During the day, when drivers enter a tunnel from a brightly lit exterior, the outside brightness is much higher than the inside. This prevents their eyes from adapting instantly, and the tunnel entrance appears to be a dark "hole," making it impossible to discern details such as obstacles and slow-moving vehicles. This presents the most critical and dangerous issue at the entrance.

In order to combat the "black hole effect", extremely high lighting brightness must be set at the entrance section, which means that a large number of high-power lamps need to be installed, resulting in extremely high energy consumption and huge operating costs.

The brightness of natural light outside the tunnel varies with time, weather, and season. Furthermore, higher vehicle speeds require a smoother transition in brightness, placing higher demands on the brightness design of the entrance lighting. Glare also needs to be controlled to avoid creating new safety hazards.

Low-quality or traditional lamps experience severe light decay, with brightness dropping significantly after a period of use. Color temperature drift leads to inconsistent light colors along the road, impacting visual comfort and safety. Irrational light distribution angles also result in low tunnel lighting uniformity.

Incompatibility between equipment and protocols across different brands and generations makes retrofitting existing tunnel lights difficult. Furthermore, intelligent lighting is expensive, requiring a high initial investment. Furthermore, there's the challenge of interoperability between the lighting system and other systems, such as transportation and security.

The human eye needs an adaptation period when going from bright to dark. The transition section is the transition from the entrance section. This physiological lag process is the main cause of safety accidents.

If the brightness change in the transition section is not continuous and gradual, but there are obvious steps or jumps, it will force the driver to adjust his vision frequently, increasing visual fatigue and insecurity.

To ensure uniform road brightness, lamps must be spaced and arranged in a certain pattern. However, if the lighting distribution is poorly designed or the lamps are installed at an inappropriate angle, they can easily shine directly into the driver's eyes, causing disabling glare or discomfort glare, which in turn reduces visibility.

The central section has a large number of lamps that need to run 24/7, making them a huge energy hog in the tunnel. If traditional high-pressure sodium lamps or inefficient LED lamps were used, the electricity costs would be staggering.

Monotonous lighting environments and enclosed spaces can easily cause drivers to experience visual fatigue, decreased concentration, and prolonged reaction time, which is particularly evident in long tunnels.

The large number of lamps increases maintenance time and the incidence of failures. Traditionally, faulty lamps are difficult to detect in a timely manner or even impossible to detect. Maintenance requires partial road closures, increasing operational risks.

This is the core and most dangerous pain point at the exit. The moment a driver exits the tunnel, the exit is like an extremely bright "white hole." The intense glare causes the driver's vision to go blank, temporarily impairing their visual function.

In rare cases, if the brightness of the exit section is too high and the connection with the external brightness is unnatural, when the driver passes through quickly, due to visual persistence, he may feel that the tunnel portal is like a black frame after exiting. This is called the "black frame effect". Although it is not common, it can also interfere with vision.

High-brightness lighting designed for the exit section during the day can be too bright at night, dawn, or dusk. This results in a significant amount of power consumption when it is not needed. Furthermore, the tunnel is dark, and the overly bright exit section itself becomes a "white hole," which can also cause discomfort and glare for drivers.