Chungnam, Optimal Construction of the '2nd Seohae Bridge' Undersea Tunnel

Route (plan) data comparing and reviewing four construction plans for the 'Second Seohae Bridge.' Provided by Chungnam Province

[Asia Economy (Hongseong) Reporter Jeong Il-woong] The route for the ‘2nd Seohae Bridge’ has been identified as Dangjin Anseom Port to Hwaseong Namyang Lake, with construction via an underwater tunnel deemed optimal according to a recent survey.

On the 11th, Chungnam Province announced that it had reached this conclusion through the recent ‘Preliminary Feasibility Study for the Construction of the 2nd Seohae Bridge.’

The study was conducted following the 2020 Chungnam Research Institute’s research on the ‘Necessity and Promotion Plan for the 2nd Seohae Bridge’ and the incorporation of the ‘4th Chungcheongnam-do Comprehensive Plan (2020?2040).’ It included basic data surveys, traffic demand, and economic feasibility analyses.

The study compared four routes involving sea bridges and underwater tunnels: ▲Dangjin Seokmun National Industrial Complex to Hwaseong Gungpyeong Port, 18.9 km (Option 1) ▲Dangjin Seonggumi Port to Hwaseong Bonghwa Intersection, 16.2 km (Option 2) ▲Dangjin Anseom Port to Hwaseong Namyang Lake, 8.4 km (Option 3) ▲Dangjin Hanjin Port to Seopyeongtaek IC Intersection, 10.6 km (Option 4).

Among these four options, Option 3 was found to be the most advantageous in terms of economy, traffic, construction, and safety. This route primarily involves constructing 7.48 km of underwater tunnel out of the total 8.4 km, with 0.92 km connecting roads.

The economic feasibility analysis (B/C) for the Anseom Port to Namyang Lake route was 0.87, higher than the average economic feasibility value (0.76) of projects that passed the ‘5th National Road and National Highway Construction Plan’ preliminary feasibility study conducted by the Ministry of Economy and Finance.

Considering policy evaluation and regional balanced development assessment, the province expects that the project’s implementation feasibility can be sufficiently secured.

So far, the 2nd Seohae Bridge has been continuously advocated for due to reasons such as shortening the distance along National Route 77 on the west coast, improving road connectivity, reducing logistics costs for industrial complexes in the northwest of Chungnam, and attracting new industrial complexes.

Additionally, the completion of the Boryeong Undersea Tunnel at the end of last year and the upcoming construction of the Garorim Bay Sea Bridge support the necessity of completing the west coast national coastal tourism industry road network, which underpins the need for the 2nd Seohae Bridge.

In particular, the Seohae Bridge frequently experiences congestion and requires full vehicle control during natural disasters such as strong winds and lightning, as well as large-scale traffic accidents, necessitating alternative detour routes.

Considering these circumstances, the province believes that constructing the 2nd Seohae Bridge as an underwater tunnel will be practical.

Most importantly, if the Anseom Port to Namyang Lake route is built as an underwater tunnel, the travel distance on National Route 77 from Songak Godae-ri in Dangjin to Ujeong Ihwa-ri in Hwaseong will be reduced from 46.4 km to 8.4 km, shortening by 38 km. The detour route used when Seohae Bridge is closed, ‘Seopyeongtaek IC → Asan Ho Embankment → Sapgyo Ho Embankment → Songak IC (35.5 km),’ will be shortened to ‘Seopyeongtaek IC → Underwater Tunnel → Songak IC (25.2 km),’ reducing travel time from 45 minutes to 20 minutes, according to the province’s calculations.

Furthermore, the daily traffic volume on Seohae Bridge is expected to decrease from 98,420 vehicles in 2050 to 85,325 vehicles, contributing to the alleviation of traffic congestion, the province anticipates.

A provincial official said, “It is expected that a long period of effort will be required to actively promote the construction project of the 2nd Seohae Bridge,” but added, “However, just like the Boryeong Undersea Tunnel, which started from the industrial tourism road network blueprint Chungnam drew 25 years ago, if the capabilities of 2.2 million residents unite, we expect to achieve results in the near future.”

This content was produced with the assistance of AI translation services.