Train: DEFRA 🇬🇧

💡 High-Level Description:

DEFRA (Department for Environment, Food & Rural Affairs) provides essential conversion factors and guidelines for calculating greenhouse gas (GHG) emissions across various sectors, including passenger rail services. As one of the main references for emissions reporting in the UK, DEFRA’s methodology ensures consistency, transparency, and accuracy when assessing the environmental impact of train travel.

The methodology focuses on direct emissions from train fuel combustion and indirect emissions associated with electricity consumption. DEFRA distinguishes between electric and diesel-powered trains, accounting for varying levels of emissions based on fuel type, train type (e.g., national, international, light rail), and distance traveled. DEFRA's framework is widely used in corporate GHG reporting, providing essential data for understanding the carbon impact of train travel and supporting efforts to reduce emissions.

Versioning: Add methodology_version to pin a specific DEFRA Conversion Factors year (e.g., "2024"). If omitted, SQUAKE uses the latest supported year.

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Sample API Requests

A. Without audit mode (for pre-booking/quotes)

{
  "expand": ["items"],
  "items": [
    {
      "audit": false,
      "type": "train",
      "external_reference": "test_1",
      "origin": "BER",
      "destination": "FRA",
      "number_of_travelers": 3,
      "train_type": "national",
      "methodology": "DEFRA",
      "energy_scope": "ttw",
      "methodology_version": "2024"
    }
  ]
}

B. With audit mode (for finalized/post-booking calculations)

{
  "expand": ["items"],
  "audit_for": "<Auditable Entity ID>",
  "items": [
    {
      "audit": true,
      "type": "train",
      "external_reference": "test_1",
      "origin": "BER",
      "destination": "FRA",
      "number_of_travelers": 3,
      "train_type": "national",
      "methodology": "DEFRA",
      "energy_scope": "ttw",
      "methodology_version": "2024"
    }
  ]
}

Note: audit_for is optional. Provide when calculating on behalf of a specific Auditable entity; otherwise omit.

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API Request Items

• "type": "train" (required)

• "methodology": "DEFRA" (required)

• "methodology_version": DEFRA Conversion Factors year (e.g., "2024"). Optional; if omitted → latest supported year.

• "external_reference": Unique identifier to link the result (max 128 chars).

• "number_of_travelers": Minimum 1. Default: 1.

• "origin" / "destination": Flexible formats (postal, IATA/ICAO ^[A-Z]{3,4}$, UN/LOCODE ^[A-Z]{2}\W?[A-Z2-9]{3}$, or "lat,lon"). Distance is auto-resolved.

• "distance_in_km": If provided, overrides origin/destination.

• "train_type": Supported categories (per DEFRA): "national", "international", "light", "tram", "underground".

• "energy_scope": "wtw" (default) or "ttw".

• "audit": boolean (optional). Set to true to create immutable audit records for finalized calculations. Must be enabled for your account.

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Origin/Destination Formats (Enriched)

SQUAKE will try to resolve the origin/destination regardless of its format. Ideally:

• Addresses: Use the Post standard.

• Airports: Use IATA/ICAO code (regex: ^[A-Z]{3,4}$, e.g., "MUC").

• Ports/Trade locations: Use UN/LOCODE (regex: ^[A-Z]{2}\W?[A-Z2-9]{3}$, e.g., "DEHAM").

• Coordinates: Pass latitude/longitude (regex: ^[-+]?\d{1,3}\.\d{1,10}\s?,\s?[-+]?\d{1,3}\.\d{1,10}$, e.g., "+40.712,-74.006").

UIC and Provider Codes for Trains

• UIC code is also a valid format for trains. If the value is not valid, the system will fallback to general, non-journey-specific emission data.

• When you want to use a UIC or provider code, use the following format:

  • <provider>:<uic_code> (e.g., 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

Examples

// Using UIC/provider code
{
  "type": "train",
  "methodology": "DEFRA",
  "origin": "atoc:1072",         // Example UK station code structure
  "destination": "atoc:5935",
  "number_of_travelers": 1,
  "energy_scope": "wtw",
  "methodology_version": "2024"
}

// Using UN/LOCODEs (for multimodal contexts)
{
  "type": "train",
  "methodology": "DEFRA",
  "origin": "GBLON",             // London
  "destination": "GBMAN",        // Manchester
  "number_of_travelers": 1
}

// Using coordinates
{
  "type": "train",
  "methodology": "DEFRA",
  "origin": "+51.503,-0.125",    // London
  "destination": "+53.480,-2.242",// Manchester
  "number_of_travelers": 1
}

Notes

• If both origin/destination and distance_in_km are provided, distance_in_km is used for emissions.

• Invalid, unsupported, or unresolvable location codes will trigger a fallback to generic (non-journey-specific) factors consistent with the DEFRA methodology.

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Default Values

• "train_type": "national"

• "energy_scope": "wtw"

• "methodology_version": latest supported DEFRA year

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Sample API Response

{
  "carbon_quantity": 6669,
  "carbon_unit": "gram",
  "items": [
    {
      "carbon_quantity": 6669,
      "carbon_unit": "gram",
      "external_reference": "test_2",
      "type": "train",
      "methodology": "DEFRA",
      "methodology_version": "2024",
      "distance": 435.0,
      "distance_unit": "kilometer"
    }
  ]
}

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Versions

• Behavior: If methodology_version is omitted, SQUAKE automatically applies the latest supported DEFRA Conversion Factors year. Pin a year for reproducibility and audit readiness.

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Bibliography

• UK Government — Greenhouse gas emissions: Research & statistics: https://www.gov.uk/environment/greenhouse-gas-emissions#research_and_statistics

• DEFRA (2024). Government Greenhouse Gas Conversion Factors for Company Reporting (Rail factors).

• UK Office of Rail and Road. National Rail Trends.

• Eurostar. GHG Methodology Report.