From what I remember, it is originated from parents dropping their kids off at school. They don't have to park the car, they just need to pull up to the curb and they can just "kiss" their kids goodbye and "ride" away. So, in another words, it means this area is designated as a "drop off" area where you drop off your passengers.
Now, going back to this sign in Taiwan's HSR station, the usage is correct and it is probably understood by many foreigners who speak English in Taiwan. Even though Taiwan's population speaks some English, is it actually appropriate to be using such localized English in a such public setting? Especially you would have the situations that the passengers are business professionals, teachers, lawyers, and salespeople etc.
What do you think?