In this paper we have presented a methodology used to determine actual acceleration, velocity and traveled distance profiles of vehicles of different categories in urban environment, as dominant microscopic traffic flow parameters. The tests have been done on representative arterial road in the city of Skopje. Within a period of one month, we have been observing the traffic on the subject arterial road and have determined the average traffic flow during different day periods. The structure of the traffic flow has also been analyzed. In the experiment we have used a probe vehicle equipped with adequate measuring system to follow more than 130 vehicles of different categories on the observed arterial road, imitating i.e. reproducing their behavior as much as possible. The final goal to determine the domains of these microscopic traffic flow parameters in specific velocity intervals, regarding different vehicle categories was reached. These results have shown to be very useful as input parameters in the single lane urban traffic flow simulator that we have developed.