5 Airports Where A Single Runway Closure Can Bring An Area's Operations To A Standstill

Published Sep 2, 2026, 1:00 AM EDT Brandon's passion for aviation started at a young age. He became involved in the flight simulator and VATSIM communities, which sparked his interest in aviation and eventually led him to earn his private pilot license. Outside of work, he continues to build flight hours, explore new airports, and stay involved in the aviation community. Most major commercial airports operate with two or more runways, which allows them to maintain operations when one runway is closed for maintenance, inspections, or incidents. If a runway at Dallas/Fort Worth International Airport (DFW) shuts down, the airport has six others. If a runway at Atlanta Hartsfield-Jackson (ATL) closes, four remain. The impact is manageable because the infrastructure provides redundancy. Not every airport has that margin. Several of the world's busiest airports operate with a single runway or, in Mumbai's case, two intersecting runways that can only be used one at a time. At these airports, any closure of the active runway halts all operations with no fallback. The five airports on this list handle between 25 million and 45 million passengers annually on a single active runway. They include the busiest single-runway airports in the United States, Europe, and the world. Some have second runways under construction or approved. Others have replacement airports planned for the next decade. San Diego International Airport (SAN) 25.2 million passengers per year Credit: Shutterstock San Diego International Airport (SAN) is the busiest single-runway commercial airport in the United States. Runway 09/27 measures 9,401 feet (2,865 meters) and handles every arrival and departure at an airport that served a record 25.24 million passengers in 2024. The airport sits 3 miles (5 km) northwest of downtown San Diego, bordered by San Diego Bay to the south, the Marine Corps Recruit Depot to the north, Interstate 5 to the east, and residential neighborhoods on the approach path to the west. There is no room for a second runway. Discussions about adding one have surfaced periodically since the 1960s, but the physical constraints have prevented every proposal from advancing. Southwest Airlines holds the largest market share at SAN with nearly a third of all passengers. Alaska Airlines operates a hub at the airport. United, Delta, American, JetBlue, and a dozen other carriers serve over 70 nonstop destinations, including international routes to London, Tokyo, Frankfurt, and several Mexican and Canadian cities. The new Terminal 1 opened its first phase in late 2025, adding 19 gates. The second phase will demolish the remaining original 1967 terminal and add 11 more gates by 2028. The terminal investment addresses passenger processing capacity but does not change the runway constraint that defines the airport's operational ceiling. A closure of runway 09/27 at San Diego shuts down commercial aviation for the entire San Diego metropolitan area, a region of 3.3 million people. The nearest commercial alternatives are Tijuana's General Abelardo L. Rodríguez International Airport (TIJ) across the Mexican border and John Wayne Airport (SNA) in Orange County, approximately 80 miles (129 km) to the north. Neither can absorb San Diego's traffic volume. Xiamen Gaoqi International Airport (XMN) 29.2 million passengers per year Credit: Shutterstock Xiamen Gaoqi International Airport (XMN) is the busiest single-runway airport in China, handling 29.19 million passengers and 198,582 aircraft movements in 2025 on a single 11,155 foot (3,400 meters) runway. The airport sits on the northeastern tip of Xiamen Island in Fujian Province, approximately 7.5 miles (12 km) from central Xiamen. It serves as the main hub for XiamenAir and a focus city for China Eastern Airlines, Shandong Airlines, and Spring Airlines, connecting over 100 domestic and international destinations across China, Southeast Asia, and Europe through two terminals, T3 and T4. The airport's island location makes expansion impossible. The runway is bordered by water, urban development, and existing terminal infrastructure on all sides. China has five single-runway airports handling over 20 million passengers annually, located in Xiamen, Sanya, Harbin, Shenyang, and Urumqi. Xiamen is the busiest of the five by passenger volume. Any closure of the single runway for maintenance, weather, or an incident halts all operations at the primary international gateway for southeastern Fujian Province and one of China's most important coastal economic zones. Unlike the other airports on this list, Xiamen is not waiting for a second runway or a long-term expansion plan. The airport will close entirely in late 2026 when Xiamen Xiang'an International Airport opens on Dadeng Island, approximately 16 miles (25 km) from central Xiamen. The replacement airport will have two parallel runways in its first phase with capacity for 45 million passengers annually, and a long-term plan for four runways and 75 million passengers. Gaoqi will cease all civilian operations when the transition is complete, ending 43 years of single-runway service on Xiamen Island. Lisbon Humberto Delgado Airport (LIS) 35.1 million passengers per year Credit: Shutterstock Lisbon Humberto Delgado Airport (LIS) is Portugal's primary international gateway, the main hub of TAP Air Portugal, and a major base for Ryanair and easyJet. In 2024, the airport handled 35.1 million passengers on a single runway designated 03/21, measuring 12,484 feet (3,805 meters). That figure exceeded the airport's designed capacity of approximately 34 million, making it the busiest single-runway airport in mainland Europe. The airport sits 4.3 miles (7 km) northeast of central Lisbon in an urban area surrounded by residential neighborhoods, with between 300,000 and 380,000 residents in Lisbon and nearby Loures reporting sleep disruption and health issues from aircraft noise. A runway closure at Lisbon does not redirect traffic to an alternative airport in the same city. There is no second airport serving the Lisbon metropolitan area. Porto's Francisco Sá Carneiro Airport (OPO) is 190 miles (306 km) to the north. Faro Airport (FAO) is 165 miles (266 km) to the south. Neither can absorb Lisbon's traffic volume or serve as a hub for TAP's connecting network. Any disruption to runway 03/21, whether from maintenance, an incident, or weather, halts all operations at the airport that handles the majority of Portugal's international air traffic. Portugal has been planning a replacement airport for decades. The current proposal, named Luís de Camões Airport, would be built at the Alcochete military firing range on the south bank of the Tagus River at an estimated cost of €7.9-8.9 billion. The government's most recent timeline targets construction beginning in 2029 and an operational opening between 2035 and 2037. Until then, ANA, the airport operator, is investing approximately €400 million in interim upgrades to increase the current airport's throughput to 45 flights per hour. The single runway that serves as Portugal's primary air link to the world will remain the only option for at least another decade. London Stansted Airport (STN) 30 million passengers per year Credit: London Stansted Airport London Stansted Airport (STN) handled a record 30 million passengers in 2025 on a single runway designated 04/22, measuring 10,000 feet (3,049 meters). The airport is Ryanair's largest base in the world, with the Irish low-cost carrier connecting over 150 destinations from the Essex airport located 42 miles (68 km) northeast of central London. Jet2 and TUI also maintain bases at Stansted, and Turkish Airlines launched service to Istanbul in March 2026. The terminal, designed by Foster + Partners and opened in 1991, is undergoing a £1.1 billion expansion including a £600 million terminal extension to increase capacity. In December 2025, Uttlesford District Council approved raising Stansted's annual passenger cap from 43 million to 51 million over the next 20 years. Manchester Airports Group, the airport's owner, stated that the increase would be achieved using larger aircraft on the same number of flights rather than by building a second runway. A proposal for a second runway was submitted in 2008 and officially withdrawn in 2010 after political opposition and a Competition Commission review. No plans for a second runway exist today. A closure of Stansted's single runway would disrupt Ryanair's operations at a scale that no other single airport closure could match. Ryanair operates more flights from Stansted than from any other airport in its network, and many of those routes are served exclusively from Stansted with no alternative London departure point on the same carrier. Passengers could rebook through London Gatwick (LGW), Luton (LTN), or Heathrow (LHR), but none of those airports have the spare capacity to absorb Stansted's traffic on short notice, particularly during the summer peak when all four London airports operate near capacity. The airport that is growing toward 51 million passengers has one runway to handle all of them. London Gatwick Airport (LGW) 45 million passengers per year Credit: London Gatwick Airport London Gatwick Airport (LGW) is the busiest single-runway airport in Europe, handling approximately 280,000 flights and over 45 million passengers per year on a main runway designated 08R/26L measuring 10,879 feet (3,316 meters). Gatwick technically has a second runway, the northern standby runway 08L/26R, but it sits too close to the main runway for simultaneous operations and is used only when the main runway is temporarily closed for maintenance or emergencies. Switching from one runway to the other takes approximately 15 minutes, during which no aircraft can land or depart. For practical purposes, Gatwick operates as a single-runway airport. The UK's second busiest airport serves as a major base for easyJet, British Airways, Norse Atlantic, and Wizz Air, connecting over 200 destinations. Gatwick is the primary London airport for long-haul leisure traffic to the Caribbean, Southeast Asia, and Africa, and handles a significant share of London's short-haul European traffic. Spare slots at peak periods are scarce, and the runway is utilized at rates that leave almost no margin for disruption. A relatively minor incident, a burst tire, a runway inspection, or a weather delay that temporarily closes the runway, can cascade through the day's schedule within minutes because there is no second active runway to absorb the backlog. In August 2026, the UK government approved Gatwick's plan to bring the northern standby runway into regular use by relocating it 12 meters (39 feet) further north to meet international safety standards for simultaneous operations with the main runway. The project, estimated at £2.2 billion, would add approximately 100,000 flights per year and increase capacity to 75-80 million passengers by the late 2030s, with the northern runway expected to begin operations by 2030. Until then, every flight at the UK's second-busiest airport continues to use a single strip of pavement, and any closure of that runway halts operations for an airport that handles more passengers annually than most four-runway airports in the world.