The mass exodus from Seoul that heralds the start of the Chuseok holiday has begun, with vehicles already starting to cram major highways a day ahead of the holiday break.

The Korea Expressway Corporation said that as of 2 p.m. Wednesday, the usual four-and-a-half hour trip from the capital of Seoul to the southern port city of Busan now takes an estimated six hours and 50 minutes.

Driving to cities in the southwest will likely take around five and a half hours, while a trip from the capital to the eastern coastal city of Gangneung in Gangwon Province should take roughly three hours.

The road authority forecast that some 530-thousand vehicles will travel from the Seoul metropolitan area to other regions and around 470-thousand will depart from provincial regions bound for the capital area on Wednesday alone.

The corporation projected that roads will see heavy traffic congestion between 6 and 7 p.m. Wednesday with the Chuseok exodus overlapping with rush hour.