Development of railway transportation and its effects on economic growth in Türkiye

In the global economic system, the quality of transportation infrastructure is among the most fundamental factors determining countries' pace of development and international competitiveness. The purpose of this study is to analyze the critical role undertaken by railway freight transportation (RFT) in line with Türkiye's sustainable growth objectives using an empirical approach based on data for the period 1977–2024. Railway transportation constitutes an indispensable component of modern logistics management due to its low unit cost advantage, high operational safety, and contribution to ecological sustainability. The comprehensive modernization initiatives and strategic railway projects implemented within Türkiye's transportation network reduce logistics costs in production processes, strengthen the global competitiveness of domestic producers, and directly expand trade volume. From a macroeconomic perspective, shifting a road-oriented transportation structure toward railways contributes to the improvement of the current account balance by reducing dependence on imported fuel, supports the fulfillment of environmental commitments by lowering carbon emissions, and decreases social costs by easing traffic congestion on highways. Moreover, connecting the inner regions of Anatolia to ports and major markets through railway networks acts as a catalyst for reducing regional development disparities and increasing local employment opportunities. This study consists of three sections. The first section addresses the relationship between transportation infrastructure and economic growth within a conceptual and theoretical framework and discusses the role of railway transportation within the economic structure. The second section examines the effects of railway transportation on economic growth in Türkiye, evaluating the sector's development, current structure, and its relationship with growth indicators within a theoretical framework. In the third section, which constitutes the empirical part of the study, the dataset is introduced, ARDL and nonlinear NARDL approaches are employed as analytical methods, and the obtained findings are interpreted. Through the applied econometric methods, the dynamic structure of short- and long-run interactions between railway freight transportation and economic growth is analyzed, and the possible asymmetric effects of positive and negative changes in transportation on growth are separately examined. Overall, the study aims to contribute analytically to the discussion of the role of transportation infrastructure in Türkiye in terms of economic performance, logistics efficiency, and regional integration. Keywords: Railway Freight Transportation, Economic Growth (GDP), ARDL Analysis, NARDL (Asymmetric Analysis), Transportation Infrastructure, Turkish Economy.