Please refer to the guidance notes (either in PDF or within the spreadsheet 'Notes' page) for more information about the datasets provided below.
| Publication Year | Title | Emission factor | Notes |
| 2025 | Fleet Weighted Road Transport Emission Factor 2023 | Fleet Weighted Road Transport Emission Factor 2023
These datasets contain fleet weighted road transport emission factors by vehicle type, for hot exhaust, cold start exhaust, evaporative emissions and tyre and brake wear from the 2023 NAEI. | Guidance Note 2023 |
| 2025 | Primary NO2 Emission factors for road transport 2025 | Primary NO2 Emission factors for road transport 2025 | Primary NO2 Emission Factors for Road Vehicles: 2025 version Guidance Note |
| 2023 | Vehicle fleet composition projections (Base 2022) | Vehicle fleet composition projections (Base 2022)
The Base 2022 fleet composition projections data provided in this spreadsheet are consistent with those used in the 2020 NAEI (Base 2022) road transport emission projections for the UK, excluding London. They are the default fleet composition data incorporated in the Emission Factor Toolkit, EFT v12.0 (November, 2023). | |
| 2013 | Alternative vehicle technology emission factors | Alternative vehicle technology emission factors |
For previous versions of the above data, please see the Data Archive page.