Emission factors from road traffic from a tunnel study (Gubrist tunnel, Switzerland). Part I: concept and first results

In the industrialized world a large part of the emission of the primary air pollutants (NOx, volatile organic compounds (VOC) and CO) originates from road traffic. Here we present the concept and first results of a tunnel study which took place from September 20th to September 26th, 1993 at the Gubrist tunnel (close to Zürich, Switzerland) in which the emission factors of a large number of individual VOCs, total hydrocarbons (t-HC), CO, NOx and SO2 are determined. The first tentative results of the emission factors of NOx, CO, t-HC and 26 individual hydrocarbons (alkanes and aromatics in the volatility range from n-heptane to n-decane) for the average of all vehicles and the light duty vehicles at an average speed of 90 km/h are given.