Chuseok, the Korean equivalent of Thanksgiving, is one of the country's biggest traditional holidays and serves as a chance for family members to get together to give thanks and pay tribute to their ancestors by preparing them meals and visiting their graves.
Chuseok is celebrated on Aug. 15 in the lunar calendar, which falls on Friday this year.
According to the Korea Expressway Corp., about 5.17 million vehicles were expected to use highways Thursday alone.
"It appears that the region-bound traffic, which began yesterday, will continue through the night," an expressway corporation official said, adding that the heavy traffic is expected to begin easing around 7-8 p.m.
The Seoul-bound traffic is expected to become heavy around 9-10 a.m. Friday, the official said.
As of 9 a.m., it took about eight hours to get to the southeastern port city of Busan from Seoul; seven hours to the city of Daegu; 6 1/2 hours to the southwestern city of Gwangju, and four hours and 40 minutes to the central city of Daejeon. (Yonhap)