Aging Seosomun Overpass to be Demolished Starting Next Month... Lanes to be Sequentially Closed (Comprehensive)

Full Closure on September 21... New Construction After Demolition Completed Next May

Demolition Inevitable Due to Safety Issues... Oh Se-hoon "Minimize Inconvenience During Construction"

Location map of Seosomun Overpass [Provided by Seoul Metropolitan Government. Reproduction and database prohibited]

(Seoul=Yonhap News) Reporter Jeong Soo-yeon = Seoul City announced on the 29th that it will demolish the Seosomun Overpass, built in 1966 and having reached the end of its lifespan, starting at midnight on August 17.

The Seosomun Overpass is a 335m long and 14.9m wide road composed of 18 piers connecting Chungjeongno Station and City Hall Station. Currently, over 40,000 vehicles pass through it daily on average.

The decision to demolish was made due to safety reasons.

The Seosomun Overpass experienced detachment of pier and slab concrete and corrosion of reinforcement in 2019 due to wire breakage inside and outside the beams supporting the bridge deck and degradation of concrete strength throughout the entire section.

A detailed safety inspection resulted in a 'D grade' rating, indicating a lack of safety. Since then, damage such as floor slab detachment (2021), beam concrete detachment, and beam wire breakage (2024) has repeatedly occurred.

The city has been investing approximately 800 million to 1 billion won annually for maintenance and management, including installing concrete fall protection nets, repairing piers, restricting heavy vehicle traffic (30t → 20t → 10t), and operating monitoring equipment. However, it determined that simple repairs were no longer sufficient and ultimately decided on demolition.

Demolition will proceed by sequentially reducing lanes to minimize inconvenience to citizens and alleviate traffic congestion.

On the 17th of next month, one lane from City Hall → Chungjeongno direction will be closed first, and an additional lane from Chungjeongno → City Hall direction will be closed starting on the 24th.

The number of lanes from Chungjeongno Station → City Hall Station will be reduced from the current 4 lanes (2 overpass lanes, 2 ground lanes) to 2 ground lanes, and from City Hall Station → Chungjeongno Station from the current 3 lanes (2 overpass lanes, 1 ground lane) to 1 ground lane.

Starting at midnight on September 21, the overpass will be fully closed for full-scale construction. The construction period is expected to be approximately 10 months, with demolition completion targeted for May of next year.

Of the 43 bus routes currently passing through Seosomun-ro, 20 intercity bus routes will be detoured starting on the 17th of next month.

11 Incheon bus routes will turn back at Hongik University Station, and 9 Gyeonggi bus routes will attempt to minimize entry into the city center and detour via Tongil-ro, Sajik-ro, and Saemunan-ro.

Some of the 23 Seoul city bus routes are planned to detour via surrounding roads starting September 21, but early detours may be implemented depending on changes in the traffic system and traffic conditions.

Approximately 10% of the vehicles using the Seosomun Overpass are buses.

Given the expected traffic congestion, the city urges general vehicle drivers to avoid Seosomun-ro as much as possible and to detour via surrounding roads such as Sajik-ro, Saemunan-ro, and Sejong-daero.

Nearby detour routes [Provided by Seoul Metropolitan Government. Reproduction and database prohibited]

Vehicles traveling from Mapo-gu to Jung-gu can enter the Sejong-daero direction via Sajik-ro when using Seongsan-ro, via Chungjeongno (Saemunan-ro) when using Sinchon-ro, and via Chilpae-ro when using Cheongpa-ro.

Vehicles traveling from Jung-gu to Mapo-gu can use Sajik-ro and Seongsan-ro from Sejong-daero, or use Saemunan-ro and Chungjeongno, or Cheongpa-ro, or Mallijae-ro.

After the demolition is completed next May, Seoul City plans to immediately commence construction of a new overpass. The new construction is expected to take approximately 20 months, with completion targeted for February 2028.

Ahn Dae-hee, head of the Seoul Metropolitan Facilities Management Corporation, stated, "The Seosomun Overpass is in a state where citizen safety cannot be guaranteed, making demolition an unavoidable measure." He added, "Traffic congestion is expected during the construction period, so please refrain from using Seosomun-ro and use public transportation."

On the 28th, Seoul Mayor Oh Se-hoon inspected the Seosomun Overpass site and urged, "Significant inconvenience due to traffic congestion during the demolition period is a concern, so special measures are needed." He instructed, "Make every effort in cooperation with relevant agencies to minimize traffic inconvenience during construction." Yonhap News