Title: Validation of emission factors for road vehicles based on street tunnel measurements

Authors: Peter J. Sturm, Johannes Rodler, Bernhard Lechner, Raimund A. Almbauer

Addresses: Graz University of Technology, Institute for Internal Combustion Engines and Thermodynamics, A-8010 Graz, Inffeldgasse 25, Austria. Graz University of Technology, Institute for Internal Combustion Engines and Thermodynamics, A-8010 Graz, Inffeldgasse 25, Austria. Graz University of Technology, Institute for Internal Combustion Engines and Thermodynamics, A-8010 Graz, Inffeldgasse 25, Austria. Graz University of Technology, Institute for Internal Combustion Engines and Thermodynamics, A-8010 Graz, Inffeldgasse 25, Austria

Abstract: The emission behaviour of road vehicles is regularly estimated by the use of emission factors and models. But there is only limited information available about the validity of such factors or models in real world situations. This is because validation requires roadside measurements and these add an additional element of uncertainty in the form of pollutant dispersion behaviour. Tunnel measurements can help to overcome this problem. Road tunnels can be used as big laboratories because the boundary conditions within such tunnels are well known. Such measurements were undertaken in a 10 km long road tunnel in Austria for a period of six weeks during autumn 1998 and another four weeks during spring 1999. An analysis of the data showed that CO emissions derived from the measurements were in good agreement with the emission factors; surprisingly, this was not the case for NO_x, especially for NO_x emissions from heavy duty vehicles. Due to the fact that the HDV share of the traffic was up to 35% of total traffic volume the effects of unbalanced emission factors were considerable. Differences of up to a factor of 1.6 between measured and calculated emission factors were recorded.

Keywords: emissions from road vehicles; real-world emissions; tunnel study; validation of emission factors.

DOI: 10.1504/IJVD.2001.001952

International Journal of Vehicle Design, 2001 Vol.27 No.1/2/3/4, pp.65-75

Published online: 15 Aug 2003 *

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