Public transport is not the best social environment you can think of. Staring, reading, silence, and nowadays playing with a smartphone is what most travelers do.
In Brazil they came with a new kind of priority seats to break this daily routine. You could call it social intervention 2.0 IRL.
These seats, marked with a label, are only available to people who wish to gain new experiences. For people who are ready for a new conversation.
For help to start a conversation some suggestions are given on post-its.