MBTA Red, Orange, and Blue Lines introduced countdown locks in early 2014, and the Green Line introduced them the following year. The eastern end of the Green Line introduced clocks in early 2016. They reflect how many "stops away" the train is, rather than how many minutes it will take to arrive. Amtrak has deployed PIDS throughout the Northeast Corridor. , PIDS are being deployed with unified messaging, which can include information streamed to mobile devices, phones and translated directly to voice announcements. Text to Speech products have been designed to convert PIDS data to speech in a choice of over 20 languages. See also General Transit Feed Specification Identification of Fixed Objects in Public Transport (IFOPT) IEEE Intelligent Transportation Systems Society Journey planner Platform display Real Time Information Group (RTIG), UK organisation Service Interface for Real Time Information (SIRI), technical specifications and standards Transmodel, CEN European Reference Data Model References Travel technology