This Report describes the evaluation and development of emission models for non-exhaust particulate matter (PM). The PM sources covered are three abrasion processes - tyre wear, brake, road surface wear - and the resuspension of road dust. For the abrasion sources the evaluation focussed on the EMEP, RAINS, CEPMEIP and MOBILE6.2 methods. The EMEP method was considered to be the most advanced approach, and was considered to be the most suitable for application in the UK (it is already used in the National Atmospheric Emissions Inventory). The lack of a substantial amount of new source-specific emission factors in the literature meant that no further developments of the abrasion models were possible. Emissions due to resuspension were estimated for Marylebone Road in London, based on PM10 and PM2.5 measurements and the application of different models for the abrasion sources. The results suggested that resuspension accounts for 43-49% of total non-exhaust emissions, and resuspension emissions were found to be around 30% of the magnitude of exhaust emissions. Emission factors for resuspension due to HDVs ranged from 139 mg/vkm to 145 mg/vkm. Much lower emission factors were observed of LDVs. The estimates of abrasion emissions appeared to be quite sensitive to the method adopted. The study has shown that there are few detailed methodologies for predicting emissions of particulate matter from non-exhaust sources. There is clearly a need for more extensive empirical data, and a number of general recommendations for methods of obtaining such data are made. One weakness of the study is that it is based purely on a single street canyon site, and it is important to test the extent to which the results can be generalised to other locations having different characteristics.

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