Perhaps "next station, Vila Isabel" or ''transfer to (the name of the station".
Can´t be sure, let´s wait for some user of that Metro have a say, or perhaps someone else have already solved the "puzzle" to you while in the ride.
Or it is something having to do safety, don´t know. I learned that in London they warn ''mind the gap between the train and the platform". So, it could be, for instance, something like "be assured/ be sure that...some kind of safety announcement or warning to passengers not to leave their cellphones or personal belongings behind.
Rio Metro users, anyone? http://mic-ro.com/metro/announcements.html