'Sinwol-Yeoui Underpass' Opens at Midnight on the 16th... Sinwol to Yeouinaru Reduced to 8 Minutes

Sinwol IC~Yeouido-dong Yeouidaero·Olympic-daero 4-lane bidirectional underground tunnel with a total length of 7.53 km
Commute time reduced from 32 to 8 minutes, toll 2400 won... Speed limit 60~80 km/h

[Asia Economy Reporter Lim Cheol-young] The ‘Sinwol-Yeoui Underground Road’ (formerly Seoul Jemulpo Tunnel), directly connecting Sinwol IC in Sinwol-dong with Yeouidaero and Olympic-daero in Yeouido-dong, will open at midnight on April 16.

The Sinwol-Yeoui Underground Road is a four-lane (two lanes each way), deep underground tunnel with a total length of 7.53 km, directly connecting the southwestern area of Seoul (Sinwol IC) with the city center (Yeouidaero, Olympic-daero). It is located 50 to 70 meters underground beneath Gukhoe-daero. It took 5 years and 6 months (66 months) since groundbreaking in October 2015.

The ‘Seoul Jemulpo Tunnel Private Investment Project’ is a revenue-type private investment project (BTO, Build Transfer Operate) where a private operator constructs the tunnel according to the implementation agreement signed in May 2014, transfers ownership to the Seoul Metropolitan Government upon completion, and operates it directly for 30 years to generate revenue through tolls. There is no minimum revenue guarantee to compensate losses with taxes if profits are low.

Using the Sinwol-Yeoui Underground Road reduces commuting time from Sinwol IC to Yeouido from the existing 32 minutes to 8 minutes during peak hours, cutting 24 minutes. The toll is 2,400 KRW, and the speed limit is 80 km/h (60 km/h at the Yeouidaero and Olympic-daero entry and exit points). It is a road exclusively for small vehicles, allowing passenger cars of compact, small, medium, and large sizes, and vans with up to 15 seats and dimensions not exceeding 1.7 m in width and 2.0 m in height.

To minimize inconvenience to users of Gukhoe-daero and local residents, the tunnel was constructed using the NATM (New Austrian Tunnelling Method), which involves blasting and excavation followed by spraying concrete on the walls to harden, instead of the cut-and-cover method.

Notably, the country’s first unmanned toll collection ‘smart tolling’ system has been introduced. Vehicles using the tunnel are automatically charged tolls through Hi-Pass, Seoul City’s Baro Green Payment, and pre-registered video agreement services. The pre-registered video agreement service charges tolls by recognizing vehicle license plates without a separate device and can be easily applied for free on the ‘Sinwol-Yeoui Underground Road’ website.

The Sinwol-Yeoui Underground Road is equipped with evacuation and disaster prevention facilities rated at least grade 1 for disaster prevention, prepared for emergencies such as fires. Considering the urban environment, a ‘By-Pass’ ventilation system that purifies and does not discharge fine dust and harmful gases inside the tunnel has been adopted.

Evacuation facilities include 25 pedestrian-only shelters spaced every 200 meters and 15 combined vehicle and pedestrian shelters spaced every 600 meters, totaling 40 evacuation routes. Disaster prevention facilities include indoor fire hydrants, fire extinguishers (within 44 meters), connection fire water supply equipment, water spray systems, smoke control systems (also serving as ventilation), and evacuation communication doors.

In case of fire or other accidents, automated fire detection and video anomaly detection systems automatically detect fires. Within 5 minutes, smoke is concentratedly discharged by the smoke control system and water spray system. When entry of vehicles is restricted, users can evacuate to the opposite tunnel and then move on foot through six entrances/exits or use two vertical shaft elevators for evacuation.

As a long deep tunnel, the latest traffic management system has been installed for driver convenience. There are 18 vehicle detectors (VDS) to monitor traffic conditions, 3 variable message signs (VMS) and 22 queue warning signs (QWS) to inform drivers, and 39 lane control systems (LCS). These operational facilities are automatically controlled and monitored in real time from the integrated control room. Speed cameras for section and point enforcement are installed inside the tunnel to help ensure safe driving.

After opening, it is expected that the existing traffic system near the Sinwol IC, Yeouidaero, and Olympic-daero entrances and exits will not be significantly affected. Continuous traffic monitoring will be conducted to establish improvement measures for any issues that may arise. Gukhoe-daero, which is extremely congested with up to 190,000 vehicles daily, is expected to see a reduction of about 50,000 vehicles due to the opening of the Sinwol-Yeoui Underground Road, improving commuting convenience for citizens and contributing to better air quality.

The opening of the Sinwol-Yeoui Underground Road will also change the surface landscape. Above the underground road, a four-lane (two lanes each way), 4.1 km long ‘Gukhoe-daero Underpass’ connecting Sinwol Interchange to Mokdong Sports Complex will be constructed by 2024, creating a three-level road structure. The surface will be transformed into a large-scale eco-friendly linear park of about 110,000 square meters?five times the size of Gwanghwamun Square?and a residential road (1-2 lanes) by 2025.

On April 15, one day before the official opening, Seoul City will hold an opening ceremony at the Sinwol-Yeoui Underground Road exit in front of the Yeouido Federation of Korean Industries building. Seoul Mayor Oh Se-hoon, Yeongdeungpo District Mayor Chae Hyun-il, Yangcheon District Mayor Kim Soo-young, Gangseo District Mayor Noh Hyun-song, local National Assembly members, and city council members will attend.

Seoul Mayor Oh Se-hoon said, “The Sinwol-Yeoui Underground Road is a monumental underground road born with many ‘firsts’ in various aspects. As Korea’s first underground expressway integrating cutting-edge smart technologies in mobility, convenience, environment, safety, and traffic management, I am confident it will elevate the quality of life for citizens to a new level.”