Particulate emissions from on-road vehicles in the Kaisermühlen-tunnel (Vienna, Austria)

Vehicular particulate emission rates for particle mass (PM), total carbon (TC), black carbon (BC), various trace metals (Zn, Cu, Pb, Ni, V) and elutable ions (SO42−, NH4+) were determined in a highway tunnel study performed 2002 in Vienna, Austria. For a typical workday fleet with a contribution of 14.8% heavy duty vehicles (HDV) and free cruising conditions averaged emission rates of 45.3±17.5, 39.7±7.3, 27.9±4.0 mg vehicle−1 km−1 were found for PM, TC and BC. Under weekend conditions with 8.1% HDV in the car fleet significantly lower emission rates were observed for TC and BC (35.9±11.9 resp. 24.6±6.9 mg vehicle−1 km−1), whereas the emission rate for PM was nearly unchanged (46.3±17.2 mg vehicle−1 km−1). As the HDV contribution in the car fleet and the emission factors of TC and BC were highly correlated, separate emission factors for HDV and light duty vehicles (LDV) could be derived. The HDV emission rates obtained for TC and BC were 129±36 and 99±34 mg vehicle−1 km−1, the corresponding rates for LDV were 24.3±7.9 and 15.6±7.3 mg vehicle−1 km−1. Totally averaged fleet emission rates for NH4+ and SO42− were 1.16±0.41 and 2.13±0.81 mg vehicle−1 km−1. The emission rates for trace metals Zn Cu, Pb, Ni and V were found to be in the range of 1–35 μg vehicle−1 km−1. A good correlation was observed between the individual trace elements except for Ni, indicating a similar dependency on traffic flow and driving patterns.