UkrainianProfessional Education

Abstract

The study presents the results of the research of the impact of traffic intensity and traffic flow composition on the capacity of highways and bridge crossings based on mathematical and numerical modeling methods. The main factors affecting the capacity of highways and bridge crossings have been identified. The methodology for determining the level of traffic and capacity of highways approved by the State Service of Highways (now the Restoration Agency) was adopted as the main calculation basis for numerical modeling. Also, for calculations, updated statistical data, given in open literary sources, were used. 11 test options with different composition of the traffic flow were considered: from 0% to 100% of the share of passenger cars in the composition of the traffic flow. The average speed of the traffic flow was determined depending on the geometric parameters of the road - the radii of the horizontal curves in the plan and the longitudinal slope of the carriageway. It is shown that the average speed of the traffic flow increases with an increase in the value of the radius of the horizontal curve and with a decrease in the value of the longitudinal slope of the carriageway of the road, which is due to the improvement of traffic safety conditions and the possibility of moving vehicles at higher speeds. Also, the results of the numerical modeling showed an increase in the average speed of the traffic flow with an improvement in the level of coverage of the road (bridge crossing). It is shown that an increase in the share of cars in the traffic flow leads to an increase in the average speed of the entire traffic flow, which is explained by their more "compact" dimensions, compared to trucks, buses and road trains. The smallest practical carrying capacity of a highway or bridge crossing corresponds to a column of cars at the speed of free movement. The highest practical throughput corresponds to the traffic intensity at the minimum interval (optimal speed). Also, with an increase in the traffic flow of trucks and largesized vehicles, the capacity of the road decreases. This determines the relevance of research in the direction of developing load models based on the actual parameters of heavy-duty rolling stock when determining the loadcarrying capacity of highways and overpasses

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