# 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. *** ### **Sample API Requests** #### A. Without audit mode (for pre-booking/quotes) ```json { "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) ```json { "expand": ["items"], "audit_for": "", "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. *** ### **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"`).\ \&#xNAN;*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**. *** ## 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: * `:` (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** ```jsonc // 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. *** ### **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. *** ### **Sample API Response** ```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). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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