Throughout the international railway community, there are many different designs of elastic fastening systems that have been developed to meet a variety of design specifications and performance expectations. Historically, in North America, the most common types of fastening systems used for concrete crossties are the Safelok I or e-clip systems. In recent years railroads have begun implementing the Skl-style (W) fastening system with concrete crossties in existing and new heavy haul freight railroad mainlines. The magnitude of lateral force applied to the Skl-style fastening system is important information for both design and application purposes. Despite this importance, the lateral force applied to the Skl-style fastening system in a heavy haul freight railroad environment has never been quantified to date. To better understand how the Skl-style system performs under the magnitude of lateral loads observed on heavy haul freight railroads, research was conducted by the Rail Transportation and Engineering Center (RailTEC) at the University of Illinois at Urbana-Champaign (UIUC). The focus of this paper is on laboratory characterization of the lateral load path through the Skl-style fastening system using novel instrumentation techniques that are subjected to heavy haul freight railroad loading conditions. The investigation of fastening system performance included an evaluation of lateral load distribution through the track superstructure, and a single fastening system. Laboratory experimentation concluded that lateral wheel load is primarily distributed to three crossties, the relationship between lateral wheel load and lateral force resisted by field side angled guide plate is non-linear, and that the design of the Skl-style fastening system allows lateral force to be transferred into the crosstie below the worst case concrete compressive fatigue strength. The observations from this study will assist the rail industry in improving fastening system design and developing mechanistic track structure design method.