Persons with Reduced Mobility National Technical Specification Notice (PRM NTSN)
Supporting multimodal passenger information on the railway
What this is
The PRM NTSN (Persons with Reduced Mobility National Technical Specification Notice, sometimes now referred to as the Accessibility NTSN) is a UK rail technical standard, published by the Secretary of State for Transport under regulation 3B of the Railways (Interoperability) Regulations 2011. It is the UK's post-Brexit mirror of the EU's PRM TSI, Commission Regulation (EU) No 1300/2014, setting binding technical specifications for the accessibility of railway infrastructure and rolling stock. DfT's Code of Practice for accessible stations (see the separate datasheet) is intended to be read alongside it.
Who it applies to
Infrastructure managers, station operators and train operating companies for main-line passenger rail (light rail and trams are excluded). It applies to relevant new, upgraded or renewed infrastructure and rolling stock subsystems.
What kind of instrument this is
A binding national technical standard, issued under statutory authority (regulation 3B of the Railways (Interoperability) Regulations 2011) — not voluntary guidance.
Specific requirements relevant to announcements and accessible communication
- 4.2.1.10 Visual information (infrastructure) — signposting, pictograms, printed or dynamic information; must include safety information/instructions and train departure information; text must be easily readable with contrasting fonts and symbols.
- 4.2.1.11 Spoken information (infrastructure) — audible station announcements must meet a minimum public-address intelligibility standard, measured as STI-PA (Speech Transmission Index for Public Address). We recommend checking the exact current figure(s) in the in-force NTSN Accessibility document directly before quoting a specific number, as intelligibility requirements can be expressed as more than one threshold (e.g. an average plus a minimum-at-most-locations figure).
- 4.2.2.7 Customer information (rolling stock) — safety information, route information including delays and unplanned stops, on-board facility locations, with contrast and readable typeface requirements.
- 4.2.2.7.3 Dynamic visual information (rolling stock) — destination/route displays; next-stop information must be readable from at least 51% of passenger seats.
- 4.2.2.7.4 Dynamic audible information (rolling stock) — the next stop must be announced with a minimum lead time before arrival (at least two minutes' notice).
What organisations are expected to do
- Provide both visual (4.2.1.10 / 4.2.2.7.3) and spoken (4.2.1.11 / 4.2.2.7.4) passenger information at stations and on rolling stock.
- Ensure audible announcements meet the STI-PA intelligibility threshold set out in the current NTSN.
- Ensure visual displays are readable from the specified proportion of seats, and that information is consistent across both formats.
Which requirements AnnounceAgain can help address
The underlying principle running through 4.2.1.10/4.2.1.11 and 4.2.2.7.3/4.2.2.7.4 — that spoken information must have a visual counterpart — is directly what AnnounceAgain is built to support, in the same way as the DfT station Code of Practice's Section L1 (see that datasheet).
How AnnounceAgain addresses them
- Automatically transcribes station and on-board PA announcements into text, giving passengers a visual counterpart to spoken information, without requiring the underlying PA hardware to change.
- Provides translation, extending accessible information beyond what the NTSN itself mandates.
- Gives passengers on their own device a supplementary channel alongside the fixed dynamic display, useful where seat position, crowding or sightlines limit visibility of the fitted display — this does not substitute for the fitted display requirement itself (see section 8).
Requirements AnnounceAgain does not satisfy by itself
- Does not measure, certify or guarantee the STI-PA intelligibility standard of the underlying PA hardware (4.2.1.11) — that is a property of the physical PA system's design and acoustic environment.
- Does not provide the fitted dynamic visual display required under 4.2.1.10 / 4.2.2.7.3, including the “readable from 51% of seats” requirement, and is a supplementary personal-device channel rather than a substitute for it.
- Does not address platform/train interface, boarding assistance, or the many other PRM NTSN requirements unrelated to information provision.
Requirements needing certified hardware or other measures
- The physical PA system itself and its STI-PA intelligibility certification (4.2.1.11).
- The fitted dynamic visual display units on platforms and rolling stock, including sightline compliance (4.2.1.10, 4.2.2.7.3).
- Boarding ramps, accessible toilets, the platform–train interface, and the many other PRM NTSN requirements outside passenger information.