## 1 Introduction  
Tunnel-interchange connection sections, increasingly prevalent due to geographical constraints, present significant challenges to driving safety and stability. These sections, characterized by their small spacing and rapid environmental changes, often lead to complex traffic flow patterns and frequent vehicle interweaving. This unique environment critically affects two key driving behaviors: car-following (CF) and lane-changing (LC) [1]. Influenced by road infrastructure, the driving environment, and driver characteristics, these behaviors govern vehicles' longitudinal and lateral movements, thereby impacting traffic flow efficiency and safety [2, 3, 4]. Drivers traveling on these connection sections must swiftly adapt to shifts in environmental scenarios and detect LC opportunities within limited time frames [5, 6], which may alter drivers' decision-making processes and driving responses [7, 8]. In addition, the difficulty of setting directions also increases the difficulty of visual recognition in the area [9, 10]. Nevertheless, due to the multitude of involved variables and the complexity of conducting empirical experiments, the driving behavior characteristics on these sections remain largely unconfirmed. Understanding the combined effects of tunnel and interchange divergences on driving behavior is therefore crucial. While numerous studies have investigated driving characteristics in either scenario, their cumulative impact remains less explored. In tunnel sections, the drastic change in illuminance is a key factor affecting drivers' perception of distance and speed [11; 12; 13]. Empirical data indicate that drivers respond more effectively when the lighting contrast between the inside and outside of the tunnel is minimal and the tunnel length is short. Otherwise, it may lead to increased speed fluctuations and affect the reaction time [14]. Other factors such as visibility distance, visual bias, and tunnel length may also alter drivers' perception, decision-making, and speed fluctuations [15; 16; 17; 18]. Drivers aiming to exit the main line have to shift from the inner lane to the outer lane, resulting in frequent and concentrated forced diverging behaviors. This purposeful LC process is so-called mandatory lane changing (MLC) [19; 20]. Multifarious factors influence MLC behavior in divergent areas. For example, research by [PERSON], et al. [21] indicates that increased traffic density and a higher probability of braking substantially decrease the LC durations and accepted gap of drivers. [PERSON] and [PERSON] [22] posit that the closer a vehicle is to the end of the auxiliary lane, the more likely the driver is to diverge. Moreover, factors like roadway design [23; 24], traffic control facilities [25], traffic flow [26], and interaction with surrounding vehicles [27] significantly dictate driving characteristics in divergence areas. Additionally, drivers in diverging areas tend to focus their visual attention on obtaining directional information, often at the expense of monitoring traffic conditions ahead. This shift in focus is a notable contributor to traffic accidents [28]. In situations with an abundance of directional signs, the overload of information can increase drivers' cognitive load, possibly leading to errors [29]. An excessive amount of signage has been associated with driver distraction, lane deviations, and speed variations [30]. While well-designed traffic facilities can improve drivers' perception abilities, the placement of signs in connection sections is distinctly different from typical roadways due to the spatial constraints in tunnels [31]. Hence, the impact of connection section sign information on driving behavior warrants further exploration. Previous research has made notable progress in exploring how visual contrasts, sign information, and divergent environments affect driver behavior. However, the added psychological strain faced by drivers near tunnel and interchange exits could impair their ability to process information and make decisions [6; 13].