## 1 Introduction  
The construction of roads in mountainous regions is often complicated by steep and uneven terrain. To minimize excavation and earthworks, cantilever structures have gained widespread adoption as a key solution for roadbed support [1, 2]. Conventionally, such structures are built using cast-in-place techniques, necessitating extensive on-site concrete pouring and curing. These processes not only demand substantial labor but also prolong construction schedules [3, 4]. In response to these challenges, prefabricated cantilever structures (PCSs) have been developed as an efficient and practical alternative. PCSs are highly adaptable to rugged mountainous landscapes and have become the preferred structural solution for mountain road construction [5, 6, 7]. As illustrated in Figure 1, these systems are composed of multiple prefabricated elements, including inner and outer longitudinal beams, cantilever beams, anchor rods, columns, retaining plates, and their corresponding foundations. Unlike conventional cast-in-place methods, these prefabricated components are produced in a controlled factory environment, ensuring consistent quality and precision. Once transported to the construction site, they are rapidly assembled, significantly improving construction speed while minimizing on-site labor requirements [8]. The assembly process also enhances overall safety, particularly in hazardous construction settings [9]. In contrast to conventional roadbeds, such as those formed by cutting slopes or filling embankments, prefabricated cantilever roadbeds are less influenced by topographical variations, leading to smoother roadway alignments and minimized elevation discrepancies, thereby demonstrating superior adaptability [10, 11, 12, 13]. Several studies have explored the structural performance of PCSs [14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24]. Given that the beam-column connection plays a crucial role in the stability of these systems, research on their seismic behavior has shown that while various connection techniques have negligible effects on the longitudinal seismic response and risk distribution of primary structural elements, they substantially influence the transverse seismic behavior and associated risk patterns [14]. Regarding connection strategies for PCSs, [PERSON] et al. [15] conducted both scaled physical tests and finite element (FE) simulations to examine the mechanical properties of bolted joints, demonstrating their effectiveness in preserving structural stability. Moreover, factors such as cantilever beam width and internal reinforcement grid configurations have a notable impact on the beams' ultimate load-bearing capacity [16; 17; 18]. Different cantilever beam types also exhibit varying responses under extreme loading conditions [19; 20]. Collectively, these findings offer essential insights for optimizing the design of prefabricated cantilever structures. Studies have shown that vehicle loads play a critical role in the fatigue deterioration and potential failure of cantilever structures. Consequently, accurately evaluating and predicting the influence of traffic load distribution is essential for ensuring the long-term structural performance of these systems [22; 23; 24; 25; 26]. At present, the impact of vehicular loads on cantilever structures is primarily examined through numerical simulations [27; 28; 29; 30; 31]. Large-scale vehicle load testing is vital for assessing structural integrity and has been employed to detect potential deficiencies arising from material imperfections, construction inconsistencies, or long-term operational wear [32; 33; 34]. [PERSON] et al. [32] analyzed the behavior of modular truss structures under varying vehicular loads, highlighting that different loading approaches significantly affect bridge performance.