Abstract. In order to identify and quantify key species associated with non-exhaust emissions and exhaust vehicular emissions, a large comprehensive dataset of particulate species has been obtained thanks to simultaneous near-road and urban background measurements coupled with detailed traffic counts and chassis dynamometer measurements of exhaust emissions of a few in-use vehicles well-represented in the French fleet. Elemental carbon, brake-wear metals (Cu, Fe, Sb, Sn, Mn), n-alkanes (C19-C26), light-molecular-weight polycyclic aromatic hydrocarbons (PAHs; pyrene, fluoranthene, anthracene) and two hopanes (17α21βnorhopane and 17α21βhopane) are strongly associated with the road traffic. Traffic-fleet emission factors have been determined for all of them and are consistent with most recent published equivalent data. When possible, light-duty- and heavy-duty-traffic emission factors are also determined. In the absence of significant non-combustion emissions, light-duty-traffic emissions are in good agreement with emissions from chassis dynamometer measurements. Since recent measurements in Europe including those from this study are consistent, ratios involving copper (Cu∕Fe and Cu∕Sn) could be used as brake-wear emissions tracers as long as brakes with Cu remain in use. Near the Grenoble ring road, where the traffic was largely dominated by diesel vehicles in 2011 (70 %), the OC∕EC ratio estimated for traffic emissions was around 0.4. Although the use of quantitative data for source apportionment studies is not straightforward for the identified organic molecular markers, their presence seems to well-characterize fresh traffic emissions.

<p><strong>Abstract.</strong> In order to identify and quantify key-species associated with non-exhaust emissions and exhaust vehicular emissions a large comprehensive dataset of particulate species has been obtained thanks to simultaneous near-road and urban background measurements coupled with detailed traffic counts and chassis dynamometer measurements of exhaust emissions of a few in-use vehicles well-represented in the French fleet. Elemental Carbon, brake-wear metals (Cu, Fe, Sb, Sn, Mn), n-alkanes (C19–C26), light molecular weight PAHs (Pyrene, Fluoranthene, Anthracene) and two hopanes (17α21βNorhopane and 17α21βhopane) are strongly associated with the road traffic. Traffic-fleet emission factors have been determined for all of them and are consistent with most recent published equivalent data. When possible, light-duty and heavy-duty duty traffic emission factors are also determined. Most of the first ones are in good agreement with emissions from chassis dynamometer measurements in absence of significant non-combustion emissions. This study has shown that ratios involving copper (mainly Cu/Fe and Cu/Sn) could be used to trace brake-wear emissions as they seem to be roughly constant in Europe and as longer as Cu-free brake are not largely spread. In France where the traffic was largely dominated by diesel vehicles in 2011 (70 %), the OC/EC ratio typical of traffic emissions was around 0.44. On the contrary, the use of quantitative data for source apportionment studies is not straightforward for the identified organic molecular markers; while, their presence seems to well-characterized fresh traffic emissions.</p>