## 1 Introduction  
Horizontal curves on roadways have long been recognized as critical locations for traffic safety concerns, exhibiting significantly higher crash rates than straight road segments [1, 2]. This elevated risk is intricately linked to the complexities drivers face in accurately perceiving curve geometry, judging appropriate speeds, and maintaining proper vehicle control [3, 4]. Consequently, many severe and fatal crashes occur on horizontal curves, underscoring the persistent need for effective countermeasures to positively influence driver behavior and mitigate these risks [5]. Understanding the factors that shape driver perception and developing interventions that leverage these perceptual mechanisms are crucial for advancing road safety on curved alignments [6]. A diverse range of road safety interventions has been explored and implemented in response to the safety challenges presented by horizontal curves. These include geometric design modifications, improved warning signs, advisory speed limits, and pavement treatments [7,8]. Among these strategies, perceptual countermeasures, especially road markings, have gained considerable attention for their ability to directly impact driver behavior by offering prominent visual cues about the road ahead [9]. Road markings, including centerlines, edge lines, lane markings, and curve-specific treatments such as chevrons and rumble strips, are essential for delineating the roadway, indicating alignment changes, and encouraging drivers to adopt safer driving practices, like lowering speed and adjusting their lateral position [5,10]. Using driving simulators has significantly advanced the investigation of driver behavior in response to different road design elements [11, 12, 13]. These advanced tools provide a safe and controlled environment for researchers to examine how drivers engage with virtual road scenarios and react to alterations in the road environment, including changes in geometry and pavement markings [14]. Driving simulators enable precise measurement of critical driving parameters, including speed, lateral position, acceleration, and braking behavior [15]. This technology offers valuable insights into the effectiveness of various safety interventions without putting participants at risk of real-world hazards [16]. Numerous studies have used driving simulators to assess the impact of different road marking strategies on driver behavior in horizontal curves, investigating how centerline treatments, edge line enhancements, chevron designs, and speed reduction markings affect driver performance [8,10,17]. The current state of research on road markings in horizontal curves reveals a diverse range of findings. While many studies indicate that specific road marking treatments can result in positive changes in driver behavior, such as reduced speeds and improved lane keeping [18], other studies have yielded less conclusive or even contradictory results [10]. For instance, [PERSON] et al. [19] found that applying road markings can lead to increased speeds, potentially due to drivers perceiving a safer environment. This highlights the complexity of the interaction between road markings, driver perception, and behavior, and underscores the need for further research to understand the nuanced effects of different marking types and configurations [20,21]. Research in this field includes studies analyzing the effects of wider edge lines, centerline rumble strips [22,23], chevron designs [18,24], speed reduction markings [9,25], and, more recently, self-luminous road markings [26] on driver behavior, experimentally tested using driving simulators [27]. However, a comprehensive understanding of the combined effects of specific median and edge line perceptual treatments remains limited. This paper employs a driving simulation to investigate innovative perceptual road marking countermeasures for horizontal curves.