Passenger information systems (PIS)
A passenger information system (PIS) is an onboard subsystem that delivers real-time journey information to passengers through visual displays and audio announcements throughout a train service.
A PIS consists of display units, an audio system, a control server, and data interfaces. Interior displays show next stop, terminus, route map, connection information, and service status.
System architecture
Exterior displays show destination and route number. Public address speakers deliver automated announcements, with automatic volume adjustment based on ambient noise levels.
The control server receives position data from the Train Control and Management System (TCMS) — typically via wheel-pulse odometry and GPS — and uses this to trigger location-based announcements and display updates.
The PIS interfaces with the TCMS for door status, speed, and time data. Integration with onboard closed-circuit television (CCTV) systems allows passenger emergency call locations to be relayed to the surveillance system.
On vehicle types with multiple compartment zones, the system supports targeted announcements to specific saloon sections independently.
Display technology
Thin-film transistor (TFT) LCD and LED-backlit displays have replaced the flip-disc and LED-matrix units common in rolling stock produced before 2005. Exterior destination signs require high-brightness panels to remain legible in direct sunlight; brightness specifications are set at procurement level.
All electronic display and control hardware must meet EN 50155:2017, which specifies operating temperature ranges (typically OT3: −25°C to +70°C), power supply interruption tolerance, shock and vibration resistance per EN 61373, and EMC limits under EN 50121-3-2.
Accessibility requirements
TSI PRM (Technical Specification for Interoperability relating to Persons with Reduced Mobility — Commission Regulation (EU) No 1300/2014, as amended by 2023/1694) requires that onboard PIS provide both visual and audible announcement of at least the next stop, the terminus, and any service disruption.
Display contrast ratios and character heights are specified to ensure legibility for passengers with visual impairments. Audio announcement clarity requirements address background noise levels typical of high-speed operation.
Data sources and management
PIS data is maintained in an off-board management platform, typically cloud-hosted, through which operators configure timetables, route information, and real-time updates. Real-time data exchange uses interfaces to national traffic management systems.
PIS electronics have a significantly shorter service life than the vehicle body; modular replacement without structural modification is a standard procurement requirement for new rolling stock.