The Donghongcheon–Yangyang Section 15 construction project is a project involving a total length of 5.62 km, which includes 9 bridges, 3 tunnels, and 1 Seoyangyang IC. In particular, Gongsujeon Bridge—constructed using the Pre-stressed Composite Truss (PCT) method—is the longest bridge of its kind in South Korea (450.7 m), featuring an open truss structure with excellent aesthetics and majestic piers reaching up to 68.5 m in height.

