Train: EPA 🇺🇸

💡 High-Level Description

The US EPA GHG Emission Factors Hub provides passenger-rail emission factors used for corporate greenhouse gas (GHG) accounting in the United States. For trains, factors are expressed as gCO₂e per passenger-kilometer and include CO₂, CH₄, and N₂O aggregated using the EPA’s 100-year GWPs for the given Hub year. In this implementation:

• Units: gCO₂e/pax-km

• Scope: well-to-wheel (WTW) representation of emissions reflected in EPA’s factors

• Coverage: intercity (national average & route-specific), commuter rail, and transit rail

Note on versions: If methodology_version is omitted, SQUAKE will always use the latest supported EPA Hub year. Pinning is recommended for reproducibility.

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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",
      "distance_in_km": 500,
      "number_of_travelers": 1,
      "methodology": "US-EPA",
      "train_type": "intercity_national_average"
    }
  ]
}

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",
      "distance_in_km": 500,
      "number_of_travelers": 1,
      "methodology": "US-EPA",
      "train_type": "intercity_national_average"
    }
  ]
}

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": "US-EPA" (required)

• "methodology_version": EPA Hub year (e.g., "2023"). Optional. If omitted, the calculation defaults to the latest supported year.

• "external_reference": Your unique identifier for correlating responses. Max length 128 chars.

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

• "distance_in_km": Preferred distance input. If both distance_in_km and origin/destination are given, distance_in_km is used.

• "origin" and "destination" (optional): If provided, SQUAKE will resolve the rail distance. Accepts IATA/ICAO/UNLOCODE/postal formats or "lat,lon" (e.g., "+40.712,-74.006"). Note: For EPA factors, the train type should match U.S. service classes (see below).

• "train_type": Supported

  • "intercity_northeast_corridor"

  • "intercity_other_routes"

  • "intercity_national_average"

  • "commuter_rail"

  • "transit_rail"

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

Defaults

• "train_type": "intercity_national_average"

• "number_of_travelers": 1"

• If "methodology_version" is omitted → latest supported EPA Hub year.

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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., atoc:1072 or amtrak:NYP as illustrative code styles)

• 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 a provider code (illustrative; US context)
{
  "type": "train",
  "methodology": "US-EPA",
  "origin": "atoc:1072",          // Example code structure
  "destination": "atoc:5935",
  "number_of_travelers": 1,
  "train_type": "intercity_national_average"
}

// Using UN/LOCODEs (for multimodal contexts)
{
  "type": "train",
  "methodology": "US-EPA",
  "origin": "USNYC",              // New York City
  "destination": "USWAS",         // Washington, DC
  "number_of_travelers": 1,
  "train_type": "intercity_northeast_corridor"
}

// Using coordinates
{
  "type": "train",
  "methodology": "US-EPA",
  "origin": "+40.750,-73.993",    // Near NYC Penn Station
  "destination": "+38.897,-77.007",// Washington, DC
  "number_of_travelers": 1,
  "train_type": "intercity_northeast_corridor"
}

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 US-EPA methodology.

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Computation

Let EF be the factor in gCO₂e/pax-km for the chosen train_type and methodology_version (or latest if omitted).

total_gCO2e = EF × distance_in_km × number_of_travelers

All outputs are returned in grams by default.

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Sample API Response

{
  "carbon_quantity": 18127.337,
  "carbon_unit": "gram",
  "items": [
    {
      "carbon_quantity": 18127.337,
      "carbon_unit": "gram",
      "external_reference": "test_case_1",
      "type": "train",
      "methodology": "US-EPA",
      "distance": 500.0,
      "distance_unit": "kilometer",
      "train_type": "intercity_northeast_corridor"
    }
  ]
}

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Bibliography

• US EPA. GHG Emission Factors Hub (Passenger Rail). https://www.epa.gov/climateleadership/ghg-emission-factors-hub