This paper presents a study of the effects of different traffic flows on the basic pollutant emissions at a signal-controlled intersection and a roundabout in the urban area of Thessaloniki, Greece. Detailed traffic volume measurements were made, and information was collected on traffic speed and other parameters, during both peak and off-peak periods. Analyses were made of the effects of various traffic flows on concentrations of: (1) carbon monoxide (CO); (2) hydrocarbons (HC); and (3) nitrogen oxides (NOx). The parameters of formulae for pollutant emissions were estimated, using models provided by the SIDRA (Signalised Intersections Design and Research Aid) computer program. The input data were data were various traffic flows with existing geometric and timing characteristics. Various estimations and predictions of pollutant emissions were obtained from SIDRA computer runs. Comparisons were made between pollutant emissions resulting from traffic flows at the two types of intersection. For example, for higher traffic volumes, the HC emissions at the signalised intersection were about twice as much as those at the roundabout. Relationships between estimated and measured pollutant concentrations were also analysed.
Samenvatting