Koreans tend to thank the driver whenever they step off the bus. Any bus. The bus could have gone a mile or it could have gone from Seoul to Mokpo, but the response would be the same: Thank you, thank you, and thank you. Everyone says it. I picked up the habit right away. These guys deserve the credit.*
There's a bit of culture for you. I can wait to thank my bus driver--I'm writing this on the iPad--when we pull into the Dong (East) Seoul Bus Terminal because he drove this Kia bus like a sports car. I mean it. Touring never gets boring here.
Semi-obligatory note on "guys": In nearly three years, I've yet to see a female bus driver, local or otherwise.
[I originally wrote this post a couple weeks ago, but the point stands.]