Why Is It So Hard to Build an Airport?

Airports are a critical piece of modern infrastructure. Aviation contributes an estimated 8% to global GDP through direct and indirect effects (ie: the businesses and commerce that it enables), and an estimated 25% of companies’ sales rely on air transport. In 2022, civil aviation in the US flew over 850 million passengers, generated more than a trillion dollars in economic activity, and was responsible for most long-distance inter-city trips. All this was made possible by 550 commercial airports, the largest 50 of which handle more than 80% of air traffic.¹

Despite their importance, airports are enormously difficult to build, not only in the US but around the world. Airport construction is nearly always vigorously opposed by various interest groups, often successfully. As air travel greatly expanded in the 1960s and 70s, there were “no more virulent domestic conflicts… in the advanced industrial world than those over airport construction.” In her history of US airports in the second half of the 20th century, Janet Bednarek notes that building a new airport was so “extraordinarily difficult…that very few completely new major commercial airports were constructed." Of the 50 largest airports in the US, the average age is 82 years, and only three have been built in the last 50 years. The US has built more commercial nuclear reactors in the past 25 years (two) than it has major commercial airports (none), even though air travel increased by almost 50% over that period.

“Major” means annual traffic exceeding 1 million passengers per year. Via FAA, Wikipedia.

What makes it so hard to build an airport? And how has the US managed to accommodate increased air travel in spite of this difficulty? Let’s take a look.

Jet aircraft and the beginnings of modern air travel

Commercial air travel has been around since 1914, but for most of its early history airplanes were a niche mode of transportation, compared to trains or ships. It wasn’t until 1955 that more people traveled in the US by air than by train, and 1957 that air travel surpassed sea travel across the Atlantic Ocean. It was the invention of the jet airliner that transformed air travel into the ubiquitous mode of transportation that it is today. Boeing’s 707 first flew in 1957, followed shortly by the Douglas DC-8, and by 1963 air travel miles in the US exceeded both railroads and buses combined. Between 1955 (shortly before the first jet US airliners debuted) and 1985, air travel in the US increased from just over 40 million annual passengers to more than 400 million.

This enormous increase in air traffic driven by jet airliners required greatly expanding civil aviation infrastructure. Not only did airports need to be enlarged to handle the rise in passengers and aircraft moving through them, but jet airliners required much longer runways to take off and land than propeller planes did. Lockheed’s Constellation, a 4-engine propeller airliner which entered service in 1943, needed a 6000 foot-long runway, but the Boeing 707 needed more than 10,000 feet at full takeoff weight, as did the Boeing 747 which followed 10 years later. In 1957 an American Airlines executive stated that not a single airport the company flew to could fully accommodate the new jets, either because of insufficient runway length or insufficient terminal facilities. Many believed that the new jet airliners would require their own special “jetports” built specifically to accommodate them.

Expanding aviation infrastructure to handle jets proved difficult. The most important reason was noise. Residents near airports had long complained about the noise from planes: in 1948, when what would become JFK International opened, residents from 18 civic organizations protested the noise from low flying planes. But noise from jet aircraft proved to be a much more severe problem. The Air Force jets under development in the 1950s were expected to be “the loudest man-made industrial noise up to now.” And while tests of commercial jet aircraft showed that they weren’t necessarily noisier than comparable prop airplanes (tests comparing the 707 to the Lockheed Constellation measured similar noise levels), the high-pitched frequencies of jet engine noise were discovered to be far more disturbing to human ears than piston engines were. And because of the longer takeoff and landing distances, a jet airliner would expose many more people to noise than a piston engined aircraft.

Relative annoyance of different aircraft at different decibel levels. To be comparably disturbing to piston engines, the early jet engines had to be 15 decibels quieter. Via Link.

Noise levels at different distances of different transportation modes. Via Politics of Airport Noise.

Early on, it was hoped that people would simply get used to the sounds of jet airliners, and accept them as the price of progress. In 1961, the FAA put out a pamphlet, “The Sounds of the 20th Century,” aimed at explaining why jet engines made noise, and emphasizing the many benefits that air transportation brought, in the hopes that understanding would breed acceptance. When questioned about aircraft noise by a US congressman in 1962, the head of the FAA stated that “we feel the statement that people must live with noise is realistic in the light of our growing society using complex means of transportation and communication. Noise in urban America is one of the prices paid for progress and economic growth."

But despite these hopes, it was clear to most that jet noise was a serious problem, with the “potential to impede air commerce in the USA”. A year after the introduction of the first commercial jets, congressional hearings were held on aircraft noise problems, and the following year the FAA acknowledged that the introduction of jet airliners had led to “a substantial increase in the number of complaints from persons in the airport environment, as well as adverse community reaction to turbojet noise at a number of major airports.” Jet noise became such a problem at LAX that appraisals for property values near the airport dropped as much as 20%

Jet airliners were also introduced during a time when citizens were increasingly skeptical of progress at any cost, and of the decisions made by unaccountable government technocrats. Opposition to airports was joined by opposition against highway construction, dams, nuclear reactors, and other technology and infrastructure that activists felt was misdirected progress. Noise began to be considered another harmful pollutant by the burgeoning environmental movement. 

Citizens increasingly filed lawsuits against airports for damages, in some cases even attempting injunctions to stop the use of jets. In 1961, 800 homeowners in Queens sued the Port Authority for $2 million in damages from aircraft noise, though the suit was ultimately discontinued for lack of funds. In 1966, one irate housewife threatened to blow up JFK’s aircraft control tower. The FAA was so concerned about reactions to jet noise in Washington DC that it didn’t authorize jets to land there until 1966. In response to political pressure, jet noise bills were continually introduced in congress, and in 1968 a bill was passed that authorized the FAA to include noise levels as part of its criteria for certifying new aircraft.

By the time the FAA bill passed, technology was already helping to solve the noise problem. The first generation of jet airliners used turbojet engines, in which air enters the engine, gets compressed, burned, and is exhausted out at supersonic speed. It was this supersonic exhaust which created the lion’s share of jet engine noise. But in the late 1950s, a new type of jet engine was developed, the turbofan. Unlike the turbojet (where all the air enters the combustion chamber and is burned) a turbofan has a large fan mounted to the front that pulls air into the engine but around the combustion chamber (because this air bypasses the combustion chamber, turbofans are also called bypass engines). The turbofan extracted much more energy from the hot exhaust of the combustion chamber, leading to a colder exhaust stream. Not only was this more fuel efficient (jet engines are most efficient when the speed of their exhaust matches the cruising speed of the aircraft), but they were much quieter than turbojets. By 1961, turbofans had replaced turbojets on all new commercial jets. 

And while turbofans were being developed, NASA was conducting research on technologies that could be used to quiet jet engines, such as redesigned engine nacelles and fan blades. As a result of this technology and research, and of slowly increasing stringency of FAA noise regulations after 1968, the noise of jet engines steadily fell.

Airliner noise over time. Via “Aircraft Noise Technology For The 21st Century.”

But the decreasing noise of individual jet engines was partially offset by continuously rising jet traffic. In 1960, just 16 airports in the US had jet service; by 1970, that had risen to more than 300. Between 1962 and 1970, the number of jet aircraft used by US airlines rose by a factor of five. And the more passengers on a jet, the harder the engines had to work, and the more noise they made.

Despite improvements from turbofans and other technology, complaints against jet noise showed no signs of abating. In the two years after jets were introduced at National Airport (now Ronald Reagan) in Washington DC, the FAA received more than 6000 letters from angry citizens. By 1968, LAX was facing three billion dollars in lawsuits over jet noise. By 1972, noise in the US (much of it jet related) generated more complaints than “any other pollutant or threat to the environment,” and experts worried that “violent civil disobedience at airports [was] a real possibility in the near future.” In the mid-1970s, millions of people were exposed to average aircraft noise levels exceeding 65 decibels (the level at which noise is the “most important adverse aspect of the environment”), and airports around the country were facing hundreds of millions of dollars in lawsuits.²

Besides improving engine technology, other solutions to the noise problem could likewise only partially address the issue. Airports could route planes over less inhabited areas, but there was often limited ability to do this. At JFK, for instance, the Port Authority tried to limit takeoffs to runways which faced over the water, but this wasn’t possible if traffic was high enough or winds weren’t favorable. Airports could also mandate takeoff and landing procedures that minimized noise impact, such as “low altitude, reduced power climbs, [and] higher angles of descent," but pilots resisted many of these, claiming they were unsafe. Reduced noise procedures were thought to be responsible for at least one crash at JFK.

Legal rulings and federal government policy also constrained how airports and municipalities could address problems of aircraft noise. Courts had established that exposing a property to aircraft noise constituted a “taking” that required compensation (dating from a 1946 case in which low-flying military jets caused a farmer's chickens to kill themselves as they ran into the walls in fright). And they had also established that airport owners were responsible for the noise that they generated. But even as the courts assigned responsibility for noise to airports, they greatly restricted what airports could do about it. Airport rules that limited night takeoffs and landings, for instance, were often overturned, with courts ruling that air traffic fell under the jurisdiction of the FAA. Zoning rules near airports that might limit noise exposure were also often struck down as not beneficial to the general public. And though airports lobbied for a federal noise abatement policy (in part to reduce their own liability), the government resisted, and the FAA carefully structured its aircraft noise rules to avoid taking any responsibility for implementing noise restrictions.

Ultimately airports were left with little choice but to install soundproofing in residences near airports, and to acquire parcels of land via eminent domain that were too affected by noise. This often resulted in airports buying hundreds or even thousands of homes in adjacent areas and demolishing them. LAX, for instance, bought and demolished the entire town of Surfridge. By the 1980s, airports around the country were spending $100 million per year on noise abatement, most of which went towards acquiring land parcels.

Over time, FAA noise standards have gotten more stringent, noisier aircraft have gradually been phased out, and aircraft noise has steadily decreased. But tolerance for noise seems to be falling faster, and by most accounts airport noise continues to be the most important issue limiting airport construction.

Decline of population exposed to noise levels over time, via NAS.

Ideally, the noise problem would be solved simply by building an airport far from any heavily populated areas. But this has also proved difficult. While some airports, such as Chicago’s Midway, Boston Logan, and New York’s LaGuardia were built close (or even within) the cities they served (before jets made such construction infeasible), many others were built far from the city, only to have the city eventually expand around it. O’Hare (which began as an aircraft factory for Douglas Aircraft in WWII) was originally built on farmland relatively far from Chicago, but post-war sprawl pushed development outward, and by the late 1960s O’Hare had some of the most severe noise problems in the country. Denver International Airport was likewise deliberately built far from Denver on an enormous empty plot of land in a partially successful attempt to minimize noise issues.

And an airport can’t be too far from a city and remain useful, since travelers need to access the city, workers need to be within commuting distance, and so on. In Canada, Mirabel airport was built 35 miles from Montreal, surrounded by a 79,000 acre buffer zone to prevent any issues of incompatible land use. Mirabel was expected to replace Dorval (today Montreal-Trudeau) as Canada’s main eastern airport, but, in part because of its long distance from the city, this never happened, and Mirabel stopped serving passenger traffic in 2004.

In addition to the noise problem, this sheer size of airports makes building them near cities difficult. Though early airfields were often small (when Chicago Midway opened, it took up just 80 acres, and by the 1950s it was the busiest airport in the world on 650 acres of space), a modern airport needs thousands of acres. Runways are two miles or more in length, and require thousands of feet of space between them to allow simultaneous landing of planes. This, along with the additional land needed to be acquired as a noise buffer, means that airports are “the largest land using facilities on the urban periphery,” often the size of a city in their own right. In the early 1980s, Dallas Fort-Worth Airport covered as much land as the city of Dallas did, and Denver International Airport is as large as the city of San Francisco. In addition to the difficulty of finding this much space, an airport perversely both creates demand for more housing (for the workers, along with whatever increase in commerce the airport causes) while removing thousands of acres of space for it.

The noise problem means that building a new airport is strongly resisted by local residents. But residents aren’t the only ones opposing airport construction. They’re also fought by environmentalists. In addition to the noise they generate, the size of airports means building one will encroach on what might be ecologically valuable areas such as forests or wetlands, damaging them even if they’re just used for a noise buffer (the risk of bird strikes means that the ideal airport is one surrounded by “sterilized fields” where birds aren’t inclined to nest). The huge amount of jet fuel that flows through an airport creates the risk of leaks and spills. Decades of fuel spills at JFK resulted in a “vast lake of jet fuel” beneath the airport, anywhere from 5 million to 9 million gallons in size.

Environmental opposition has thus been a major factor in limiting airport construction. Environmental groups like the Sierra Club have opposed new airports at Palmdale in California and near Minneapolis in Minnesota. Environmental opposition stopped both the expansion of JFK (which would require filling in portions of Jamaica Bay) and the construction of a new fourth airport in the New York region. It stopped a small training facility near the Everglades from becoming the largest airport in the world. Environmental opposition to airports has been greatly aided by the passage of the National Environmental Policy Act (NEPA) in 1969: NEPA has been leveraged to oppose, among other things, the construction of the Denver International Airport, and the expansion of Oakland, Anchorage, and O’Hare airports.

New airport construction is also often resisted by airlines themselves, which have invested significant money in their terminal facilities at existing airports. Similarly, where airlines have a “fortress hub” (an airport whose traffic is mostly captured by a single airline), they will often resist new airports as a threat to their dominance. Delta, for instance, opposed the construction of a new airport in Atlanta that would have been used by Southwest Airlines.

The factors that make it hard to build a new airport also make it hard to expand an existing airport. Often, urban encroachment means an airport has no feasible room to grow, like at Chicago’s Midway and New York’s La Guardia. If it is possible to expand, such expansion will invariably be protested vigorously by residents and environmental groups. Protest against expansion of JFK by filling in Jamaica Bay has kept the airport at roughly the same size since it was first built in 1948. The construction of an additional runway at Boston Logan was successfully resisted for over 30 years, and a new runway at Sea-Tac was resisted for 16 years. Local and environmental opposition prevented the expansion of LAX in the late 1990s. Chicago had such a difficult time overcoming opposition to expanding O’Hare that it asked the federal government to force such an expansion through legislation. A GAO report found that, on average, it took 10 to 15 years for a US airport to complete a new runway. 

And airports around the world don’t seem to fare much better. Heathrow in London has been trying for more than 50 years to add a third runway. And while between 2008 and 2016, the 4000+ commercial airports around the world added around 400 new runways, zero runways were added at the top 100 airports by traffic (which handle roughly half of all air travel).

Via GAO.

Their enormous size, along with their noise and other negative environmental impacts, makes a new airport the ultimate in NIMBY (not-in-my-backyard) infrastructure: people are fine with having an airport, but will fiercely resist having an airport built near them. Most NIMBY difficulties stem from the asymmetric nature of the costs and benefits of a new project: a new apartment building, for instance, will benefit a city overall (slightly lowering housing costs and slightly increasing the size of the city’s labor market), but those benefits are diffuse. The costs, on the other hand – traffic, parking, construction disruption – will be borne almost entirely by the surrounding residents, who will thus rationally oppose it.

An airport pushes this dynamic to the extreme. The disruption to the immediate area is immense, due to the size of the airport and the negative impacts of noise, not to mention the increased traffic that an airport generates. The benefits, on the other hand, are diffuse. While the region and state benefit from the economic activity the airport generates, many of the benefits of an airport accrue to the entire country, in the form of a better functioning aviation system, with fewer delays to passengers nationwide. Expanding capacity at O’Hare might reduce congestion at other hubs far from the city of Chicago. Similarly, not only are many of the users of an airport tourists who don’t live in the area, but at hub airports they might merely pass through without interacting with the local region at all. 

Unlike much other US infrastructure, modern, large airports that serve commercial jets only became needed as the environmental movement gained steam and building things in general became hard. Thus, building a major commercial airport has always been difficult: there has never been a "golden age of airport building."

Strategies for increasing air traffic

Given the difficulty of building or expanding airports, how has the US (and other countries) managed to steadily expand the volume of air traffic without catastrophic congestion? 

For one, despite the difficulty, airports have been able to add new runways. Between 2000 and 2015, 21 of the busiest airports in the country added 18 runways and extended 7 runways. This is important, as an additional runway brings more capacity gain than any other sort of airport improvement. Airports have also rebuilt their infrastructure to squeeze more capacity without needing any additional land area. Airports such as JFK, Atlanta-Hartsfield, and O’Hare, for instance, have removed cross-runways and added parallel runways to allow for simultaneous landing of aircraft, increasing the volume of aircraft the airport can handle. Airports have also been able to build more terminals and more gates, and added technologies like jetways, automatic baggage handlers, and people movers that move people through the airport faster.

Evolution of runway layout at JFK over time. Via The Metropolitan Airport

An important measure of airport capacity is “plane movements” – how many takeoffs and landings an airport can support over a period of time. This is typically limited by runway capacity. But even if no runways are added and the number of plane movements remains fixed, capacity can be increased by raising the number of passengers per plane. Many airports, for instance, created policies to discourage general aviation aircraft, freeing up room for higher-capacity commercial planes. In 1968 the New York Port Authority greatly increased the landing fees for small aircraft, which resulted in general aviation traffic declining by 30% over the next few months. This was followed by the FAA imposing quotas on general aviation traffic at five major airports, which had a similar effect.

Similarly, commercial aircraft have steadily gotten larger over time. In the 1960s, international routes were limited to the Boeing 707 or the DC-8, which had a maximum capacity of 174 and 269 passengers respectively, but the 1970s saw the introduction of the Boeing 747 which initially could seat 366 passengers. And besides introducing new, larger models, individual models also got larger over time: stretching an aircraft to get more passengers has long been a strategy for aircraft builders. When the 737 was first introduced, it had a capacity of up to 130 passengers. Today, a 737-MAX10 can have up to 230 passengers. And average aircraft capacity seems to still be rising: between 2000 and 2016, average seat capacity on flights around the world increased by 31%. Airlines have also gotten better at filling their aircraft to capacity. In 1970, commercial aircraft were on average just 49% full. Today, that has risen to more than 80%. These all increase the number of passengers transported per airplane, and thus allows more passenger volume from the same number of runways.

As airports have become congested, traffic has often shifted towards other airports that have more capacity. Inability to add capacity has caused Boston Logan to begin redirecting traffic to other, regional airports. This sort of shift is often facilitated by the hub-and-spoke network of US air travel: since the hub isn’t the final destination, it's often possible for airlines to shift routes to go through different hubs if one becomes congested. As O’Hare became congested, for instance, some airlines shifted routes to other hubs at St. Louis and Denver.

Finally, capacity can be increased by changes in air traffic control and how planes are routed. Significant congestion issues at European airports in the late 1980s were resolved by improvements to the air traffic control system. In the US, the NextGen air traffic control program was created to expand air transportation capacity, which does things like researching wake turbulence to see if required aircraft separation distances can be safely reduced. Similarly, airport congestion often only occurs at limited peak hours, and capacity can be increased by shifting flights to non-peak hours (though airline resistance might make this difficult).

One benefit that airports do have for increasing capacity is that, unlike many other aspects of the air transportation system, they’re very profitable. Airports have “extremely high credit ratings” (Fitch lists several major airports as having various levels of “A” credit), and can easily finance their expansion via issuing bonds. So financing airport infrastructure is a comparatively smaller problem than it is for things like mass transit.

Nevertheless, the air travel system seems to be constantly bumping up against its capacity limits, especially in places like New York which have high traffic and limited ability to expand. Severe flight delays occurred across the country in the late 60s, the late 1980s and the late 1990s. Airbus, in fact, based its development of the enormous A380 on the expectation that limited airport capacity meant that airlines would have no choice but to use fewer, larger planes. (The fact that this didn’t happen, and airlines instead chose to buy thousands of smaller aircraft like the 737 MAX, apparently successfully, is something I don’t quite understand.)

Conclusion

Air travel is an interesting dichotomy. On the one hand, building the infrastructure for it is unbelievably difficult. Airports are incredibly hard to build, aircraft are incredibly hard to make a profit selling, airlines are frequently going bankrupt. And yet this hasn’t stopped air travel from steadily becoming cheaper, safer, more convenient and more ubiquitous. The pre-jet era, when aircraft and airports could be developed without spending billions of dollars, was also the era where air travel was noisy, inconvenient, and reserved for a relatively small number of people. It was somehow brought to the masses, transformed from a miracle to a modern convenience even as every aspect of it steadily got closer and closer to being impossible to achieve.

If you’re interested in reading more about airport building, a reading list of the major sources I found useful is available here for paid subscribers.

1. The US has almost 20,000 airports, but the majority of these are small, private airstrips that don’t handle commercial traffic.

2. More specifically a Day-Night Average sound level (DNL), which averages sound over a 24-hour period, with additional weighting given to sounds at night.