Originally Posted by mikesaidyes

With an ARC card, you can't get in the Korean passport lanes on your own, but you can use them if someone directs you to go there.

BUTTT you can use the automated fingerprint gates Smart Entry Service. I absolutely recommend it, always for this reason (arriving at ICN crowds). With ARC, there is no fee. Just sign up and go! You can sign up at ICN, GMP or even Seoul Station/Gangnam CALT Immigration counters. I got mine on an E-2 visa originally and now I have an F-2-7 resident visa.

Jsut be prepared for literally three random passengers in the automated line to stop you and say "this is for Koreans only." The staff know that foreigners can do it, of course, but the average Korean does not.

Originally Posted by mikesaidyes

And other foreigners can use Smart Entry Service depending on their country. For instance, Americans with Global Entry (no ARC card/Korean residence) can use the automated gates, but have to pay a fee and do an interview/application.

Those of us with ARC don't even fill out a paper. They just input your info in the system and place a sticker in your passport (valid for 5 years or until your visa ends/changes).