BRAESS'S PARADOX IN THE OPERATIONS OF JSC 'UKRZALIZNYTSIA'

Abstract

Introduction. In 2025, the functioning of Ukraine's railway network is characterized by adaptation to shifting logistical routes and the restoration of critical infrastructure. While transport system efficiency is traditionally linked to network expansion, in complex topologies, the emergence of shorter routes can create prerequisites for network anomalies. This article analyzes the dynamics of agricultural cargo transportation toward the ports of Greater Odesa following the restoration of traffic via the bridge at Voznesensk station. A pronounced concentration of freight flows at Chornomorska station is observed, creating the theoretical conditions for the Braess Paradox—a situation where individual cost optimization by market participants leads to an overall degradation of throughput capacity.

Purpose. To provide a scientific substantiation of the signs and prerequisites for the emergence of the Braess Paradox within the structure of railway transportation to the ports of the Odesa region in 2025, and to analyze the limiting factors that complicate the unambiguous identification of this phenomenon.

Materials and Methods. The research is based on the theory of transport flows and network equilibrium (the works of A. Pigou, F. Knight, and D. Braess). Statistical reports from JSC "Ukrzaliznytsia" for 2024–2025 and an analysis of the regulatory framework for tariff formation were utilized. Systems analysis methods were applied to evaluate the correlation between changes in tariff distance and the redistribution of market shares among port stations. The research methodology is based on conducting a correlational analysis between the alteration of tariff zones and the dynamics of port station market shares, alongside the application of systems analysis to isolate the impact of security factors on network throughput capacity.

Results. It is demonstrated that the introduction of the "short path" to Chornomorska station in 2025 created a significant economic gap (100–150 UAH/t) and a time advantage, which stimulated market reorientation: the share of the "Pivdennyi" port in grain exports reached 51.2%, while volumes at the Odesa-Port station decreased by 23%. However, the authors note that an unequivocal claim regarding the occurrence of the Braess Paradox in its classical sense remains debatable. This is due to the inability to fully decouple the effect of "selfish routing" from the influence of systemic factors: systematic strikes on railway infrastructure that artificially limit throughput, and the general decline in transport volumes for other cargo types, which alters the operational model of the railway. Thus, the Braess Paradox is considered a probable scenario of network degradation, signs of which are already visible through excessive cargo concentration and delays in the coordination of loading plans.

Perspectives. A comprehensive set of measures for tariff harmonization within the Odesa hub is proposed to preventatively mitigate logistical imbalances. Further research should be directed toward developing a dynamic flow distribution model that accounts for the risks of physical infrastructure damage and the variability of the freight base structure, thereby ensuring the stability of the export sector under conditions of uncertainty.