Train: US-EPA 🇺🇸

Calculate US passenger rail emissions with factors from the US EPA GHG Emission Factors Hub, by US service class, in grams of CO₂e per passenger-kilometre.

type trainmethodology US-EPASupports audit mode

About the methodology

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 in gCO₂e per passenger-kilometre and include CO₂, CH₄ and N₂O, aggregated with the EPA's 100-year GWPs for the given Hub year. In this implementation:

Units: gCO₂e/pax-km.
Scope: tank-to-wheel (TTW). EPA's factors cover combustion emissions only, without upstream (well-to-tank) emissions.
Coverage: intercity (national average and route-specific), commuter rail and transit rail.

Versions

If methodology_version is omitted, SQUAKE always uses the latest supported EPA Hub year. Pinning a year is recommended for reproducibility.

Sample requests

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",
    "external_reference": "test_1",
    "distance_in_km": 500,
    "number_of_travelers": 1,
    "methodology": "US-EPA",
    "train_type": "intercity_national_average"
  }]
}

audit_for is optional

Pass the ID of an auditable entity when you calculate on behalf of that entity. Otherwise, leave it out.

Defaults

Field	Default	Applies when
`train_type`	`intercity_national_average`	No `train_type` is sent
`number_of_travelers`	`1`	No `number_of_travelers` is sent
`methodology_version`	Latest supported EPA Hub year	No `methodology_version` is sent

How it's calculated

Total emissions (gCO₂e)EF × distance × travellers

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

Distance

distance_in_km, the trip distance in kilometres.

Travellers

number_of_travelers.

All outputs are returned in grams by default.

Request fields

typestringrequired

train

methodologystringrequired

US-EPA

methodology_versionstring

EPA Hub year, for example "2023". If omitted, the calculation defaults to the latest supported year.

external_referencestring

Your unique identifier for correlating responses. Up to 128 characters.

number_of_travelersinteger

Minimum 1. Defaults to 1.

distance_in_kmnumber

The preferred distance input. If you send both distance_in_km and origin/destination, SQUAKE uses distance_in_km.

originstring

If provided, SQUAKE resolves the rail distance. Accepts IATA/ICAO, UN/LOCODE or postal formats, or "lat,lon" (for example "+40.712,-74.006"). See Origin and destination formats. For EPA factors, the train type should match US service classes.

destinationstring

Same formats as origin.

train_typeenum

Supported: "intercity_northeast_corridor", "intercity_other_routes", "intercity_national_average", "commuter_rail", "transit_rail".

auditboolean

Set to true to create immutable audit records for finalised calculations. Must be enabled for your account.

See every field of POST /v2/calculations in the API reference

Origin and destination formats

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 codes

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 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.

// 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"
}

Distance and fallback

If you send both origin/destination and distance_in_km, SQUAKE uses distance_in_km for emissions.
Invalid, unsupported or unresolvable location codes trigger a fallback to generic (non-journey-specific) factors consistent with the US-EPA methodology.

Sample response

200 OKapplication/json

{
  "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"
  }]
}

Bibliography

US EPA. GHG Emission Factors Hub (Passenger Rail).

Train: US-EPA 🇺🇸

About the methodologyCopy Anchor Link

Sample requestsCopy Anchor Link

DefaultsCopy Anchor Link

How it's calculatedCopy Anchor Link

Request fieldsCopy Anchor Link

Origin and destination formatsCopy Anchor Link

UIC and provider codesCopy Anchor Link

Sample responseCopy Anchor Link

BibliographyCopy Anchor Link

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