There are several ways you can get to Ulsan, and it is recommended to take the following route:
From Incheon Airport to Seoul Station: Express Train of Airport Railroad (i.e., AREX)
From Seoul Station to Ulsan Station: KTX (Korea Train eXpress)
It is faster than any other transportation and easy to make a reservation via app.
If you take “Express Train” at Incheon International Airport, it is recommended to take the following route, shown on the right figure:
① Incheon Int’l Airport
② Seoul Station
③ Ulsan Station
④ UECO
A document including the detailed instruction will be provided soon.