Independent report

2012 emission curves for use in transport modelling and appraisal

The 2012 version of the vehicle emission curve calculations which are used in the national transport model for NOx, PM10, fuel consumption and CO2.

This publication was withdrawn on

The 2012 emission curves have been replaced by the 2017 emission curves.


National transport model: vehicle emission curves

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The speed-emission factor curve calculations used in the national transport model. The curves have been updated with the latest speed-related emission and fuel consumption equations for different vehicle classifications, originally published June 2009.

The calculations relate emission factors, for the air pollutants NOx and PM10 in grams per kilometre, to average speed for each main vehicle class. The classes are representative of the Great Britain fleets for 2003 to 2035.

Published 24 January 2012