LED tunnel lights have become a new type of lighting fixture developed in recent years due to their outstanding advantages such as long life, low energy consumption, high luminous efficiency, and controllable illumination angle, and are commonly used in road tunnel lighting. Due to the particularity of tunnel lighting, the arrangement of LED tunnel lights used is also different from conventional lighting fixtures.

1. Why are the LED tunnel lights at the entrance and exit of the tunnel denser?
This is determined by the special structure of the tunnel and the physiological structure of the human eye. Since the tunnel is a semi-closed structure, the brightness difference between inside and outside the tunnel is large. When the vehicle enters or exits the tunnel, the human eye needs to adapt to the time, that is, the "adaptation lag" occurs. When a vehicle drives into the tunnel during the day, due to the sudden drop in brightness, the human visual response lags behind to form a "black hole effect", which makes it difficult to identify the situation in the tunnel; and when the vehicle exits the tunnel, a "white hole effect" is formed, causing strong glare.

In order to avoid the large difference in light intensity inside and outside the tunnel and short-term visual disturbances to the human eye, it is required that the LED lights at the entrance and exit of the tunnel should be denser, so as to reduce the light intensity difference between the outside and inside of the tunnel during the day and ensure the driving safety of drivers.

2. Why are the LED tunnel lamps in the tunnel arranged in two columns?
The LED lamps in normal tunnels are often designed in two rows, which is also for the consideration of the driver's driving safety. Generally speaking, the LED tunnel lights are divided into two rows and two lights, which are located on both sides, and the top lights are opposite to the ground, so that they can illuminate the space without reflection. As shown in the figure below, it is a comparison of the lighting effects of single-row ordinary lighting fixtures and double-row LED tunnel lamps.