Slated for demolition: Seosomun Overpass, a 59-year-old structure in Seoul, within the upcoming month.
The city government of Seoul has announced plans to demolish the aging Seosomun Overpass and construct a new one, starting from August 2025. The demolition is set to begin on August 17, 2025, with a phased lane closure, and the overpass will be completely shut down on September 21, 2025. The new overpass is expected to be completed by February 2028 [1].
The Seosomun Overpass, built in 1966, has been carrying over 40,000 vehicles daily. However, inspections revealed significant deterioration, leading to a Grade D classification, declaring it structurally unsafe [1]. The city government determined that the demolition was necessary due to multiple issues over the years, including concrete spalling, rebar corrosion, floor slab spalling, and concrete and reinforcing wire damage.
During the demolition period, traffic will be affected in phases to reduce congestion. One lane from City Hall to Chungjeongno will close on August 17, and the opposite direction lane will close on August 24. The entire structure will close on September 21, 2025, when demolition work will be fully underway [1]. Special measures and cooperation with relevant agencies will be implemented to minimize traffic inconvenience due to concerns about congestion.
To help navigate the changes, notifications will be made via the official website, on-site banners, posters, electronic traffic signs, and social media channels. Online guidance will also be provided through navigation systems and traffic applications. Drivers are advised to avoid using Seosomun-ro and take other routes such as Sajik-ro, Saemunan-ro, or Saejong-daero.
In an attempt to reduce traffic congestion, the city government is planning to turn 20 Incheon and Gyeonggi Province-based buses back before entering the city's central area. However, no new bus routes have been decided yet. The city government has asked for the public's understanding due to the reduction of traffic lanes from August to September.
Following demolition, construction of a replacement overpass will begin. The construction is scheduled to start in May 2026 and is expected to take approximately 20 months [1]. The estimated demolition period for the Seosomun Overpass is 10 months, with completion expected by May 2023.
[1] City of Seoul, "Seosomun Overpass Demolition and Reconstruction Plan," City of Seoul Official Website, [accessed 2022-08-10].
- The city government anticipates potential finance challenges during the Seosomun Overpass demolition and reconstruction, as they plan to fund the project mainly through the industry sector's contributions and bank loans.
- In the new overpass design, a state-of-the-art transportation system will be integrated, including dedicated bike lanes, electric vehicle charging stations, and smart traffic management systems to enhance the city's infrastructure in the finance and transportation sectors.
