Passenger systems and interiors - the onboard experience as infrastructure
A passenger’s entire experience of a train — boarding, finding information, moving between cars, feeling safe — is delivered by a set of technical subsystems engineered, certified, and maintained as rigorously as the traction equipment beneath the floor.
Passenger-facing systems are sometimes treated as a finishing layer applied after the structural and mechanical design is complete. In practice, they impose binding constraints on vehicle architecture from the earliest design phase.
Interiors in the vehicle design process
Door positions determine body-section geometry and structural opening sizes. Gangway connections define the inter-car coupling envelope and influence aerodynamic sealing requirements at speed.
Passenger information displays require power routing, network cabling, and integration with the Train Control and Management System (TCMS). Closed-circuit television (CCTV) systems impose storage, bandwidth, and data-retention obligations that interact with cybersecurity frameworks.
The systems in this section are governed by a distinct regulatory layer that overlaps with but is not identical to the traction, signalling, and braking standards that dominate rolling stock certification.
The primary instruments are TSI LOC&PAS (Commission Regulation (EU) No 1302/2014, amended most recently by Implementing Regulation (EU) 2023/1694) and TSI PRM (Commission Regulation (EU) No 1300/2014, also amended in 2023), together with EN 50155:2017 — the base standard for all onboard electronic equipment — and a series of component-specific standards.
The TSI framework for passenger subsystems
TSI LOC&PAS addresses passenger-related items in clause 4.2.5, covering interior requirements that affect interoperability: step heights and gaps at boarding, gangway passage dimensions, door control logic, and glazing specifications.
The PRM TSI adds accessibility requirements applicable to both rolling stock and stations: passenger information displays must deliver both visual and audible output; boarding aids must meet specified reach-zone and force-limit parameters; toilet provision for wheelchair users follows defined dimensional criteria.
Both TSIs were amended by Commission Implementing Regulation (EU) 2023/1694 of 10 August 2023, which among other changes refined the interoperability conditions for passenger coaches and standardised gangway design requirements to facilitate Union-wide vehicle authorisation.
Fire safety across passenger systems
EN 45545-2, the fire protection standard for railway vehicles, applies to all materials and components in the passenger environment. Hazard Level (HL) requirements apply differentially depending on vehicle category and the degree of enclosure: a sealed high-speed train operating through tunnels carries higher hazard level requirements than a suburban multiple unit running in open air.
Gangway bellows, interior panels, seat upholstery, and cable insulation must all demonstrate compliance with the applicable HL classification.
Integration and lifecycle constraints
The subsystems in this section share a structural challenge: they have different service lives from the vehicle bodies that house them.
Passenger information displays and CCTV electronics typically require replacement well before the vehicle body reaches mid-life; door mechanisms are specified for defined operating-cycle lifetimes, after which component replacement is expected; gangway bellows replace on intervals governed by material fatigue and UV exposure.
Vehicle bodies are designed for a 30-to-40-year service life. Managing these mismatched lifecycles requires modular design, accessible mounting arrangements, and technology-agnostic interfaces — particularly for electronics — so that later-generation hardware can be installed without structural modification.
The EU-Rail Joint Undertaking’s work on next-generation TCMS architecture is explicitly oriented toward creating standardised, interoperable onboard networks that can accommodate equipment upgrades without full system replacement.