Methodology
Zone Model
MCT calculations are based on process zones, not on geographic regions or terminal layouts. Each zone represents a distinct set of transfer procedures and regulatory requirements:
- DOMESTIC_ONLY
- Domestic-to-domestic transfers within a single country. No immigration or customs clearance required.
- SCHENGEN
- Transfers within the Schengen area. No passport control is required; security screening requirements depend on airport configuration.
- EU_NON_SCHENGEN
- EU member states outside the Schengen area (e.g. Ireland, Cyprus). Passport control is typically required.
- INTL_CLEARED
- International transfers with sterile airside transit. No immigration or customs clearance required between flights.
- INTL_UNCLEARED
- Standard international transfers without sterile transit. Immigration and/or customs clearance may be required.
- UNKNOWN
- Processing requirements cannot be reliably inferred from available data. Conservative assumptions are applied.
Policy Modes
Three policy modes adjust calculated MCT values based on different levels of operational risk tolerance:
- Tight (1.00×)
- Minimal buffer. Intended for experienced travelers and airlines with strong on-time performance.
- Normal (1.05×)
- Balanced buffer. Recommended for most passengers and standard operational conditions.
- Conservative (1.15×)
- Extended buffer. Suitable for travelers with checked baggage, families, or uncertain connections.
Safety Margins
Each MCT value is composed of multiple time components that reflect operational reality:
- Walking time: Estimated gate-to-gate or terminal-to-terminal movement time
- Security: Time required for security screening when applicable
- Immigration: Passport control processing time
- Customs: Customs clearance time when applicable
- Safety margin: Base buffer accounting for operational variability
- Risk factor: Additional adjustment for complex or high-variability operations
US Full-Process Logic
Airports in the United States do not provide sterile international transit. All passengers arriving on international flights must clear immigration and customs before continuing to domestic or onward international flights. This process includes baggage reclaim and re-check, resulting in longer minimum connection times.