With vacation season in full swing in South Korea a number of expats and other travelling bodies find themselves in need of transportation to Incheon International Airport. Fortunately, public transportation is rarely an issue in South Korea so getting to the airport is of little difficulty.
If you are beginning in Daejeon you have essentially two options: 1) Train (slow ~10,000 W/2 hours or KTX ~20,000 W/1 hour) to Seoul station followed by the Airport express (~4,000 W/45 minutes) to Incheon International airport or 2) Direct bus from Daejeon Dunsan (maybe aka Dong-bu) Bus Terminal (22,000 W/2.5-3hours). Either option lands you right at the front door of the airport for vacation adventures to begin!
And upon returning to Incheon one can easily back track option 1 looking for the Airport express line to Seoul station before returning to Daejeon or by looking for the following counter which is just outside of baggage claim and can hook the traveler up with a ticket to just about anywhere on the peninsula.