Emission factors for transport 

Please refer to the guidance notes (either in PDF or within the spreadsheet 'Notes' page) for more information about the datasets provided below.

Emission factorNotes
Fleet Weighted Road Transport Emission Factor 2021 (XLSX)
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 2021 NAEI.
Guidance Note - 2021 (HTML)
Primary NO2 Emission factors for road transport (2023 version) (XLSX) Primary NO2 Emission factors for Road Vehicles: 2023 version Guidance Note (HTML)
Primary NO2 Emission Factors for Aviation and Other Transport Sources - Guidance (PDF)
Vehicle fleet composition projections (Base 2022) (XLSX)
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).
 
Alternative vehicle technology emission factors (PDF)  

Archived versions

These versions have been superseded by the more recent versions above. The factors within them may not be directly comparable with more recent versions due to changes in the methods and raw emission factors used to derive them. Previous versions of the NOx and PM speed-related emission functions from earlier versions of COPERT 5, also COPERT 4v10 and COPERT 4 v8.1 and the Base 2019r, Base 2013 and Base 2011 fleet composition projections are archived here. These were used in previous versions of the Emission Factor Toolkit EFT v10, v8, v6.0 and v5.2.

Emission factorNotes
Fleet Weighted Road Transport Emission Factor 2020 (XLSX) Guidance Note - 2020 (PDF)
Fleet Weighted Road Transport Emission Factor 2019 (XLSX) Guidance Note - 2019 (PDF)
Fleet Weighted Road Transport Emission Factor 2018 (XLSX) Guidance Note - 2018 (PDF)
Fleet Weighted Road Transport Emission Factor 2017 (XLSX) Guidance Note - 2017 (PDF)
Fleet Weighted Road Transport Emission Factor 2016 (XLSX) Guidance Note - 2016 (PDF)
Fleet Weighted Road Transport Emission Factor 2015 (XLSX) Guidance Note - 2015 (PDF)
Fleet Weighted Road Transport Emission Factor 2014 (XLSX) Guidance Note - 2014 (PDF)
Fleet Weighted Road Transport Emission Factor 2013 (XLSX) Guidance Note - 2013 (PDF)
Fleet Weighted Road Transport Emission Factor 2012 (XLSX) Guidance Note - 2012 (PDF)
Fleet Weighted Road Transport Emission Factor 2011 (XLSX) Guidance Note - 2011 (PDF)
Fleet Weighted Road Transport Emission Factor 2010 (XLS) Guidance Note (PDF)
Fleet Weighted Road Transport Emission Factor 2008 (XLS) Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2022 version) (XLSX) Primary NO2 Emission factors for Road Vehicles: 2022 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2021 version) (XLSX) Primary NO2 Emission factors for Road Vehicles: 2021 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2020 version) (XLSX) Primary NO2 Emission factors for Road Vehicles: 2020 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2019 version) (XLSX) Primary NO2 Emission factors for Road Vehicles: 2019 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2018 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2018 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2017 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2017 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2016 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2016 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2015 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2015 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2014 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2014 version Guidance Note (PDF)
Primary NO2 Emission factors for road transport (2013 version) (XLS) Primary NO2 Emission factors for Road Vehicles: 2013 version Guidance Note (PDF)
Primary NO2 Emission Factors (2012 version) (XLS) Primary NO2 Emission Factors for Road Vehicles - 2012 version Guidance (PDF)
NOx speed-related emission functions (COPERT 5) (XLSX)
These factors are currently used in the NAEI (Base 2016) road transport emission projections.  They are also the emission factors incorporated in the Emission Factor Toolkit, EFT v8.0 (2017).
Guidance note on emission degradation method for NOx (PDF)
NOx speed-related emission functions (COPERT 4v10) (XLS)
These factors are currently used in the NAEI (Base 2013) road transport emission projections.  They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v6.0 (June 2014).
Guidance note on emission degradation method for NOx (PDF)
NOx speed-related emission functions (COPERT 4v8.1) (XLS)  
Vehicle fleet composition projections (Base 2019r) (XLSX)
The Base 2019r fleet composition projections data provided in this spreadsheet are mainly consistent with those used in the NAEI (Base 2019r) road transport emission projections for the UK, excluding London. They are the default fleet composition data incorporated in the Emission Factor Toolkit, EFT v10.0 (2020).
 
Vehicle fleet composition projections (Base 2018) (XLSX)
The Base 2018 fleet composition projections data provided in this spreadsheet are consistent with those currently used in the NAEI (Base 2018) road transport emission projections for the UK, excluding London. They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v9.0 (2019)
 
Vehicle fleet composition projections (Base 2016) (XLSX)
The Base 2016 fleet composition projections data provided in this spreadsheet are consistent with those currently used in the NAEI (Base 2016) road transport emission projections for the UK, excluding London. They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v8.0 (2017)
 
Vehicle fleet composition projections (Base 2013) (XLSX)
The Base 2013 fleet composition projections data provided in this spreadsheet are consistent with those currently used in the NAEI (Base 2013) road transport emission projections.  They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v6.0 (June 2014)
 
New vehicle fleet composition projections (Base 2011) (XLS)  
PM speed-related emission functions (COPERT 5) (XLSX)
These factors are currently used in the NAEI (Base 2016) road transport emission projections.  They are also the emission factors incorporated in the Emission Factor Toolkit, EFT v8.0 (2017)
 
PM speed-related emission functions (COPERT 4v10) (XLS)
These factors are currently used in the NAEI (Base 2013) road transport emission projections.  They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v6.0 (June 2014)
 
London Vehicle Fleet Composition Projections (Base 2013 revised in 2018) (XLSX)
This spreadsheet provides fleet composition data specifically for London, as provided by TfL in 2018. They are consistent with those currently used in the NAEI (Base 2019r) road transport emission projections for London. They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v9.0 (2019) and EFT v10.0 (2020) for London. These include the implementation of the Central London ULEZ in 2019.
 
London Vehicle Fleet Composition Projections (Base 2016) (XLSX)
This spreadsheet provides fleet composition data specifically for London, as provided by TfL in 2016. They are consistent with those currently used in the NAEI (Base 2016) road transport emission projections for London. They are also the default fleet composition data incorporated in the Emission Factor Toolkit , EFT v8.0 (2017) for London
 

Page last modified: 13 December 2023