Brake and tire wear DATA ”Mass balance” (total transports, turn over, PM size) Lab (Garg et al) Road tunnel (using tracers) Road side (tracers, COPREM, PMF)

Brake wear emission factors Emission factorSiteMethodologyRefrence 8 mg/vkmStockholm cityBrake wear turnover + total transport Westerlund & Johansson ??US EPA (1985) ?Gothenburg, road tunnel PMF?Sternbeck et al 2001 ?Stockholm road tunnel Kristensson et al 1999 MMD= umLabGarg et al., 2000 MMD=6 umSanders et al., 2003 Stockholm, Hornsgatan COPREM using Cu + Sb as indicator Sjödin et al 2009 Wåhlin et al 2006

WEAREM Sjödin et al

Wåhlin et al 2006 NOX = 1.3 g/vkm =>.72/124.3*1.3 = 7.5 mg/vkm for fine fraction

RAINS

See Boulter

EMEP/CORINAIR see Boulter

Boulter Tyre wear – Cars = 100 mg/vkm – HDV = 1000 mg/vkm – PM10 = 10 % (up to 30%) Brake wear – Cars =10-20 mg/vkm – HGV = mg/vkm – 50% becomes airborne – >80% = PM10

What determines brake wear? Vehicle Speed Vehicle type (HDV, LDV…) Brake type Traffic conditions City center Highway

Tire wear emission factors Emission factorSiteMethodologyReference 4 mg/vkmStockholm, Hornsgatan COPREM using Zn as indicator Sjödin et al 2009

What determines tire wear? Vehicle Speed Vehicle type (HDV, LDV…) Tire type Traffic conditions City center Highway Road conditions