The first objective was to determine the emission load from vehicular exhaust gases. This partial objective was based primarily on the surveys of the Cologne emission register performed in the state of North Rhine - Westfalia. As a second objective, immission measurements were performed in selected streets of the city of Cologne. By using a computer analysis, the relation between vehicular emissions and the resulting immissions was determined, taking the various wind conditions into consideration. In the second part of the study, the costs of reducing the emissions of vehicles were determined by means of an inquiry in the automobile industry.