SEPTA will begin Quite Cars for all its rail services beginning today. It is a set of regulations that will be self-enforced by peer riders on cell phone use, music listening and loud conversations. Of course, I applaud the SEPTA's decisions to implement Quite Cars. However, it is an interesting case study to apply System Thinking to predict its consequences.
It is easy to predict that it will have a positive impact. In fact, on NPR this morning, so-called an expert on commuter stress predicted that Quiet Car will be a major factor in reducing the commute stress. Noise being one of the key factors contributing to the stress, the expert argued that just knowing the availability of quite cars would reduce the commuters' stress level. At the same time, he also mentioned that crowdedness and delay are two other major factors. While his expert prediction seems to make sense on the surface, one can easily imagine undesirable impact once we consider feedback loop and other factors that contribute to the commuter stress. Here's how it might happen. Once people realize it is much more comfortable to commute in the Quite Car, most people will choose to ride Quite Cars. Since it is likely that SEPTA will assign only few cars as Quiet Cars, this will make Quite Cars overly crowded, while leaving non-Quiet Cars only to few noisy people. Therefore, individuals who prefer quite ride will face two undesirable choices. EIther they have to face the crowded Quiet Cars or they have to choose non-crowded but noisy cars. This undesirable impact will only be more amplified as Quiet Cars become more popular.
Therefore a sensible design choice is to get rid of non-Quiet Cars all together or to make Quiet Cars as default choices and leave only very few cars as non-Quiet Cars.