Janb, I was stationed in South Korea twice, in the 1970's, so I'm afraid I don't have updated info. But I was able to get around fairly well on busses and trains "down country" Be careful with spoken Korean, as many town names sound alike to American ears...
. I found their public transport very clean and reasonably priced. I also found that, when I bought a bus or train ticket and started to compare the writing on my ticket, a Korean would quickly stop, look at my ticket and point to the right gate. And were gone before I could say "Ko mop sum ni da"!
HankDfromSD, you're right about Chin Hae! I'll never foret that flower-covered hillsdie as we made our way down ino the city on our bus tour from Kunsan!