Turn it off! Large digital billboards in Seoul distract drivers at night

A taxi driver looks at a digital billboard in Mapo District, Seoul, Thursday. Korea Times photo by Shim Hyun-chul

Kim Kyung-ho, a 50-year-old taxi driver, is no stranger to long hours behind the wheel and rising fuel costs, but Seoul’s rapidly expanding outdoor digital billboards have added a new burden to his daily drives, particularly at night.

“When those giant billboards suddenly light up, it’s blinding,” Kim told The Korea Times. “I know where they are now, but they used to catch me off guard.”

Kim’s experience reflects how Korea’s push to transform some of its busiest districts into glittering, billboard-filled spaces modeled on New York’s Times Square is raising concerns about glare that can interfere with nighttime driving.

To create urban landmarks and promote the outdoor advertising industry, the government first eased regulations in the area around Coex in southern Seoul’s Gangnam District in 2016, declaring it a free-display zone.

In 2023, it gave similar designations to areas around Gwanghwamun Square and Myeong-dong in central Seoul, as well as Busan's Haeundae Beach area, and plans to announce a third round of designations this year.

As of 2025, the area around Coex had 20 outdoor advertising displays in operation, while Myeong-dong and Gwanghwamun Square each hosted digital screens larger than 1,200 square meters on building exteriors.

Advertisements appear on digital billboards around Gwanghwamun Square in Jongno District, central Seoul, Thursday. Korea Times photo by Shim Hyun-chul

Meanwhile, complaints related to light pollution have been on the rise.

According to the Ministry of Climate, Energy and Environment, the average annual number of light pollution complaints between 2014 and 2018 stood at 5,730, but climbed to 7,204 from 2019 to 2022 — an increase of 26 percent.

In Seoul, 8,078 light pollution complaints were filed from 2020 to 2024. Advertising lighting, including electronic billboards, accounted for the largest share at 3,194 cases.

“When billboards suddenly become very bright at night, it interferes with driving,” said Kim Pyo-mun, a taxi driver in his 70s, adding that blue light is tolerable but white light can significantly impact road visibility.

Kim Dong-woo, a 31-year-old photographer, said people around him have raised concerns about the large digital billboards installed across central Seoul in recent years.

“When those large billboards light up at night, they obstruct drivers’ visibility, not just cause glare,” Kim said.

Outdoor advertising regulations defer brightness and color standards to local ordinances. In Seoul, the brightness of outdoor digital billboards is capped at 1,500 candelas per square meter after sunset in commercial areas and 1,000 in residential neighborhoods.

When asked how officials check whether billboards exceed those limits, a city government team in charge of cityscape policy told The Korea Times that they measure luminance through on-site inspections, but added that these are not carried out on a regular basis.

An advertisement plays on a digital billboard at Shinsegae Department Store in Jung District, central Seoul, Thursday. Korea Times photo by Shim Hyun-chul

The issue has also been raised at the Seoul Metropolitan Council.

Last year, city council member Choi Jae-ran said during a session on regulatory reform that the recent installation of large LED billboards in the Gwanghwamun area worsened light pollution and left residents increasingly fatigued.

Choi In-kyu, head of the city’s Design Policy Bureau, said Seoul is monitoring the issue and acknowledged that the current maximum brightness limit of 1,500 candelas could be excessive.

“Our review shows that 700 candelas or lower is what people perceive as appropriate,” Choi said, adding that the city plans to draft specific guidelines for free-display zones this year.

The cityscape policy team added that it is conducting luminance measurements and other assessments to set the standards.

Experts say light from outdoor digital billboards can pose a hazard for nighttime driving and that current brightness limits should be lowered.

“If an overly bright light suddenly enters a driver’s field of vision at night, it causes the pupil to constrict and can reduce visibility,” said Choi Jae-won, a professor at the Korea Road Traffic Authority.

The professor stressed the need to control outdoor digital billboards’ light levels for nighttime driving, comparing the effect to the momentary loss of visibility when an oncoming vehicle’s headlights shine directly into a driver’s eyes.

“If the billboards are found to affect drivers at night, the city should revise its ordinance and lower the current 1,500-candela limit,” he said.