街灯は、道路や歩道に人がいないときでも、一晩中最大の明るさで点灯していることがよくあります。

READING

Streetlights are often kept on at full brightness throughout the night, even when roads and paths are empty. Some local governments are installing motion sensors on lights to change this pattern. The lamps remain dim when no movement is detected and become brighter when a pedestrian, bicycle, or vehicle approaches. After the person or vehicle passes, the lights return to a lower level.

Supporters believe these systems are beneficial. Dimming lights when streets are unused can reduce the electricity needed for public lighting. This can lower operating expenses and reduce emissions when the electricity comes from fossil fuels. Another benefit is that unnecessary brightness is reduced during quiet hours. Less light may enter nearby homes or disturb insects and other animals that depend on natural darkness for feeding, movement, and their normal daily cycles.

However, critics have concerns. Sensors may have blind spots or fail to work properly, causing them to miss approaching pedestrians. As a result, a streetlight may remain dim even when someone is nearby. This could create dangerous situations because pedestrians may have difficulty seeing obstacles or being noticed by drivers and cyclists in poorly lit areas.