New method of calculating emissions from tyre and brake wear and road abrasion

In the current project, the SIMAIR model system was used to develop a new method to estimate non-exhaust PM emissions from road traffic in Sweden.

In 2014, the Swedish emission factors used for particulate matter from road abrasion were reviewed as a consequence of remarks made by the Swedish Transport Administration (STA) regarding PM2.5 emission factors for studded tyres. The review resulted in revised emission factors from road abrasion, and it also concluded that Sweden should base its estimates from tyre and brake wear and road abrasion on a more robust model that also takes meteorology into account. In the current project, the SIMAIR model system was used to develop a new method to estimate non-exhaust PM emissions from road traffic in Sweden. The new methodology takes into account several factors that have not been considered in previous estimates, such as meteorology, regional variations and measured PM10 concentrations in urban street canyons for model verification.Annual emission factors for PM10 were obtained for eight different regions covering all of Sweden for the years 2008-2014. The average emission factors per region vary between 120 mg/km in southern Sweden and 200 mg/km in region Öst (eastern Sweden). The resulting emissions are generally somewhat higher than previous estimates.The new method is considered to substantially improve the quality of the Swedish non-exhaust PM emission estimates. The method can be further improved when the NORTRIP model has been implemented in SIMAIR, and by automatizing the method to enable annual updates of the emission factors that are representative for more road links.

NV DiVA SMED Report No 177 2015