This is the 13832nd most frequent Korean word.
막히니
"막히니" means "is blocked" or "is jammed."
막히니 is used here as a condition or explanation for why one should take action.
요즘 출근 시간에 도로가 많이 막히니 대중교통을 타세요.
These days, since the roads are often congested during rush hour, consider using public transport.
막히니 indicates the reason or cause for the potential delay.
차가 막히니 좀 늦을 것 같아요.
Since there is heavy traffic, I might be a bit late.
막히니 is used to describe a situation being impeded that requires a response.