Mmmmhhhhh it's gonna be TIGHT. If you are in T2 (Korean Air/Delta Skyteam), it's much more likely - you can be in and out of that terminal quickly. You should take the bus over a taxi. The bus actually is MORE comfortable (spacious seat) compared to a small taxi....and the bags go under the bus easy.
When you arrive, there are TWO buses you could take to eliminate the wait. 6703 is KE Limo bus. BUT if you are at T1 - that bus will go by T2 to pick up first, adding 20 minutes. From T2 it goes right to Gangnam.
If you are at T1, take 6103
https://www.calt.co.kr/lang/en/conte...4.php?b_n=6103 . as this goes to the COEX CALT complex right next to the Intercontinental. This bus goes directly from T1 to Gangnam.
Gangnam resident here that takes buses only to airport. Train is a pain in the a**. No bag storage, Line 9 express CROWDED and it's just FAR. Absolutely expect bus to be 1-1.5 hrs normally, at the worst 2 hrs. Incheon Airport is just F'ing far away and not much to do about it. If you take a taxi, they sit in the exact same traffic.
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