Drivers hitting the roads Tuesday, Chuseok Day, are expected to hit heavy delays, especially on Seoul-bound lanes, as many return from visiting family in their hometowns.
Some of the worst congestion was reported on spans of the Gyeongbu Expressway and the Seohaean Expressway, according to the Korea Expressway Corporation.
It was predicted that some 5.2 million vehicles would take to the roads throughout the day.
The estimated drive time as of 6 p.m. for people leaving Busan for Seoul was 6 hours, from Gwangju around 5 hours, from Daegu to Seoul 5 hours and for those departing from Gangneung 3 hours.
Road authorities said traffic would likely be jam-free after 1 a.m. on Wednesday.