Enhancing Airport Access with Emerging Mobility (2025)
Chapter: 13 Intra-airport Mobility
CHAPTER 13
Intra-airport Mobility
Introduction
While this report mostly concerns access to and from the airport environment, some of these technologies can also facilitate ground movement within the airport perimeter. As airports expand, several scenarios can emerge where walking is no longer feasible nor comfortable:
- Elongated terminal buildings can require guests and airport employees to walk long distances between gates. This can be challenging for passengers who are making tight connections, especially for passengers with reduced mobility (PRMs), children, or heavier luggage, unless a people mover or similar is provided.
- Terminal-satellite configurations exist in various sizes and shapes. They are usually linked to the main terminal (processor) via an underpass (tunnel) or a bridge. Skybridges (e.g., at Seattle-Tacoma International Airport [SEA] and New Terminal B at LaGuardia Airport [LGA]) are practical over short distances, but these are more of an exception than a rule.
- Interterminal transfer might be necessary if passengers are self-connecting at airports with separate passenger-terminal facilities (flying on multiple reservations with different air carriers) or if an air carrier’s (or its partner’s) operations are not consolidated within the same facility.
- Off-terminal consolidated rental car (CONRAC) and ground transportation center (GTC) facilities have been implemented at airports. These facilities do not necessarily need to be adjacent to airport terminals, and real estate around the curbside might not be needed to meet future demand, especially at legacy airport facilities. Access to mass transit, rental cars, or parking garages can require shuttling to and from the airport terminal.
Analyzing and Selecting Intra-airport Mobility Solutions
Walking long distances is detrimental to the airport experience; it can make the difference between passengers being able to board or missing their flights. It is also a matter of accessibility for passengers with mobility impairment. Airport Development Reference Manual (ADRM), 12th Edition, by the International Air Transport Association (IATA) (2022) specifies that passengers’ maximum acceptable walking distance between gates should not exceed 985 feet unaided. If moving walkways are provided, the maximum acceptable walking distance increases to 2,133 feet. For distances beyond that, mass mobility mechanisms, such as buses or automated people movers (APMs), should be offered. Assuming an unaided walking speed of 200 feet per minute, or 2.3 miles per hour (mph), the maximum acceptable travel time is approximately 5 minutes. If a moving walkway is used, the maximum acceptable travel time increases to 7 minutes, assuming a travel speed of 320 feet per minute (3.6 mph).
These specifications have been determined by taking passenger comfort into consideration and accounting for passengers who find it difficult or impossible to cover long distances in short time spans (e.g., people with reduced mobility or other disabilities and travelers with small children). The ADRM specifically recommends that APMs be used for distances beyond 2,460 feet as long as peak-hour demand is greater than 3,000 passengers per direction per hour. APMs can deliver higher throughputs and provide other benefits (e.g., speed and automation).
Figure 87 provides a visual tool that illustrates the travel time ranges associated with the three modes most suitable for intra-airport mobility—moving walkways, buses, and APMs—as well as the ADRM’s walking distance recommendations, which can help airport planners determine the need and feasibility of deploying any of these ground access technologies. Travel time ranges can also be used to help determine the spacing between moving walkways and the headway between shuttle buses and APMs.
Ease and cost of implementation should be considered as well when choosing how to establish intra-airport mobility alternatives. Decision-making should consider both the initial investment and operating and maintenance (O&M) costs for such systems. For instance, the APM at Los Angeles International Airport (LAX), scheduled to enter service in 2023, cost $2 billion to design and build—or $800 million per dual track mile. However, it is the centerpiece of the landside redevelopment at this airport, unlocking and connecting much-needed land off
Source: Lea+Elliot et al. (2010), adapted by WSP
Note: pax/d/hr = passengers per direction per hour.
Table 40. Benefits and Drawbacks of Different Modes for Intra-Airport Mobility
| Mobility Mode | Benefits | Drawbacks |
|---|---|---|
| Walking | No additional costs or implementation needed. | Walking for prolonged time periods or distances might be uncomfortable or even unfeasible for some guests, especially those with reduced mobility. |
| Moving walkways | Small footprint; assists pedestrian mobility. | Insufficient for larger or longer terminals; O&M costs and operations. |
| Shuttle bus | Can run on existing apron; provides mass transport over longer distances. | Less frequent service than with APMs; needs adequate vehicle service roads. |
| APM | Frequent transport of large passenger volumes at fast speeds. | Higher implementation cost (built above or below terminal corridors). |
the highly congested curbside area that will accommodate new gateways to the airport (CONRAC, bus station, etc.).
Table 40 compares a selection of modes and technologies in the context of intra-airport mobility.
Passenger Conveyance Inside Terminals
The use of airside buses for movement within a terminal structure is rare. APMs are generally used at longer terminal buildings; they have been implemented either as part of a terminal’s initial design (e.g., ExpressTram, built at Detroit’s McNamara Terminal in 2002) or consolidation (e.g., Skytrain, built at Miami’s North Terminal in 2010). Both the Detroit and Miami terminals are nearly a mile long, with passengers otherwise required to walk unaided for up to 25 minutes. Terminal 1 at Kansai International Airport (KIX) near Osaka, Japan—the longest terminal in the world at 1.1 miles—uses two Wing Shuttle APM lines, one per wing. Within terminals with lower peak-hour affluence where passengers might need to walk long distances, moving walkways are commonly used instead.
Terminal-Satellite Transfer
Since satellite terminals and concourses are detached structures, often entirely surrounded by the airfield, they can accommodate more aircraft gates than similarly sized conventional terminal structures, making them attractive to airport planners. These satellites can be hundreds of feet from their terminals—such as LGA’s Terminal B and Terminal A at Boston Logan International Airport (BOS)—or beyond a mile away, as with Hartsfield–Jackson Atlanta International Airport (ATL) and Washington Dulles International Airport (IAD). Satellites in the former category often require no more than an elevated or underground walkway (with or without moving walkways) for passengers to travel between them and their terminals while adhering to the IATA recommendations on walking time.
Both buses and APMs can be deployed to connect terminals and satellites across longer distances, and the same peak-hour demand criteria should be used to determine which mode would be most suitable for each terminal-satellite combination. APMs can run aboveground (e.g., Orlando and Tampa) or underground (e.g., ATL and IAD) and require significant infrastructure investments. Bus systems can provide versatile terminal-satellite mobility and can be used either
as the primary mode or as an alternate while walkways or APM infrastructure are under construction or maintenance. In a unique example, the “mobile lounge” concept, pioneered at IAD in the 1980s, is similar to a bus, but it can also be raised and lowered to dock with aircraft and terminal gates. The mobile lounge is still being used to shuttle passengers between Concourse D and other piers until the APM system is fully built.
Interterminal Transfer
Mobility between two airport terminals might also be required. This can be due to passengers self-connecting in different terminals of the same airport, which would require them to exit the secure area, collect and recheck their baggage, and then proceed through security controls at the second terminal. Interterminal transfer might also be necessary to access other ground transportation modes: While Orlando International Airport’s new Terminal C has a direct connection to the Brightline high-speed rail station, passengers departing from or arriving at Terminals A and B would need to transfer to Terminal C to access it.
Unlike intra-terminal and terminal-satellite mobility, interterminal transfer often occurs outside of the secure area, which provides airport operators and metropolitan planning organizations (MPOs) with additional options. Interterminal transfers can be provided by the airport for free using shuttle buses, as at St. Louis Lambert International Airport between Terminals 1 and 2, or through APMs, such as the John F. Kennedy International Airport (JFK) AirTrain. Mass transit operators can also offer intra-terminal transfers as part of a broader transit line, with free 24-hour service offered between airport terminals. At Minneapolis-St. Paul International Airport, Metro Transit allows ticket-free riding between the Terminal 1 and Terminal 2 stations of the Blue Line LRT.
Following the consolidation of U.S. full-service carriers into the “Big Three,” the same airline or its partners can end up operating out of multiple terminals. At Philadelphia International Airport, American Airlines operates out of Terminals A-West, A-East, B, C, and F, whereas at JFK in New York, Delta used to divide its operations between Terminal 2 (closed in January 2023) and Terminal 4. Due to the terminals’ design, transferring between them would not be possible without exiting and re-entering the secure area; airlines and airports have instead implemented airside shuttle bus systems to facilitate these transfers entirely within the secure area, with conditional access for passengers holding a boarding pass for a flight departing from a different terminal.
To and From Off-Site Ground Transportation Facilities
Passenger conveyance goes beyond the airport’s terminals. The most common example of this concerns accessing not only ground transportation, garages, and rental car facilities but also other non-transport amenities, such as hotels and convention centers. Due to space constraints near airport terminal buildings at larger airports, these facilities might not be adjacent to the terminal, and they may require shuttling services.
Who offers the shuttles and the types of ground access modes used are dependent on what types of services are connected to the airport. Private parking and rental car companies with off-site lots—which can be more economical than airport garages—will often deploy their own shuttle services to transport customers after dropping off their cars and before picking them up. Conversely, if the airport provides off-site lots—such as economy or overflow parking—it will operate its own shuttles. When an off-site facility is part of the airport’s multimodal strategy, such as Miami International Airport’s multimodal hub or the Amtrak station at Baltimore/Washington International Thurgood Marshall Airport, the airport or transit providers can provide this service. Corridors with elevated passenger flow can be serviced by an APM instead.
