Seoul Expressways

The first expressway constructed in Seoul, and in Korea, was the Gyeongbu Expressway ( 경부고속도로, Gyeongbu Gosok-doro) that runs from Seoul to Busan. Construction began in 1968, and it opened in 1970. But that’s a national route. This page is about local routes that carry traffic through Seoul and its surrounding area.

The riverside expressways

Modernization of the Han River began in 1968. Through the ’70s and ’80s, the outlines of the river as we know it today began to take shape. Embankments were constructed through projects aimed at flood control and land consolidation. Bridges were built and Yeouido was developed. Early steps were taken to urbanize the riverfront. And two major expressways were built along its banks: the Gangbyeon on the north side and the Olympic on the south.

Gangbyeonbuk-ro (강변북로)

The Gangbyeonbuk-ro was the first Seoul-centric expressway constructed in Korea. It’s name translates as “North Riverside Road”, but it’s generally referred to as the Gangbyeon Expressway in English. Construction began in 1969 and continued in stages, with sections opening as follows:

In 1989, work began to extend it to its current length of ~37 km both to the west and the east. These final extensions were completed in 1998, with the eastern terminus in the city of Guri and the western terminus in the city of Goyang.

Olympic-daero (올림픽대로)

A massive amount of development took place south of the Han River and east of Yeongdeungpo District through the 1970s. What once was farmland had been transformed into the thriving Gangnam District. It encompassed the area that today comprises the districts of Seocho, Gangnam, and Songpa. This resulted in an influx of people and vehicular traffic.

Meanwhile, the city of Seoul was planning to host the Asian Games in 1986 and the Olympics 1988. Multiple venues for the games were being developed in eastern Gangnam, the area that would become Songpa District in 1988.

By the early ’80s, plans had emerged for a new expressway on the south bank of the river aimed at relieving traffic congestion in Gangnam and providing easy access to the Olympic venues. It was aptly named “Olympic Expressway” in English. Now and again, you’ll find references to “Olympic Boulevard” because of the decision to use the “-daero” suffix in the Korean name. Construction got underway in 1982. It opened on May 2, 1986, just in time for the Asian Games in late September and early October.

The Han River Comprehensive Development Framework launched in 1982 as part of the Korean government’s national water resource policies, initiating projects aimed at further addressing flood control, enhancing aesthetics, and dealing with environmental issues. By 1983, plans were cemented to improve embankments, create riverfront parks, and construct sewage treatment facilities and infrastructure for leisure and sports. Some of this work was carried out in parallel with construction of the Olympic Expressway.

Given that the expressway is located between today’s riverside parks to its north and residential properties to its south, a logical assumption is that the expressway was laid out with development of the waterfront in mind, despite having started construction before the Han River development plans were finalized in 1983. This is a stark contrast with the north bank, where the elevated Gangbyeon Expressway runs directly above land that was only later adapted to use for leisure and sporting activities, and where you’ll find much less usable green space next to the river.

The four (now five) arterials

Plans for four arterial roadways, two on an east-west axis and two on a north-south axis, were drawn up in the late 70s. I found a reference that the name of the southern arterial was established in 1978, so it seems safe to infer all four would have been planned around the same time.

They were named as follows:

Construction began on each at different times.

The Seobu Underground Expressway

In March 2015, a project began to bore a tunnel for a new roadway beneath the Seobu Expressway. This followed years of planning to deal with traffic congestion and flood risks along parts of the expressway that aren’t elevated, as the Anyangcheon sometimes overflows during the rainy season. The Seobu Underground Expressway (서부간선지하도로, Seobu Ganseon Jiha-doro, “Western Arterial Underground Road”) opened on September 1, 2021. It’s a toll road with four-lanes each way, and runs for around 10.33 km along the same corridor as the overground Seobu Expressway, which is still in operation.

The Dongbu Underground Expressway

When the Dongbu Expressway was originally constructed, it was expected that it would be flooded by the Jungnangcheon once every four years, and it does flood periodically. This was one of the motivators for the initiation of a project to build the Dongbu Underground Expressway (동부간선지하도로, Dongbu Ganseon Jiha-doro, “Eastern Arterial Underground Road”), which broke ground in 2024 after 15 years of planning and is anticipated to open in September 2029.

Currently, the surface route is understood to be fully on the north side of the river. Maps label a section of roadway on the south side of the river, following the Tancheon (Tan Stream) southward, as “Dongbu Ganseon-doro”, but most people refer to that southern corridor as either the “Tancheon Expressway” or the “Bundang Expressway”. Another motivator for the underground expressway is to tunnel beneath the Han River and connect the Dongbu’s route with Daechi-dong in southern Gangnam.

Unlike the situation with the Seobu, where the overground route is still in use, the Dongbu Underground Expressway is intended to completely replace the overground rout. The land will be repurposed in some way, most likely as a public park. Plans will be finalized once construction of the underground roadway is completed.

The Naebu Underground Expressway?

In 2024, research began on boring an underground expressway to replace the Inner Beltway. It hasn’t yet progressed beyond the stage of feasibility studies. Experience with the Seobu and Dongbu underground routes demonstrate that it can be done in theory, but we’ll have to wait a while to hear if it’s practical.

The Seoul Ring Expressway

The Korean government first envisioned a ring road to divert through-traffic away from Seoul in the late 1960s as part of one of Park Chung Hee’s Five-Year Economic Development Plans. At the time, it was just a conceptual thing intended to link the planned national expressways outside of the city core.

It wasn’t until the 1980s that concept became reality. As a result of explosive urban growth and increasing congestion on the Gyeongbu (Seoul to Busan) Expressway, the Ministry of Construction drew up plans for the “Seoul Outer Ring Expressway” (외곽순환고속도로, Oegwak Sunhwan Gosok-doro). Construction on the first segment, between Guri and Pangyo, began in 1988. By 2007, it was completely encircling Seoul, running through Goyang, Uijeongbu, Namyangju, Hanam, Seongnam, Gwacheon, Anyang, Bucheon, and Gimpo.

This expressway serves as a connector between the national highways in and around Seoul, the two riverside highways along the Han, and the four arterials.

In the 2020s, it was renamed to “Seoul Ring Expressway” in English, and 수도권제1순환고속도로 (Sudogwanje 1 Sunhwan Gosok-doro) in Korean, indicating it’s the first of multiple outer ring roads. It’s now being expanded with new outer rings, for example, 수도권제2순환고속도로 (Sudogwanje 2 Sunhwan Gosok-doro), though I don’t know what the names will be in English.

Mike from Korea References