Train: CO2-emissiefactoren 🇳🇱

Calculate train travel emissions with the Dutch CO2-emissiefactoren factor set, pinned to a published year and to a tank-to-wheel or well-to-wheel energy scope.

About the methodologyCopy Anchor Link

CO2-emissiefactoren is a leading European reference for robust, harmonised CO₂ emission values across sectors, including rail. For train travel, it reflects operational energy, electricity mix, traction efficiency and, where applicable, infrastructure impacts, so results are consistent, comparable and useful for decisions.

VersionsCopy Anchor Link

The factor set is published per year. Set methodology_version (a 4-digit year) to pin a version for reproducible results.

• Omitted on this endpoint: SQUAKE uses the latest supported year. Train items carry no date, so the year is never inferred here. On the Travel Data API, where activities do carry dates, an omitted methodology_version is derived from the trip or activity start date instead.
• A year without its own published set: resolves to the most recent prior year (for example 2024 → 2023).
• A year before the earliest supported set (2020): returns a validation error.

Supported years: 2020, 2021, 2023, 2025, 2026.

Sample requestsCopy Anchor Link

Send a quote before booking, then repeat the call with audit set to true once the booking is final. The body is otherwise identical.

{
  "expand": ["items"],
  "items": [{
    "audit": false,
    "type": "train",
    "methodology": "CO2-EMISSIEFACTOREN-NL",
    "external_reference": "test",
    "train_type": "international",
    "fuel_type": "average",
    "origin": "AMS",
    "destination": "BER",
    "number_of_travelers": 1,
    "energy_scope": "ttw"
  }]
}

DefaultsCopy Anchor Link

Request fieldsCopy Anchor Link

Origin and destination formatsCopy Anchor Link

SQUAKE tries to resolve origin and destination whatever their format. Ideally, use:

• Addresses: the Post standard.
• Airports: an IATA/ICAO code (regex ^[A-Z]{3,4}$, for example "MUC").
• Ports and trade locations: a UN/LOCODE (regex ^[A-Z]{2}\W?[A-Z2-9]{3}$, for example "DEHAM").
• Coordinates: latitude and longitude (regex ^[-+]?\d{1,3}\.\d{1,10}\s?,\s?[-+]?\d{1,3}\.\d{1,10}$, for example "+40.712,-74.006").

UIC and provider codesCopy Anchor Link

A UIC code is also a valid format for trains. If the value isn't valid, the system falls back to general, non-journey-specific emission data.

To use a UIC or provider code, send <provider>:<uic_code>, for example sncf:FRAAA. Possible provider prefixes: uic, uic8_sncf, sncf, sncf_tvs, entur, db, busbud, distribusion, flixbus, cff, leoexpress, obb, trenitalia, trenitalia_rtvt, trenord, ntv_rtiv, ntv, hkx, renfe, atoc, benerail, westbahn.

{
  "type": "train",
  "methodology": "CO2-EMISSIEFACTOREN-NL",
  "origin": "db:8011160",        // Berlin Hbf (example code structure)
  "destination": "db:8000105",   // Frankfurt (Main) Hbf (example code structure)
  "number_of_travelers": 1,
  "energy_scope": "wtw"
}

Sample responseCopy Anchor Link

{
  "carbon_quantity": 10132,
  "carbon_unit": "gram",
  "items": [{
    "carbon_quantity": 10132,
    "carbon_unit": "gram",
    "external_reference": "test",
    "type": "train",
    "methodology": "CO2-EMISSIEFACTOREN-NL",
    "distance": 596.0,
    "distance_unit": "kilometer"
  }]
}

BibliographyCopy Anchor Link

• Lijst emissiefactoren (2025). CO₂-emissiefactoren.
• Milieu Centraal (n.a.). milieucentraal.nl.