Under-road heating a lifesaver in Seoul's hilly communities

Under-road heating systems are saving many lives in Seoul's hilly districts, especially as heavy snowfall in subzero temperatures increases the risk of black-ice accidents nationwide...

A road installed with under-road heating system in Mount Namsan in Seoul on Dec. 20, contrasted on the right with a photo taken of the same with a thermal camera. [YONHAP]

Under-road heating systems are saving many lives in Seoul's hilly districts, especially as heavy snowfall in subzero temperatures increases the risk of black-ice accidents nationwide.

“We couldn’t run the maeul bus on these hilly roads whenever there was snow,” said a 61-year-old bus driver surnamed Yoo as he drove the green village bus up a hill in Seongdong District, eastern Seoul, on Thursday.

Temperatures dropped to as low as minus 14 degrees Celsius (6.8 degrees Fahrenheit) that morning, with the wind chill hitting as low as negative 22 degrees Celsius.

It snowed some 3 centimeters (1.2 inches) two days earlier — a condition that could have easily put the bus out of operation for that day.

As the only public transportation operating on narrow Dokseodang-ro road, which passes through several apartment complexes, the bus's cancellation might have inconvenienced thousands of residents.

Thanks to the under-road heating system installed on Dec. 1, that's no longer a concern.

The system, installed 5 to 7 centimeters below the road, automatically begins to heat the road whenever the temperature drops below 2 degrees Celsius. By heating it to 5 to 10 degrees Celsius, the road can melt 3 to 5 centimeters of snowfall every hour, according to the Seoul city government.

In recent years, local districts, especially those with hilly residential areas, began to identify high-risk areas under heavy snowfall and install segments of the under-road heating system.

A village bus driver drives through an area in Seongdong District, eastern Seoul, recently installed with under-road heating system on Dec. 21. [LEE YOUNG-KEUN]

According to the Seoul Metropolitan Government, the city installed 14 under-road heating systems in 2019, an addition of 151 in 2022 and another 161 — including the latest installment in Seongdong District — this year.

The city has 419 under-road heating systems covering 65.96 kilometers (40.9 miles) of roads.

Gangnam District in southern Seoul had the most at 56 systems, and Seongdong had the longest at 6,800 meters (22,309 feet).

Two districts have none — Yeongdeungpo District and Yangcheon District, both in western Seoul.

According to the Korea Road Traffic Authority, 4,609 traffic accidents caused by black ice have occurred in the past five years, resulting in 107 deaths and 7,728 injuries.

More than 70 percent of the accidents occurred between December and January, with the fatality rate about 1.5 times higher than on non-icy roads, according to the road authority.

Cab drivers have welcomed the increased installation of under-road heating systems.

“I started work at 4 a.m., and I’ve already seen four traffic accidents happen,” said taxi driver Yang Jeong-mo on the morning of Dec. 20 after overnight snowfall.

“They say it’ll be colder tomorrow, so I’m very worried about black ice,” he said. “The heated road systems are a lifesaver.”

Icy weather can be hazardous for the residents living in residential areas of Mount Namsan.

Jeong Hyo-won, who needs to climb the 22-degree slope of Pildong-ro road every day to get home, once slipped on the icy hill.

“I had to go to the hospital for two weeks after that,” she said.

The hill street got an under-road heating system in October last year.

A part of the Pildong-ro road in Jung District, central Seoul, installed with under-road heating system, on Dec. 20. [OH SAM-GWON]

However, not all district offices have been able to install the system, citing its costs. The average installation cost of the system is about 100 million won ($76,740) per 100 meters.

Local districts' disaster management funds cover the cost.

The Gangnam District Office said it paid 3.43 billion won to install 29 separate under-road heating systems this year. The electricity bill for operating 27 of them from January to March last year was 62 million won.

“As the budget is limited, the installation location is being decided based on how steep the slopes are, how shaded the area is, and the level of traffic passing through the area,” a Seoul city government official said.

Repeated black-ice accidents could be added as another category. An intersection in Cheongdam-dong has seen three black-ice accidents between 2018 and 2022, according to the Korea Road Traffic Authority. One person was seriously injured and four sustained light injuries in these accidents.

"The city government is in charge of the main road maintenance, and the local district office the side roads," said an official of the Gangnam District Office, adding that relevant side roads will soon be installed the under-road heating system.

Residential neighborhoods without the system rely on the younger residents to do the snow plowing work.

A 42-year-old resident of the hilly neighborhood of Haebangchon in Yongsan District, central Seoul, was spraying calcium chloride on the 3-meter-wide road in front of his house on the morning of Dec. 20.

He often volunteers to shovel snow in the area.

A road in the Haebangchon area of Yongsan District, central Seoul, on Dec. 20. [OH SAM-GWON]

“There are a lot of older people who live nearby, and every year, they slip and get seriously injured,” he said. “It would be nice to have the under-road heating system installed here as well, but I think our neighborhood is pretty low on the priority list because there isn't enough traffic there.”

Some district offices began installing heated sidewalks for the elderly and young population.

There are a total of 11 installed in Seoul, targeting areas such as bus stops on slopes and crosswalks at the entrances of elementary schools, including Oksu Elementary School in Seongdong and the bus stop in front of Yangjae Senior Welfare Center in Seocho District, southern Seoul.

“I was a little worried about the slope in front of the school, but I feel reassured because there's an under-road heating system,” said a 39-year-old woman who watched her first-grade son walk into Oksu Elementary School on Dec. 21.

Experts have called for more such systems as the country’s older population is only expected to grow.

“Countries with high aging rates, like Japan, are installing a lot of heated sidewalks,” said Jang Jin-hwan, a researcher at the Korea Institute of Civil Engineering and Building Technology. “These would be good examples to follow as we need to start thinking more about infrastructure for vulnerable members of society.”

BY LEE YOUNG-KEUN, ESTHER CHUNG [chung.juhee@joongang.co.kr]