A time slot without congestion?

When crossing from Seoul to Gyeonggi Province

What time does it start based on the non-peak hours (morning)?

I plan to go from near Gangnam, Seoul, to Yangpyeong in Gyeonggi Province after 9 o'clock.

It will probably get clogged, right...? I feel anxious for no reason ㅠㅠ

It seems that Seoul is always congested regardless of the time on weekdays ㅠㅠ