It is a nice idea to set quiet carriages on trains: travellers switch phones to silent, turn stereos off and keep chatter to a minimum. However, there is usually at least one disgusting person to break the silence.

There are a couple of problems which prevent the silence trips. First is the carriage sorting problem. Some passengers sit in the quiet carriage by accident and are not aware of the rules. The second problem is the duty problem. Noise is sometimes made by travellers who choose the quiet carriage but find an important call hard to ignore.

Several ways are worked out to solve the problems above. One neat solution in theory is to fin people for making a noise, but it requires constant monitoring and enforcement. Another solution is to use prices to separate quiet and noisy passengers, which means creating a market for silence. A simple idea is to sell an optional extra access to the quiet carriage when the ticket is bought. Making the quiet coach both an active choice and a costly one would dissuade many of those who do not value a peaceful trip.