ISO 24298:2025

International
Standard
ISO 24298
First edition
Intelligent transport systems —
2025-07
Public transport — Light emitting
diode (LED) destination board
system for public transport buses
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 4
5 Requirements and types of LEDDBS . 4
5.1 Rated voltage .4
5.2 Size of LEDDB display area .4
5.3 Types and requirements of LEDDBS controllers .5
5.4 Other requirements for controllers .5
5.5 Performance requirements .5
5.6 Classification of functional status .6
6 Construction . 6
7 Requirements (Tests) of LEDDBS . 6
7.1 General .6
7.2 Classification of tests .6
7.2.1 Type tests .6
7.2.2 Samples .7
7.2.3 Acceptance tests .8
7.3 Visual examination .8
7.4 Dimensions .8
7.5 Functional test .8
7.6 Performance test .8
7.7 Minimum visibility distance test .8
7.8 Flicker test .9
7.9 Colour test .9
7.10 Insulation resistance test .9
7.11 EMI/EMC test .9
7.12 Electrostatic discharge test .9
7.13 Endurance test .10
7.14 Vibration test .10
7.15 High temperature test . . .10
7.16 Cold test .10
7.17 Damp heat test .11
7.18 Ingress Test . .11
7.19 Corrosion resistance test .11
7.20 Tests for wiring harness .11
7.20.1 General .11
7.20.2 Flammability test .11
7.20.3 Electrical properties .11
7.20.4 Flammability of corrugated sleeves .11
7.21 Reverse polarity test .11
7.22 High voltage test .11
7.23 Transient test on controllers . 12
8 Marking . .12
Annex A (normative) Additional functional requirement of LEDDBS .13
Annex B (normative) Test for corrosion resistance .16
Bibliography . 19

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
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This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Light emitting diode (LED) destination board systems are used widely around the world in public
transportation. A study estimated that the global market for real time passenger information system could
[3]
have been valued at $20 billion. Further, access to real-time arrival information on transport systems
decreases the perceived and actual wait times for riders and improves user satisfaction.
Improper and unsystematic display of destination boards on buses causes problems for the commuting
public. Installation of destination boards with an LED display, as covered in this document, will be very
helpful in providing information on route numbers and destinations to the commuting public.
This document covers the constructional and performance requirements of LED destination board systems.

v
International Standard ISO 24298:2025(en)
Intelligent transport systems — Public transport — Light
emitting diode (LED) destination board system for public
transport buses
1 Scope
This document specifies the constructional and performance requirements and methods of tests for light
emitting diode destination board systems (LEDDBSs) for use in all categories of buses and coaches (including
mini/midi buses).
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.
ISO 7637-2, Road vehicles — Electrical disturbances from conduction and coupling — Part 2: Electrical transient
conduction along supply lines only
ISO 9772, Cellular plastics — Determination of horizontal burning characteristics of small specimens subjected
to a small flame
ISO 10605, Road vehicles — Test methods for electrical disturbances from electrostatic discharge
ISO 16750-2, Road vehicles — Environmental conditions and testing for electrical and electronic equipment —
Part 2: Electrical loads
IEC 60529, Degrees of protection provided by enclosures (IP CODE)
IEC 60947-1, Low-voltage switchgear and control gear: Part 1 General rules
ISO 11452-2, Road vehicles — Component test methods for electrical disturbances from narrowband radiated
electromagnetic energy — Part 2: Absorber-lined shielded enclosure
CISPR 25, Vehicles, boats and internal combustion engines — Radio disturbance characteristics — Limits and
methods of measurement for the protection of on-board receivers
JIS C 3406, Low-Voltage cables for Automobiles
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
light emitting diode destination board system
LEDDBS
system consisting of LED display boards along with requisite software and hardware (controller and
associated circuits) used for displaying destinations/route information, etc., on buses

3.2
with synchronized voice
light emitting diode destination board system, with synchronized voice
voice used for announcing the route information with GNSS assisted trigger along with a manual override
3.3
outward facing LEDDBS
outward facing light emitting diode destination board system
display board used to provide information to users present outside the bus
3.4
inward facing LEDDBS
inward facing light emitting diode destination board system
display board used to provide information to users present inside the bus
3.5
bus
large motor vehicle designed to carry passengers usually along a fixed route
3.6
coach
type of bus used for carrying passengers on excursions and on longer distances between cities, or even
between countries
Note 1 to entry: Unlike buses designed for shorter journeys, coaches often have a luggage hold separate from the
passenger cabin and are normally equipped with facilities required for longer trips including comfortable seats and
sometimes a toilet.
3.7
visibility distance
minimum distance at which the text on the display of the light emitting diode destination board (LEDDB)
can be clearly discerned
3.8
area
overall area of the display of light emitting diode destination board, in square millimetres
3.9
LED matrix
array of rows and columns of LEDs in the display area as shown in Figure 1

Key
1 row 1
2 pitch (V)
3 row 9
4 row 16
5 column 1
6 column last
7 display height
8 display width
9 pitch (H)
Figure 1 — LED matrix
3.10
pitch
distance between the centre of pixels, expressed in mm
3.11
ratings
voltage and current range at which the light emitting diode destination board system (LEDDBS) is designed
to operate satisfactorily
3.12
rated voltage
operating voltage specified by the manufacturer for a terminal or pair of terminals at which the LEDDBS is
designed to operate satisfactorily
3.13
type test
test carried out to prove conformity of light emitting diode destination board system (LEDDBS) with respect
to the requirements of this document
Note 1 to entry: Type tests are intended to prove the general quality, design and performance of a given type of LEDDBS.
3.14
acceptance test
test required to be carried out on samples taken from a sampling lot for acceptance of the sampling lot

3.15
sampling lot
fifty light emitting diode destination board systems of the same type, design and rating, which have been
manufactured in the same premises and using the same process and materials, and which are offered for
inspection at one time
3.16
functional status classification
operational status of a device during and after exposure to an electromagnetic environment
4 Abbreviated terms
ISO International Organization for Standardization
ITS Intelligent Transport Systems
LEDDB Light emitting diode destination board
LEDDBS Light emitting diode destination board system
CAN Controller Area Network
GNSS Global navigation satellite system
UV Ultra violet
DTC Diagnostic trouble codes
PID Parameters identifiers
PCB Printed circuit board
RMS Root mean square
5 Requirements and types of LEDDBS
5.1 Rated voltage
The rated voltage shall be either 12 V or 24 V DC and the same rated voltage shall be marked on the LEDDBS.
5.2 Size of LEDDB display area
The minimum size of the outward facing LEDDBS display area shall be as given in Table 1.
Table 1 — Minimum size of outward facing LEDDBS display area
Minimum height Minimum width Rows Columns
S. No. Location
mm mm Min. Min.
1 Front 200 1 800 16 140
2 Front (Mini/Midi) 200 900 16 96
3 Rear 200 900 16 96
4 Service door side 200 900 16 96
The minimum size of the inward facing LEDDBS display area shall be as given in Table 2.

Table 2 — Minimum size of inward facing LEDDBS display area
Minimum height Minimum length Rows Columns
S. No. Location
mm mm Min. Min.
1 Any 100 900 16 112
5.3 Types and requirements of LEDDBS controllers
The controller of the destination board(s) may be any of the following types, subject to agreement between
the purchaser and the supplier:
a) without voice and without GNSS or any other technological agnostic technique to establish location
compatibility;
b) with synchronized voice and display on inward facing LEDDB with in-built GNSS/GNSS or any other
technological agnostic technique to establish location compatible;
c) with synchronized voice and display on inward facing LEDDB with GNSS or any other technological
agnostic technique to establish location compatibility with provision of two-way communication with
control centre via an add-on device; and
d) incorporates all features of the above, i.e. those mentioned in 5.3 a), b) and c).
5.4 Other requirements for controllers
Further to the requirements of 5.3, the controller shall also:
a) be capable of displaying same and different messages on each of the signs (front, rear, side and inner);
b) have a minimum size of memory according to customer specifications;
c) be of an "automotive grade" rated for –25 °C to +85 °C. and PCB’s shall be conformal coated;
The controller display shall:
d) be alphanumeric with a keypad having minimum four keys;
e) have the route programming files uploaded;
f) Include a route selection function; and
g) be capable of displaying all driver-related route information intended to appear on its display.
5.5 Performance requirements
5.5.1 The display shall be alphanumeric with graphic capability in English and/or other local languages
and shall be visible in fixed, scrolling and flashing mode with fixed route number according to customer
requirements.
5.5.2 Signs shall have the capability to retain the last message displayed in the memory of the sign even
in the event of power failure and without the message being reloaded from the controller. A test shall be
performed by disconnecting the controller from the sign and power to the sign will be switched ‘OFF’ and
‘ON’ to see if the last message is retained and displayed.
5.5.3 The LEDDBS shall have a programming capability for a minimum number of routes according to
customer requirements.
5.5.4 The additional functional requirements of LEDDBS provided in Annex A shall apply.
...