The district office of Seocho-gu in southern Seoul has removed all utility poles across Gangnamdaero, officials said Friday.

Gangnamdaero is a 7.2-kilometer, 10-lane main road connecting the northern and southern part of the district, and is among the busiest roads in South Korea. It is adjacent to the commercial district of the affluent Gangnam region, along with Gangnam Station and Yangjae Station, among the most populated subway stations here.

The district office said it just completed the three-year project to replace all of the overhead cables in the area for electricity and communications with underground cables -- a process called undergrounding in civil engineering -- having removed the last of the utility poles in the 530-meter section between Yeomgok intersection and Yangjae Citizen's Forest Station.

"We will continue with our undergrounding project, so that the people can walk safely on a road with clear skies above them," said Jeon Seong-soo, chief of the district office.

Seocho-gu has among the highest ratio of undergrounding in Seoul, at 74 percent compared to the city average 56.9 percent. It plans to spend 4.56 billion won ($3.5 million) next year on undergrounding projects near schools.