I wondered -what on earth does that mean? And I wasn't even in Kings Cross, rather Chatswood!
What, you can't guess?
We have them here in Perth, too.
Usually they are places where the partner drops the spouse off for a train ride; standing only for cars - no parking places. A quick goodbye kiss and they're off for the day!
Most schools have a "Kiss and Drop" zone - usually supervised quite heavily. It keeps the traffic moving and ensures that kids aren't put at risk with parents double-parking etc
I haven't seen any (or noticed any) since I moved to QLD, but I'm not unfamiliar with them. The local bus/rail interchange in Salisbury SA close to where I grew up use to have them. I use to think they were funny when I was young but I knew what they were there for.