Traffic-related Environmental Impact Mapping In Downtown Amsterdam

Abstract

Traffic-related environmental impact mapping includes an inventory of all downtown city streets known to have a traffic density surpassing a maximum number of cars per day. The environmental components to be taken into account are carbon monoxide, nitrogen dioxide and benzene as air pollutants, on the one hand, and the noise nuisance level on the other. The impact mapping has been done by applying the CAR-model for the calculation of air pollutant concentrations and the Standard Calculus I-model for the calculation of the noise levels involved. Both models have been extensively validated and are mandatory under Dutch law. The models are able to forecast an average air pollutant and noise nuisance level which is valid for a street trajectory with an average length of 200 meters. Comparison of calculated values with standard values results in a map of street trajectories where ambient air quality and noise level standards will be exceeded. The results of the study in downtown Amsterdam demonstrate that the ambient air quality standards for both carbon monoxide and nitrogen dioxide were exceeded for a total street length of 27 and 49 kilometers, respectively in 1987. For noise, the total length of street trajectories not in compliance with the standard to be observed was 240 kilometers in that year. Starting from the position that no environmental quality standard may be exceeded, the models are able to calculate to what extent traffic flow density must be restricted in the future in the various street trajectories concerned. The environmental impact map thus obtained for the year 2000 may be designated as the Standard Alternative Traffic Flow Pattern Map. It is shown that the ambient air quality standard for carbon monoxide will not be exceeded in 2000 at all because of an improved automotive exhaust quality. Transactions on Ecology and the Environment vol 3, © 1994 WIT Press, www.witpress.com, ISSN 1743-3541 386 Computer Simulation In order to avoid any further standard violations for benzene and nitrogen dioxide, traffic flow should be curtailed by at most 50% over a total street length of 27 kilometers. For noise, a reduction in traffic flow of at most 75% has to be achieved over a total street length of nearly 180 kilometers. It can be concluded that noise nuisance is the critical factor in the design of traffic flow density limitations in downtown Amsterdam.