Under the system, the brightness of street lighting is controlled automatically by the presence or absence of people on that part of the street through the sensor attached to the lighting pole.

The SMG saw a power usage reduction of 30% through the operation of the system on Mugyo-ro, Sejong-ro, and Namdaemun-ro 10-gil during a test run which began in 2014.

Under the system, the brightness of street lighting for roads becomes brighter up to a distance of 100 meters in consideration of the speed of passing vehicles, and then becomes darker with the passing of the vehicles. As for street lighting for sidewalks, their brightness becomes brighter so as not to cause inconvenience to pedestrians. A new area where the system is to be installed is Jangan Beotkkot-ro, Dongdaemun-gu. Local residents there have expressed their desire to have street lighting in back alleys of their neighborhood turned off when there are no passersby, as the lights disturb their private life.

The SMG plans to install the system on a total of 260 street lighting poles on the 3.4 km section by the end of November this year, and expects that power usage will be reduced by 30% to 50% in those areas. In 2015, the power usage by street lighting in Seoul came to 145GWh, which was translated to 22.6 billion won in power rates.

The SMG also expects that the wider use of the system will go a long way in settling light pollution problems. According to the June 2016 issue of Science Advances, an international journal, South Korea (89.4%) ranked the world’s highest in terms of light pollution, second only to Italy (90.3%). The SMG plans to gradually expand the system to other areas.