South Koreans will enjoy a five-day holiday stretching until next Wednesday, as the country celebrates Chuseok, or Korean thanksgiving.
Traditionally, to celebrate a good harvest, Koreans visit their hometowns for a feast with their families, or visit their family's graves.
Some people started their journeys as early as Friday, with more than 36 million people estimated be on the move during the entire holiday period.
That's about 70 percent of the country's total population.
The Korea Expressway Corporation expects an average of 4.5 million cars to use the country's highways each day during the break.
Driving out of Seoul, congestion is expected to be the worst on Sunday morning, while on the way back, it's expected to peak on Monday evening, the day of Chuseok.
Between Sunday and Tuesday, tolls on the expressways will be waived.
Some will take the chance to travel abroad. Roughly 1.2 million people are expected to use Incheon International Airport, the country's main gateway.
And to cope with the sharp increase of people on the move during the holiday period, the transport ministry will be implementing special transportation measures, including more buses on inter-city routes and more frequent trains and inter-city planes within safe limits.
Kim Min-ji, Arirang News.