Estimation of air pollutant emissions in flower roundabouts and in conventional roundabouts

The road pollutant emissions, above all in urban context, are correlated to many infrastructuralparameters and to traffi c intensity and typology. The research work on road junction geometry,carried out in European research centres, has recently allowed to design new road intersectiontypes which are of undoubted interest, especially in terms of traffi c functionality and safety, like thefl ower roundabouts (in which right-turn manoeuvres do not confl ict with the circulating fl ow). Themain objective of this paper is to propose a model for the estimation the capacity, delay, levels ofservice and the pollutant emissions into fl ower roundabouts. A comparative analysis between conventionalroundabout and fl ower roundabout has been carried out in terms of CO, CO2, CH4, NO,PM2,5 and PM10 vehicular emissions, evaluated by mean of COPERT Software which is developedas a European tool for the calculation of emissions from the road transport sector.