## 6 Conclusions  
The FFS of vehicles on sections of the city road network is an important indicator that is widely used in traffic management tasks. Since the driver's choice of driving speed in conditions of low road traffic is influenced by many factors of not only a technical but also a psychophysiological and social nature, the issue of studying FFS distributions on road sections for different cities and regions of the world is relevant. Reliable results can be obtained by field observations of the movement of cars in real conditions. Such experimental studies were conducted for four sections of the road network of the city of Kharkiv (Ukraine), where a portable radar was used to record the speed of cars. The processing of the received data made it possible to obtain certain practical results. It was found that a large number of drivers were exceeding the established speed limits, especially on sections of main streets. The functional class of the street was found to be an important factor affecting the value of FFS. The average values of FFS on sections of main streets, compared to streets of local connections, turned out to be 19 km/h higher on average, which indicates a higher speed regime. At the same time, one-way traffic has less influence on the FFS distribution, especially for arterial streets. No unequivocal influence on the shape of the FFS distribution of the functional class of the street and one-way traffic was found. A non-trivial result turned out to be a smaller value of the average speed for a street of local flow with one-way traffic, which can indicate both the ambiguity or low significance of this factor or the presence of other factors that influenced the choice of speed by drivers. Both the functional class of the street and the one-way traffic factor did not significantly affect the shape of the FFS distribution curves, although the distributions for arterial streets had more pronounced peaks. The slight difference in the characteristics of the FFS distribution for sections of roads with one-way and two-way traffic indicates a low correlation of this factor. This means, in particular, that when modeling traffic on streets of the same functional class, it is possible to use identical FFS values for both one-way and two-way traffic, whereas to simulate traffic on streets of different functional classes, different values of the FFS parameter should be used. When choosing the optimal number of intervals according to [PERSON]'s formula, experimental distributions of FFS were approximated with sufficient accuracy by the following distribution laws: Normal, Gamma, Log-normal, and Chi-square. At the same time, for a main street with one-way traffic, due to the presence of a more pronounced peak and a relatively greater asymmetry of the distribution, the Log-normal distribution showed greater accuracy. For a main street with two-way traffic, the Normal and Chi-square distributions showed better accuracy. For the local streets, due to the relatively greater uniformity of the distributions, the Chi-square distribution showed better accuracy. The obtained results can be useful for solving the problems of modeling and forecasting the parameters of traffic flows on the streets and road networks of large cities, as well as the preliminary results when conducting further scientific research on this problem. Further studies may include analyzing factors such as road geometries, intersections, and pedestrian circulation separately for each type of street such as city thoroughflares, local thoroughflares, and intra-district streets. Summarizing the results of this and similar studies could result in the development of a reference manual or regulatory document that provides FFS values for all types of urban streets. Such a document would be very useful for creating models of the functioning of the street network of cities both in Ukraine and other Eastern European countries with similar topologies of the street and road network. Conceptualization, O.R. ; methodology, O.R. ; software, V.B. ; validation, G.S.