When the cars pass through the tunnel portal, the human pupils will change due to the brightness of the light. When entering the tunnel, the light suddenly becomes darker, the eyes suddenly cannot adapt, and the driver will feel pitch black; when exiting the tunnel, the light suddenly becomes stronger, the pupils shrink quickly, and the driver will feel white. This phenomenon is called the tunnel "black hole" and "white hole" effect. The phenomenon will last for 3 seconds which is very dangerous on the highway.
Fonda’s RS485 solution solved the “black hole” and “white hole” problem with customized light dimming for different parts of the tunnel. Besides, the automatic lighting control system of the tunnel lighting reduced power consumption up to 43% after reconstruction.
