After an 11-year wait, Seoul's 31st bridge across the Han River opened on Wednesday.
The World Cup Bridge crosses the river in the west of the city.
On the same day, the Seobu Underground Expressway opened as well.
It runs for more than ten kilometers underneath.
The underpass can carry around 50-thousand cars a day, and officials say that along with the new bridge, it will cut a 30 minute journey to just 10 minutes.
The underground road is free for the first two weeks and afterwards will have a toll of about two U.S. dollars.