ISO 23599:2019

INTERNATIONAL ISO
STANDARD 23599
Second edition
2019-01
Assistive products for blind and
vision-impaired persons — Tactile
walking surface indicators
Produits d'assistance pour personnes aveugles ou visuellement
affaiblies — Indicateurs tactiles de surfaces de marche
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General provisions. 3
4.1 General principles . 3
4.2 Detecting and distinguishing TWSIs . 4
4.2.1 General. 4
4.2.2 Tactile contrast . 4
4.2.3 Visual contrast . 4
4.2.4 Design for prevention of tripping . 4
5 Requirements and recommendations. 4
5.1 Specifications for shape and dimensions of TWSIs . 4
5.1.1 General. 4
5.1.2 Attention patterns . 5
5.1.3 Guiding patterns . . 6
5.2 Surrounding or adjacent surfaces .10
5.3 Visual contrast .10
5.3.1 General.10
5.3.2 Luminance contrast .10
5.3.3 Calculation of the luminance contrast value .11
5.3.4 Maintenance of minimum luminance contrast .11
5.3.5 Measurement condition .11
5.3.6 Difference in colour or tone .11
5.3.7 Illumination .11
5.4 Materials .11
5.5 Installation .12
5.5.1 General.12
5.5.2 Principles for installation of TWSIs .12
5.5.3 Principles for installation of attention patterns .12
5.5.4 Principles for installation of guiding patterns .13
Annex A (informative) Luminance contrast .14
Annex B (informative) Examples of installations of TWSIs in specific situations .17
Bibliography .38
Foreword
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This document was prepared by Technical Committee ISO/TC 173 Assistive products.
This second edition cancels and replaces the first edition (ISO 23599:2012), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— Correction of Weber’s formula in Table A.1;
— Correction of Reference [18] in the Bibliography.
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 © ISO 2019 – All rights reserved

Introduction
The purpose of this document is to create requirements for Tactile Walking Surface Indicators (TWSIs)
for blind or vision-impaired persons.
When blind or vision-impaired persons travel alone, they might encounter problems and hazards in
various situations. In order to obtain information for wayfinding, these pedestrians use information
available from the natural and built environment, including tactual, acoustic and visual information.
However, environmental information is not always reliable and it is for this reason that TWSIs perceived
through use of a long white cane, through the soles of shoes and through the use of residual vision have
been developed.
TWSIs were invented in Japan in 1965. They are now used around the world to help blind or vision-
impaired persons travel independently. At present, TWSI patterns and installation methods vary from
country to country. This document aims to provide a basis for a common approach for TWSIs at the
international level, while acknowledging that some differences might be necessary at the local level to
accommodate climatic, geographical, cultural or other issues that might exist.
TWSIs should be designed and installed based on a simple, logical and consistent layout. This will
enable tactile indicators to facilitate not only the independent travel of blind or vision-impaired persons
in places they frequently travel, but also to support their independent travel in places they visit for the
first time.
Currently, there are several forms of TWSIs, but the ability to detect differences in tactile patterns
through the soles of the shoes or the long white cane varies depending on individual differences.
Therefore, the consolidated findings of science, technology and experience were employed to define the
characteristics of TWSIs that can be detected and recognized by potential users. Additionally, in order
to ensure that TWSIs achieve maximum effect in conveying information, it is important that they be
installed in or on a smooth surface where blind or vision-impaired persons can identify them without
interference from an irregular walking surface.
It is also necessary to ensure that TWSIs can be effectively used by vision-impaired persons as well as
people who are blind. For this purpose, TWSIs should be easily detectable through use of residual vision.
This is achieved through visual contrast between TWSIs and the surrounding or adjacent surface.
Visual contrast is influenced primarily by luminance contrast, and secondarily by difference in colour
or tone. In order to have good visibility, it is necessary to have sufficient illumination without glare and
it is important to maintain the visual contrast between TWSIs and the surrounding or adjacent surface.
While TWSIs should be effective for blind or vision-impaired persons, attention should also be paid
to their surface structure and materials in order to ensure that all pedestrians, including those with
impaired mobility, can safely and effectively negotiate them.
TWSIs are installed in public facilities, buildings used by many people, railway stations and on sidewalks
and other walking surfaces. Attention patterns may be installed in the vicinity of pedestrian crossings,
at-grade kerbs, railway platforms, stairs, ramps, escalators, travelators, elevators, etc. Guiding patterns
may be used alone or in combination with attention patterns in order to indicate the walking route
from one place to another.
INTERNATIONAL STANDARD ISO 23599:2019(E)
Assistive products for blind and vision-impaired
persons — Tactile walking surface indicators
1 Scope
This document provides product specifications for tactile walking surface indicators (TWSIs) and
recommendations for their installation in order to assist in the safe and independent mobility of blind
or vision-impaired persons.
This document specifies two types of TWSIs: attention patterns and guiding patterns. Both types can
be used indoors and outdoors throughout the built environment where there are insufficient cues for
wayfinding, or at specific hazards.
NOTE Some countries have adopted other designs of TWSIs based on the consolidated findings of science,
technology and experience, ensuring that they can be detected and distinguished by most users.
This document is not intended to replace requirements and recommendations contained in such
national standards, regulations or guidelines.
2 Normative references
There are no normative references in this document.
3 Terms and d
...