I wrote to Train Link NSW back in 2019 requesting that a MLAK lock be fitted to the stations toilet on the platform. Cardiff is a station which isn’t staffed 24/7, and after a train ride from Sydney to Newcastle, most people, and anyone with a medical condition in particular would require access to the toilet prior to heading home.
I personally have been stuck with the dilemma of busting for the toilet and met with a locked toilet door.
It’s unclear at time of writing if this request was ever honoured, however I think its important this be published.
Alternative facalities are on Myall Road, or via Cardiff Shops (Not 24/7) and Iron Horse Cardiff.