Emissions Factors Toolkit v13.1: User Guide

This road traffic Emissions Factors Toolkit (EFT) user guide has been compiled by Bureau Veritas in the role of Project Manager for the Local Air Quality Management (LAQM) Helpdesk and should be used in conjunction with Version 13.1 of the Toolkit.

The EFT is published by Defra and the Devolved Administrations to assist local authorities in carrying out Review and Assessment of local air quality as part of their duties under the Environment Act 19951. It is of particular interest for use in the assessment of measures implemented as part of LAQM Air Quality Action Plans (AQAPs), and policy interventions on road traffic emissions, such as the Clean Air Zones (CAZs) and other measures, that form part of the UK national plan on compliance with Air Quality Standards. It is a tool that allows users to calculate road vehicle pollutant emission rates for oxides of nitrogen (NOx) and particulate matter (PM - PM10 and PM2.5), for a specified year, road type, vehicle speed and vehicle fleet composition. Greenhouse gas emissions given as carbon dioxide (CO2) exhaust emission rates can also be calculated for petrol, diesel and alternative fuelled vehicles, with additional output provided for calculation of non-exhaust CO2 equivalent (CO2e) emissions related to the charging of electric and plug-in hybrid vehicles.

The purpose of this user guide is to explain in detail the methodology, datasets and assumptions used in the development of the EFT, and to provide guidance on its use. This user guide also consolidates information regarding previous versions of the EFT, their main changes and updates that have occurred over time.