prEN 17420

SLOVENSKI STANDARD
01-julij-2025
Železniške naprave - Sprednja konstrukcija tramvajskih vozil ob upoštevanju
varnosti pešcev
Railway applications - Vehicle front design for trams with respect to pedestrian safety
Bahnanwendungen - Fahrzeugkopfgestaltung von Straßenbahn-/Tramfahrzeugen im
Hinblick auf den Passantenschutz
Applications ferroviaires - Conception de l’extrémité des véhicules de tram en ce qui
concerne la sécurité des piétons
Ta slovenski standard je istoveten z: prEN 17420
ICS:
13.200 Preprečevanje nesreč in Accident and disaster control
katastrof
45.140 Oprema za podzemne vlake, Metro, tram and light rail
tramvaje in lahka tirna vozila equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2025
ICS 13.200 Will supersede CEN/TR 17420:2020
English Version
Railway applications - Vehicle front design for trams with
respect to pedestrian safety
Applications ferroviaires - Conception de l'extrémité Bahnanwendungen - Fahrzeugkopfgestaltung von
des véhicules de tram en ce qui concerne la sécurité Straßenbahn-/Tramfahrzeugen im Hinblick auf den
des piétons Passantenschutz
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 256.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17420:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Symbols and abbreviations . 7
5 Front design of tram vehicles . 7
5.1 Objective / concept . 7
5.2 Sequence of an impact . 7
5.3 Reference collision scenarios . 7
6 Reference collision scenario type A. 8
6.1 Introduction . 8
6.2 Front surface . 8
6.2.1 General . 8
6.2.2 Impact surface . 8
6.2.3 Extended impact surface . 8
6.3 Geometric criteria to reduce the severity of injuries . 9
6.3.1 General . 9
6.3.2 Objective of the desired kinematics . 9
6.3.3 Evaluation points . 9
6.3.4 Geometric parameters . 10
6.3.5 Evaluation criteria for impact surface and extended impact surface . 13
6.3.6 Recommendation for evaluation procedure . 14
6.3.7 Vehicle front geometry . 14
6.3.8 Summary of requirements to minimize the severity of pedestrian injuries . 15
6.4 Numerical simulation of pedestrian impact scenario type A . 16
6.4.1 Introduction . 16
6.4.2 Modelling hypotheses for a pedestrian – tram vehicle collision. 19
6.4.3 Specification for the numerical analysis . 19
6.4.4 Criteria . 22
7 Reference collision scenario type B. 24
7.1 Introduction . 24
7.2 Objectives . 24
7.3 Assessment . 25
7.4 Validation program . 25
7.4.1 Test objectives . 25
7.4.2 Test conditions . 25
7.4.3 Run over tests . 26
7.4.4 Criteria . 29
7.4.5 Documents to be provided . 29
Annex A (informative) PACM test protocol report . 30
Bibliography . 35
European foreword
This document (prEN 17420:2025) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede CEN/TR 17420:2020.
1 Scope
This document is applicable to tram vehicles in accordance with EN 17343. Tram-Train vehicles, on track
machines, infrastructure inspection vehicles and road-rail machines in accordance with EN 17343 and
demountable machines/machinery are not in the scope of this document.
This document describes passive safety measures to reduce the consequences of collisions with
pedestrians. These measures provide the last means of protection when all other possibilities of
preventing an accident have failed, i.e.
— design provisions for the vehicle front to minimize the impact effect on a pedestrian when hit,
— design provisions for the vehicle front for side (lateral) deflections in order to minimize the risk of
being drawn under the vehicle on flat ground (embedded track),
— design provisions for the vehicle body underframe to not aggravate injuries to a pedestrian/body
lying on the ground,
— provisions to prevent the pedestrian from being over-run by the leading wheels of the vehicle.
This document focuses on the consequences of the primary and tertiary impact. The consequences of a
secondary impact are out of the scope of this document.
The following measures to actively improve safety are not in the scope of this document:
— colour of front;
— additional position lights;
— additional cameras;
— driver assistance systems;
— additional acoustic warning devices, etc.;
— view of the driver / mirrors;
— consequences for pedestrian injuries due to secondary impact with infrastructure (side posts,
concrete ground, poles, trees, etc.).
The provisions of this document only apply to new vehicles.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 15663:2017+A2:2024, Railway applications – Vehicle reference masses
EN 17343:2023, Railway applications – General terms and definitions
3 Terms and definitions
For the purposes of this document, the following terms and definitions given in EN 17343:2023 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
tram vehicle
urban rail vehicle designed to run on a tram network
[SOURCE: EN 17343:2023, 3.1.7.1.2.2]
3.2
collision scenario
collision scenario derived from accident analysis that is applicable for design and assessment
3.3
head injury criterion
HIC
measure of the likelihood of head injury stemming from impact or acceleration
Note 1 to entry: The HIC is calculated using the following formula:
25,
t

∫
dt
a
t R
HIC t− t

( )
15 2 1
tt−
( )
2 1


where
t represents the start of the time interval,
t2 represents the end of the time interval,
HIC is the maximum value of HIC for (t – t ) ≤ 15 ms,
2 1
a is the resultant acceleration
R
2 22
a = a ++aa
R X YZ
where
a , a and a represent the accelerations in g in X, Y and Z directions.
X Y Z
Note 2 to entry: The 15 ms time frame relates to the original biomechanical testing used to establish the HIC as
an injury criterion commonly accepted for impacts against fixed surfaces.
Note 3 to entry: This criterion can be used to assess the safety regarding vehicles, personal protective gear and
sports equipment.
=
3.5
tram system
urban rail system operated on infrastructure shared with road traffic and/or its own infrastructure
Note 1 to entry: The tram system comprises the tram network, related rolling stock, and the associated operation.
Note 2 to entry: Sections of the route can be signal controlled.
Note 3 to entry: A tram network can be linked to other rail networks.
Note 4 to entry: For tram systems having sections segregated from road traffic the term light rail system (LRS) is
used.
Note 5 to entry: Road traffic includes road users like cars, pedestrians, cyclists, wheelchair users, etc.
[SOURCE: EN 17343:2023, 3.1.4.2]
3.6
rescue mannequin
life size model of a person used in tests to simulate what happens to people when a vehicle gets into an
accident (with a pedestrian)
3.7
anthropomorphic test d
...