Putting aside the specifics of the system in China, the underlying issues are a problem all countries need to explore. On many near capacity public systems it only takes a few bad actors to completely foul things up for entire sections, eg delaying a subway line. Traditional social pressure seems not to work anymore, for instance with this case on a train in the UK: https://youtu.be/2mpKu_x2s3w In that case the train was delayed until eventually the guard said they had to allow the smoker to stay on the train or it would affect the line! Part of their argument was there were no signs saying you couldn't smoke on the train (smoking is illegal inside in any public spaces!)