Seoul's 5th Subway Line Extension: What Does the Kimpo-Gumdan Project Mean for Commuters?

[iNews24 reporter Lee Sang-wan] The project to extend Seoul Metro Line 5 from Banghwa Station through Geomdan, Incheon, to the Gimpo Hangang 2 public housing district has passed its preliminary feasibility review.

Gimpo City said on the 10th that the Ministry of Strategy and Finance’s Fiscal Project Evaluation Committee gave final approval today for the Line 5 Gimpo–Geomdan extension’s preliminary feasibility review.

With that approval, the Line 5 Gimpo–Geomdan extension moves into the implementation phase, and Gimpo will gain its first direct heavy-rail connection to Seoul.

Calls for the Line 5 extension have been raised for more than a decade. The Ministry of Land, Infrastructure and Transport announced the project in 2022 as part of regional transport improvements tied to the “Gimpo Hangang 2 Compact City” development, and momentum grew after Seoul City, Gangseo District and Gimpo City signed a memorandum of understanding to advance the extension.

Since the Korea Development Institute (KDI) began the feasibility review, Gimpo City held more than 30 meetings and working sessions to develop a viable alternative. In April last year—before the ministry’s first review meeting—the city successfully argued to apply non-capital-region criteria to the assessment.

At the same time, the city secured recognition of demand tied to the Gimpo Environmental Regeneration Innovation Complex project. When the government delayed its review announcement by more than six months, Mayor Kim Byung-soo pledged ₩550 billion (about $412.5 million), and a National Assembly petition led by Gimpo residents topped 50,000 signatures, producing a dramatic turnaround.

On the 5th, Mayor Kim personally appealed to the KDI subcommittee, pressing the case for Line 5 until the end.

At a press conference he called the result “a miracle made by 510,000 citizens” and thanked residents for coming together as “one team” to make it happen.

“This is just the beginning,” he said. “We will protect Gimpo’s interests in future Line 5 discussions.” He pledged the city will devote the next two years to adding stations while carefully overseeing basic planning, design and the start of construction to accelerate completion.

Gyeonggi Province will lead the feasibility study and basic planning for Line 5. Officials expect work to begin in the second half of this year after the province secures supplemental funding and issues contracts. Over at least the next two years, the city will focus on adding stations residents have requested, including Pungmu 2, Gimpo Police Station and Tongjin Station.

The city emphasized it will not allow route adjustments that increase stops in Incheon at the expense of Gimpo residents’ travel time. Once routes and stations are finalized and the total project cost is agreed, officials will hold a public hearing. After that, they will move through basic and detailed design, compensation, construction start and completion.

Mayor Kim said he will ensure smooth follow-through on Line 5 and implement short-term measures—such as dedicated bus lanes and expanded service on Bus No. 70—to improve transit for Gimpo residents.

He added the city will steadily pursue broader goals to complete the regional rail network, including the Sinjeong spur of Seoul Line 2, extensions of Incheon Line 2, and an extension of Seoul Line 9.

The Line 5 Gimpo–Geomdan extension will run from Seoul’s Banghwa rail depot through Gochon, Pungmu and Geomdan in Gimpo to the Gimpo Hangang 2 public housing district. It will span 25.8 km (16.03 miles), include nine stations and one rail yard, and carry an estimated cost of ₩3.5587 trillion (about $2.67 billion USD).