URBAN MOBILITY ECONOMICS: MODELING THE ECONOMIC EFFICIENCY OF TRAM TRANSPORT CONSIDERING INFRASTRUCTURE, TIME, AND INTEGRATION

Abstract

The article examines the economic efficiency of tramway systems within the framework of urban mobility economics, taking into account infrastructure conditions, transport demand, travel time, pricing policy, and the level of system integration. The relevance of the study is driven by increasing operating costs, the deterioration of track infrastructure, and the limited financial capacity of municipalities, which constrain both tariff adjustments and large-scale investments. The paper develops an economic and mathematical model that formalizes the relationship between infrastructure quality, operational speed, travel time, generalized travel cost, and passenger demand. It is demonstrated that infrastructure acts as a system-forming factor, influencing economic performance indirectly through its impact on travel time and perceived service quality. The concept of generalized travel cost is used as a key integrative indicator that captures not only monetary expenses but also time-related and behavioral components of passenger choice. The model incorporates a nonlinear demand response and introduces a socially acceptable fare constraint, reflecting the dual economic and social nature of public transport systems. It is shown that while improvements in infrastructure initially lead to significant increases in both demand and revenue, the effect becomes limited once the fare reaches its socially acceptable upper bound. This results in diminishing marginal returns on investment and highlights the existence of a threshold level of infrastructure quality below which tram operations become economically inefficient. Special attention is given to the role of transport system integration, which is modeled as a multiplier of effective demand. The results indicate that integration – through coordinated routes, seamless transfers, and unified ticketing – can significantly increase ridership without substantial capital investment, making it a critical policy instrument under financial constraints. The findings suggest that the economic performance of tram systems cannot be explained by isolated parameters but is determined by the complex interaction of infrastructure, pricing, time costs, and behavioral responses. The proposed model provides a conceptual and analytical basis for evaluating investment decisions, optimizing operational strategies, and designing sustainable urban transport policies.