Emission Factor Toolkit (Version 4.2)

A revised version of the emission factor toolkit (EFT) has been issued and is available for download on Defra’s LAQM tools website (http://laqm1.defra.gov.uk/review/tools/emissions.php). The revised version (Version 4.2) allows the use of detailed local vehicle fleet composition data, i.e. it gives the ability to split the traffic into more than just HDV and LDV. It also corrects some minor errors in the way the previous version interpreted some of the national fleet data. Because of these errors, emissions calculated using version 4.2 may be slightly different from those calculated using version 4.1. Any discrepancies will very small, particularly in relation to other modelling uncertainties. Local Authorities are not required to redo any work already carried out using version 4.1 but are advised to use version 4.2 for future work. Version 4.2 will soon be accompanied by a user guide which will explain how to use the new functions.