## 2 Literature Review
In simulation environments, direct measurement of illumination is not possible, as the light sources are merely projected images of lamps on a screen [14]. For instance, in the Zigiana Tunnel, real-world measurements of road surface luminance ranged from 4-10 cd/m\({}^{2}\), while overall illumination levels were between 50 and 2000 lux. When images of the tunnel were projected onto the simulator screen of the study, the corresponding road surface luminance values ranged from 1.5-3 cd/m\({}^{2}\). By capturing photographs and measuring luminance levels in actual tunnels, simulator projectors were calibrated to achieve relative validity, ensuring the simulated lighting conditions closely resemble real-world scenarios. Numerous studies have utilized vehicle simulators to explore tunnel safety and operations [36; 37; 38]. For example, [PERSON] [39] investigated the use of driving simulators to evaluate the effectiveness of road geometric designs. They concluded that simulators are valuable tools for analysing driver speed and steering responses, making them effective in assessing the safety and functionality of road designs. This finding reinforces the importance of simulators in tunnel safety and operational research. [PERSON] et al. [40] conducted a simulator study to assess the speed and lateral positioning of light and heavy vehicles in tunnels. The study found that simulators offer realistic results for tunnel-related research. Additionally, [PERSON] et al. [36] used a driving simulator to examine how different lighting conditions impact driver behaviour in road tunnels. They found that gradual transitions between light and dark environments reduced driver discomfort and improved performance, underscoring the importance of lighting design in tunnels. [PERSON] et al. [38] used a simulator to observe driver responses during a simulated fire scenario. Their findings showed that drivers' evacuation decisions were influenced by factors such as tunnel length, visibility, and the proximity of emergency exits. This research contributed to improving tunnel evacuation protocols and emergency signage. In another study, [PERSON] et al. [37] simulated a two-lane tunnel under varying traffic densities to analyze driver behaviour. The study revealed that narrow lanes and high traffic density increased driver stress, leading to more frequent lane deviations. In conclusion, a review of the existing literature reveals that no study has focused on informing drivers about stalled or malfunctioning vehicles in tunnels before they encounter them, nor has any research explored the resulting lane use and lane-changing behaviour (LCB) in a simulator environment. While previous studies have examined various aspects such as driver behaviour, safety, driver training, lighting, fire response, and lane discipline in tunnels using vehicle simulators, this study aims to make a significant contribution to tunnel safety. It will do so by investigating drivers' LCB in different scenarios. The proposed scenarios in this study will seek to develop safety measures that inform and guide drivers when stalled or malfunctioning vehicles are present in tunnels.