potential Changes to 2020 Results 

2020 

Improvements 

2020 

No Improvements

New Airports Meeting Criteria for Needing 

Additional Capacity None SFO

Airports No Longer Meeting Criteria for 

Needing Additional Capacity 

LGB 

MDW 

ISP 

MDW 

MIA 

STL 

37
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