عنوان مقاله [English]
Impacts of traffic conditions on exhaust emissions and the fuel consumption of passenger cars in Arak city have been investigated in this paper. For this purpose, several measurements in various routes of Arak city at different time intervals using GPS system were investigated. 212245 raw samples have been gathered and classified as 2340 separate micro trips. The micro trips were then clustered as three separate clusters using the fuzzy clustering approach. Centers of fuzzy clusters were then selected as the representative traffic conditions, i.e. congested, urban, and extra-urban. Finally, based on representative traffic conditions, the driving cycle for Arak city was developed. Exhaust emissions as well as the fuel consumption of three common vehicles in Arak city including Samand with national engine with gasoline fuel, Samand with the national engine with CNG fuel, and Pride were estimated at various traffic conditions using a backward-facing simulation approach. Simulation results revealed that conventional ECE-EUDC and TEH-CAR driving cycles could not give a good estimation of the fuel consumption and exhaust emissions in Arak city. Moreover, traffic conditions had a considerable impact on exhaust emissions and the fuel consumption in Arak city, as a drastic increase in the fuel consumption was reported while vehicles were experiencing congested traffic conditions. At the same time, despite prior expectations, due to specific nature of the congested traffic condition in Arak city, not only HC and but also CO and NOx emissions were increased.