This study was designed to undertake extensive measurements, were designed to evaluate the effectiveness of street sweeping and washing (S/W) for controlling ambient PM. The objective of this study was to evaluate dynamic PM10 variability and an effective S/W (ηT、ηp、ηd、ηs) method for controlling air quality in Taiwan. It applied a modified regenerative vacuum sweeper (RVAS) and efficient washer to evaluate the effectiveness of S/W. Effects of traffic volume and wind velocity on the S/W efficiencies are also discussed in the paper. In this study, the sweeper and washer were traveling in one lane and U-turned into the lane in the opposite traveling direction. Each lane was swept and washed only one time in each test. The travel distance for the sweeper and washer was kept to about 0.5km. Dynamic PM10 variability was measured to evaluate of the S/W effectiveness. It was found that the direct impact of sweeping on ambient PM10 concentration was shortly lived, lasting no more about 1-2 hours. Effectiveness of S/W for controlling ambient PM was evaluated by TSP/PM10 measurements and determining silt load from active traffic streets. It did good job collecting the visible fine particles on roads, the method of S/W tested was effective at removing the sources of the road dust particles. The S/W efficiencies were obtained based on the experimental data of silt loading, TSP and PM10, and the relationship of the two efficiencies also can be expressed. But it is still necessary to clarify some constraints to apply the results obtained from the work, like a need of more information to verify the results for other conditions.