Passenger traffic is the most visible measure of airport performance. It is widely reported, easily understood and useful for tracking changes in demand. Yet an increase in passenger numbers provides limited evidence about whether an airport is becoming financially stronger, operationally more efficient or environmentally more sustainable.
Recent industry data illustrate this distinction. Traffic recovery can coexist with lower real revenue per passenger, insufficient returns on invested capital and substantial investment requirements. Assessing airport performance therefore requires examining how growth translates into value, how resources are used and how benefits and pressures are distributed.
Traffic has recovered faster than revenue
According to ACI World, airports worldwide handled 9.4 billion passengers in 2024, exceeding 2019 levels by 4%. Total airport revenue reached US$194.9 billion but remained 2.1% below its pre-pandemic level in real terms, after adjusting for inflation. Its economic report draws on financial data from 1,086 airports representing approximately 82% of global passenger traffic. aci.aero
These figures support an indicative comparison:
| Indicator | 2019 index | 2024 index |
|---|---|---|
| Passenger traffic | 100.0 | 104.0 |
| Revenue in real terms | 100.0 | 97.9 |
| Implied real revenue per passenger | 100.0 | 94.1 |
Author’s calculation: (97.9 / 104.0) × 100 = 94.1. This approximation uses published aggregate changes and assumes comparable statistical coverage.
The calculation suggests that real revenue per passenger was approximately 5.9% below its 2019 level. It does not imply an equivalent reduction in airport charges, since total revenue includes several activities. It nevertheless illustrates why growth in passenger volume cannot establish improved financial performance on its own.
ACI World also reports a return on invested capital of 6.3% in 2024, below the sector’s weighted average cost of capital. Higher throughput therefore coexisted with returns that remained insufficient relative to the cost of financing airport assets. aci.aero
Financial indicators can move in different directions
Fraport’s results for 2025 provide a concrete example of the importance of using multiple indicators.
| Fraport Group indicator | 2024 | 2025 | Change |
|---|---|---|---|
| Revenue adjusted for IFRIC 12 | €3.89 billion | €4.21 billion | +8.2% |
| EBITDA | €1.30 billion | €1.44 billion | +10.4% |
| Net profit | €501.9 million | €468.1 million | −6.7% |
| Free cash flow | −€674.7 million | €24.4 million | Returned to positive territory |
Figures refer to the entire Fraport Group, rather than Fraport Greece alone. www.fraport.com
Revenue and operating earnings increased, while net profit declined. Fraport attributed the decline primarily to higher depreciation, amortisation and interest effects associated with Lima, alongside a one-off gain that had supported the 2024 comparison. Improved free cash flow also reflected lower investment spending. www.fraport.com
The interpretation depends on the question being asked. Operating profitability, net earnings and the capacity to finance future investment capture different aspects of financial performance. A single measure cannot adequately represent all three.
Investment requirements change the assessment
In January 2026, ACI Europe presented research by Boston Consulting Group estimating that European airports would require €360 billion in investment by 2040. These requirements cover infrastructure development, modernisation, resilience and climate objectives. www.aci-europe.org
This is an estimate of future requirements, rather than expenditure already incurred. Its analytical significance is that current performance must be assessed alongside the resources needed to sustain it.
An airport may report positive earnings while facing substantial future spending to maintain service quality, replace ageing infrastructure or adapt to changing environmental conditions. Conversely, an airport undertaking major investment may experience weaker short-term cash flow while expanding its future capabilities.
Investment timing therefore matters when comparing airports and interpreting annual results.
What should be measured in regional airports?
For Greek regional airports, a broader assessment requires indicators that capture the relationship between traffic, resources, service quality and local outcomes.
| Dimension | Illustrative indicators | Assessment question |
|---|---|---|
| Financial | Real revenue per passenger, operating margin, cash flow | Does activity generate sufficient financial value? |
| Environmental | Total emissions, emissions per passenger, energy and water consumption | How do absolute pressures and resource intensity change? |
| Social | Occupational safety, accessibility, noise exposure | How are workers, passengers and neighbouring communities affected? |
| Operational | Waiting times, reliability, capacity utilisation | Is service quality maintained as demand changes? |
| Seasonality | Peak-month traffic share, winter connectivity | How evenly is activity distributed throughout the year? |
These are proposed assessment indicators, rather than measured findings for particular Greek airports.
For destinations with strong seasonal demand, annual totals can conceal important differences. The same yearly passenger volume may be distributed relatively evenly or concentrated within a short summer peak. These patterns imply different demands on infrastructure, staffing and service provision.
A useful assessment would therefore examine both annual activity and its distribution over time.
Efficiency gains do not necessarily reduce total impacts
Environmental assessment requires particular care when interpreting indicators expressed per passenger.
Consider a hypothetical airport where passenger traffic increases by 10% and emissions per passenger decrease by 5%. Total emissions would still increase by 4.5%:
1.10 × 0.95 = 1.045
The airport would become less emissions-intensive while generating a larger absolute emissions footprint. Both findings are relevant, and they answer different questions.
The same distinction applies to electricity, water consumption and waste. Intensity indicators describe resource use relative to activity. Absolute indicators describe the total pressure associated with that activity.
Meaningful comparisons also require consistent reporting boundaries. Emissions from operations under an airport operator’s control must be distinguished from wider emissions associated with aircraft operations and surface access.
The contribution of multicriteria assessment
Airport performance involves dimensions that may improve at different rates or move in opposing directions. This creates a clear role for multicriteria decision analysis.
PROMETHEE II can combine selected indicators into a comparative ranking under explicit assumptions about criterion importance and preference thresholds. SMAA-2 can examine how ranking positions behave when criterion weights vary, helping assess the robustness of the results.
Their usefulness depends on the quality and comparability of the underlying data. Indicator selection, reporting boundaries, missing observations and differences in airport characteristics require careful treatment. Rankings express relative performance under stated assumptions; they do not establish an absolute certification of sustainability.
The evidence supports a specific conclusion: passenger growth is an insufficient measure of overall airport progress. A fuller assessment must examine the financial value, service quality and social benefits associated with that growth, together with its environmental pressures and infrastructure requirements.
This analysis combines published industry and corporate data at different levels of aggregation. It does not estimate causal relationships or present original empirical findings from the author’s doctoral research.
