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 factorsEmission factor Site Methodology Refrence

8 mg/vkm Stockholm city Brake 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=0.7-2.5 um Lab Garg et al., 2000

MMD=6 um Sanders 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 = 50-100 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 factorsEmission factor Site Methodology Reference

4 mg/vkm Stockholm, 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