The Boston area MBTA is the latest to add “quiet cars” on its commuter rail lines with a 3-month pilot starting in January. Library etiquette is expected of riders in the designated cars. Signs, conductors, and other passenters reinforce the silence of no phone calls and loud conversations. Amtrak pioneered the concept 10 years ago, though Metro-North (NY-CT) was the first to consider it (critics shot it down as a violation of free speech). Now Philadelphia, New Jersey, and Chicago are also using or testing out quiet cars.