Decarbonizing Aviation Ground Operations 2025

Landside buses operate outside the security perimeter and are primarily responsible for transporting passengers, staff and occasionally crew between airport terminals, car parks, public transport hubs and other non-restricted areas. These services are integral to ensuring smooth access and connectivity across airport infrastructure for arriving and departing passengers. Conversely, airside buses function within the secure area of the airport, facilitating the transfer of passengers, crew and ground staff between terminal buildings and aircraft stands. Given the necessity to synchronize precisely with aircraft turnaround times and boarding procedures, airside bus operations are subject to stringent safety and operational requirements. The configuration and complexity of both airside and landside operations vary significantly with the airport’s operational profile. This affects the number of buses operating at airports. For instance, in large hub airports with multiple terminals, high passenger volumes can require extensive landside bus networks to manage inter-terminal traffic and ensure efficient passenger flow. An example is Dubai International Airport (DXB), which served more than 92 million passengers in 2024:2 its 200-strong airside bus fleet transferred over 16,000 passengers per month on average.3 In contrast, intermediate and regional airports may rely on more modest bus fleets, typically ranging between 10 and 20 units. However, these regional airports are usually constrained by gate infrastructure and may host high volumes of low- cost carrier traffic that often prefers bus-to-stand operations, to maximize rapid aircraft turnaround and cost-efficiency over the use of gates, which can be more limited and expensive to operate. Operating hours at airports, often dictated by legislative restrictions, also impact bus operations. Airports with 24-hour schedules require continuous bus availability and maintenance. On the other hand, airports under night-operating restrictions may plan their activities in a different manner. These restrictions affect maintenance costs, bus lifespans, staffing needs and refuel scheduling. Airport ownership is a factor to consider for preparing a decarbonization strategy and accessing funding sources. Ownership models (private or state) may vary depending on region.4 Approaches to decarbonization can differ depending on the ownership model: government-funded airports often operate within the framework of national or regional policies, whereas privately owned airports may have greater flexibility to define strategies according to their operational or market context.Airports’ path to emissions-free bus operations could be significantly influenced by the underlying business strategies that emerge from different airport ownership models, but also from the bus ownership models directly. At a fundamental level, three dominant categories prevail (see Figure 2): direct ownership of bus fleet and operation by the airport authority; outsourced provision through concession agreements; and third-party contracts and hybrid approaches combining both.1.2 Bus fleet ownership models Decarbonizing Aviation Ground Operations: Alternative Bus Technologies 6