An unusually long holiday period begins on Friday, and congestion is already mounting on major highways.

Approximately 41-thousand vehicles were expected to exit Seoul on Thursday, while about 40-thousand were forecast inbound.

The Korea Expressway Corporation predicted that congestion would peak around 6 p.m., with routes into Seoul clearing up by 10 p.m. and outbound traffic easing after midnight.

Estimated drive times as of 5 p.m. were four hours 50 minutes to Busan and two hours 10 minutes to Daejeon from Seoul tollgate.

More than five-point-two million cars are expected nationwide on Friday, with holiday gridlock peaking at midday.

It's recommended that drivers check real-time traffic online before heading out.