To analyze the situation of city's pollution quantitatively and achieve the pollution-control strategy,four different graded roads in Changchun were investigated to get drive cycles of them on the basis of tested data.On the basis of analyzing the drive cycles of urban graded roads,the impact of vehicle emission factors and driving speed on three pollutants in the drive cycles of urban graded roads was studied.It is indicated that the speed of vehicle trends to be lower with the decreased grades of road,and...