Turnstiles

James Murphy has composed a “Subway Symphony”—a unique set of notes for each station in NYC’s Metro system that would sound when users swipe their fare cards. “The busier a station becomes, the richer the harmonies would be.”
Feb 25, 2014   The Wall Street Journal
As Los Angeles MTA's plan to fully implement its TAP card program stalls, so does the plan to lock the turnstiles that the agency had installed to deter riders from not paying.
Aug 27, 2010   LA Daily News
Turnstiles are coming to the Los Angeles subway. Some say the move will help raise revenue for the city's transit authority, given its recent increases in ridership.
Sep 7, 2009   Next American City