## 1 Introduction  
Countries with a relatively short history of railway infrastructure development reference other international standards for design and maintenance of tracks. In the Middle East and South East Asian countries, the International Union of Railways (UIC) codes have been adopted as their own standards. For example, the Korean Railway Code (KRC), the representative design specification code for both ballast and concrete track structures is mostly drafted by adopting the Union of Railways (UIC) or the American Railway Engineering and Maintenance-of-Way Association (AREMA) code. It is common knowledge in the academic field of railway engineering that, due to the respective environmental conditions and the difference in the types of components used in the various countries, the evaluation criteria and the methods are different case by case, nor are they fully theoretically consolidated. [PERSON] et al., discuss an estimation method of static track modulus using elastic foundation models and outline the difference of the proposed method and the various existing methods for calculating track modulus [1]. [PERSON] et al., outline many of the significant dynamic factor calculation methods applied in the different nations and their respective evaluative metrics [2]. [PERSON] provides a review of the structural monitoring methods upon investigating the gauges and sensors used for field instrumentation [3]. [PERSON] discusses a new track support stiffness (TSS) evaluation method without relying on wheel load data, and instead calculating the TSS using rail displacement and train speed [4]. A paper by [PERSON] et al. is one of the few existing studies that attempts a similar purpose as this study, where current practices of track analysis of ballasted tracks are reviewed and compared [5]. The study discusses the theoretical limitations of some existing standards, and that there is a lack of a singular method for analyzing the track dynamic response currently practiced in the U.S., nations using the European Standard (CEN) codes, and Australia [6]. Review of existing studies clearly illustrates that there are different methods for calculating the respective parameters for dynamic stability evaluation of railway track structures, and each new method is developed and proposed to take into account an environmental or technical factor that was not previously taken into account [7]. One such issue that is not often discussed is the application of the same evaluation criteria for different track structures of different track moduli, such as is the case in Korea. This is particularly problematic considering the differences between concrete and ballast track structures, where the track support stiffness is considerably different between the two different structure types, but the evaluation criteria for satisfactory track stability performance requirement (safety limit) is the same [8]. Different nations account for different properties in their standard specifications and design codes, and numerous studies discuss inclusion of new factors in the calculation of track parameters. This serves as an indication that while detailed performance evaluations exist, they are not necessarily consolidated or they are not being employed where necessary, and detailed studies on this issue have not been conducted in the railway academic field [9]. While it is a given fact that the respective national standards and specifications cannot all take into account the differences in the track properties and incorporate them into the evaluation regime, an actual investigation and comparison of ballasted track structures and concrete track types should be conducted to confirm how much of the difference in their properties affect our understanding of their track performance [10]. In light of this issue, this paper conducts an experimental study by trackside measurement through field instrumentation of track structures with different components and modulus properties.