Guidebook for the Proper Installation of Tactile
Ground Surface Indicators (Braille Blocks):
Common Installation Errors

International Association of Traffic and Safety Sciences
April / 2008

Publisher
TOKUDA Katsumi ・ MIZUNO Tomomi・ NISHIDATE Arisa・
ARAI Kunijiro・ AOYAGI Mayumi
International Association of Traffic and Safety Sciences
6-20, 2-chome, Yaesu, Chuo-ku, Tokyo,104-0028,Japan
Tel： +81-3-3273-7884； Fax： +81-3-3272-7054
E-mail： mail@iatss.or.jp； URL. http://www.iatss.or.jp
Copyright@2008 by International Association of
Traffic and Safety Sciences, April, 2008
Printed in Japan

Introduction

This guidebook is based on the findings of a long -term International Association of Traffic and
Safety Sciences (IATSS) researc h project including field studies, experiments, interviews withthe visually impaired and written surveys of wheelchair users, stroller users, the elderly andparents of small children. We fervently hope that in the hands of those involved with Tactile
ground surface indicators around the world this guidebook will enable the installation, underconsistent rules, of Tactile ground surface indicators that are effective in helping people with
impaired vision without creating obstacles for other pedestrians. Pl ease direct questions about thecontent of this guidebook or requests for additional materials to the IATSS address below.

2008. April

TOKUDA Katsumi， University of Tsukuba
MIZUNO Tomomi， Kinki University
NISHIDATE Arisa， University of Toyama
ARAI Kunijiro， University of Tsukuba
AOYAGI Mayumi， Seitoku University

International Association of Traffic and Safety Sciences
Address：6-20, 2-chome, Yaesu, Chuo-ku, Tokyo,
104-0028,JAPAN
Tel：+81-3-3273-7884
Fax：+81-3-3272-7054
E-mail：mail@iatss.or.jp

Contents

1. Guidebook Objectives

1

2. Characteristics of and Issues with Tactile Ground Surface Indi cators in Europe,
America, Oceania and Asia

1(1) Installations in Each Country and Their Characteristics

1

1) Europe22) The Americas

63) Oceania

74) Asia8(2) Installation Errors Similar to Those in Japan111） Failure to Install Warning Blocks Before Crosswalks and Stairways

112） Narrow Warning Blocks

113）Incorrectly Located Blocks

124） Failure to Install Warning Blocks Where Directional Blocks Intersect125） Obstacles Above or Near (Within 30cm of) tactile ground surface indicators

126）Excessive Number of Blocks

137）Interruption by Objects such as Manhole Covers

138） Warning Blocks in Places Where They are Unnecessary139） Warning Blocks Where Directional Blocks Should be Installed

1410）Installations at Medians1411）Installations that Impede Wheelchair Users

14

3. Braille Block Installation Methods

15(1) Braille Block Installation Methods

151) Directional Blocks

162) Warning Blocks

16(2) Common Installation Er rors and How to Remedy Them

161) Manhole Covers

172) Interrupted Tactile ground surface indicators

173) Jurisdictional Variations in Block Size, Shape or Color

184）Warning Blocks Where Lines of Directional Blocks Bend195) Unnecessary Warning Blocks Amid Directional Blocks

206) Small Blocks

217) Block Routes

238) Crosswalks

259) Intersections

30

10) Stairs

3111) Before Escalators

3412) Errors at Platforms

3513) Before Gates and Doors

3514) Slopes

3615) Elevators

3716) Station Wickets

3817) Disabled Parking Spaces

3918) Post-Construction Problems

4019) Poor Maintenance4120) Obstacles Positioned Over Tactile ground surface indicators

4221) Use for Other Purposes

44

1. Guidebook Objectives

This guidebook seeks to achieve the following objectives:
1） To introduce characteristics of and issues with Tactile ground surface indicators in Europe,
America, Oceania and Asia.
2） To indicate specific criteria for promoting consistent installation around the world, which isessential to ensuring that Tactile ground surface indicators function effectively for people with
impaired vision.
3） To provide materials that identify specific examples of installations that confuse people with
impaired vision and that can be used to improve existing improper installations.

2．Characteristics of and Issues with Tactile Ground Surface Indicators in Europe, America,
Oceania and Asia

(1) Installations in Each Country and Their Characteristics
Tactile ground surface indicators facilitate the safe movement of people with impair ed vision.
Since being devised in Japan in 1965 they have spread to other nations around the world. Because
the visually impaired can use them with almost no modification to their normal way of walking,and because the cost of installation is low, tactile ground surface indicators are believed to be themost effective system for guiding people with impaired vision. In Japan, tactile ground surface
indicators are installed in accordance with local ordinances based on the Ministry of Land,
Infrastructure, Transport and Tourism's Guidelines for Installation of Tactile ground surface
indicators for the Visually Impaired and Commentary.
There are two types of tactile ground surface indicators: warning blocks that indicate thelocation of hazards or destination f acilities (Fig. 1) and directional blocks that indicate directionof travel (Fig 2). Standards are inconsistent overseas, with some countries using rules and blocks
similar to those in Japan and others using their own rules and country -specific blocks.
Tactile ground surface indicators are designed to enable people with impaired vision to identify
their own position, hazardous locations and the direction in which to walk. They must, therefore,
be installed in safe locations in a consistent manner that facil itates identification by the visually
impaired through contact with the feet. Nevertheless, numerous installations in Japan are
dangerous, superfluous or create an obstacle for wheelchair users and others. Such situations are
increasing overseas, as well. Although Japan exports tactile ground surface indicators, it has notadequately communicated to foreign countries the appropriate methods of installation andoperation. As a consequence, people with impaired vision in many countries find it difficult towalk using tactile ground surface indicators as a guide, resulting in both accidents and confusion.

Fig. 1: Warning Block

Fig. 2: Directional Block

1) Europe① London, UK
Tactile ground surface indicators are installed at many locations throu ghout the city, near
historical buildings like Big Ben, Buckingham Palace and the British Museum as well as indowntown and residential areas. Tactile ground surface indicators are installed in accordancewith unique standards established by the United Kin gdom's Department for Transport. Blocks
with dots and blocks with bars are used, but both types are intended as warning blocks; neither
serves a directional function.
Blocks are mainly installed before crosswalks, at medians, at station platforms and at th e top
and bottom of stairways. Blocks with dots are for installations at crosswalks, medians and station
platforms while blocks with bars are for installations at stairways. The color of blocks installed
before crosswalks is also supposed to vary with cros swalk type: red blocks are to be used before
zebra crossings (where pedestrians always have the right of way), pelican crossings (equippedwith push-button traffic lights) and puffin crossings (with sensor -equipped push button traffic
lights) while other colors (yellow, grey, etc.) are to be used at other crosswalks where
automobiles have the right of way. The difference in color is intended to assist people with low
vision navigate the crosswalk safely, but many locations do not conform to the established colors.
Different color blocks are also sometimes installed when repairs are made. Blocks are installed in
an L-shaped configuration at crosswalks with push -button traffic signals, with the corner of the Lmarking the location of the push button (Fig. 3).
Blocks with bars are installed at the top and bottom of stairways such that the direction of thebars is parallel to the long dimension of the treads (Fig. 4).

Fig. 3: L-Shaped Tactile ground surface
indicator Installation (London, UK)

Fig. 4: Blocks

with

Bars

Markingthe

Bottom of a Stairway (London, UK)② Paris, France
In Paris, warning blocks are installed before crosswalks, at th e top and bottom of stairs leadingin and out of subway stations and on subway and train platforms. In some areas, blocks serving a
directional function are installed within crosswalks (Fig. 5). Most blocks are white but black,grey and pale yellow are also used. To protect the scenery, subway station signs and otherprominent manmade objects are not installed near historical sites such as the Arc de Triomphe,
the Paris National Opera, the Louvre or the Place de la Concorde but tactile ground surface
indicators, in colors that stand out (white and yellow), are an exception (Fig. 6)
Paris has recently been emphasizing barrier -free accessibility, including such experimental
efforts as the uniquely configured blocks installed at the Montparnasse rail station (F ig. 7).

Fig. 5: Directional Blocks within a
Crosswalk (Paris, France)

Fig. 6: Tactile Ground Surface Indicatorsnear the Arc de Triomphe (Paris,
France)Fig. 7: Tactile Ground Surface Indicators at
Montparnasse Station (Paris, France)③ Frankfurt, Germany
In Frankfurt, blocks are installed inside rail and subway stations and on the platforms at rail,
subway and tram stations. Many blocks are white, although some are grey. The warning blocks
inside rail stations are of similar configurati on to those used in Japan. The directional blocks
used at train stations and the blocks used at subway and tram stations are uniquely German in
configuration. Directional blocks at train stations are made up of thin linear protrusions (Fig. 8).
Directional blocks are installed at rail station platforms but no warning blocks —only non-slip
strips with small dot-shaped protrusions located at the edge of the platform. Tram stations use thesame directional blocks as at rail stations but warning blocks are never used at platform edges orwhere blocks intersect (Fig. 9).

Fig. 8: Directional Blocks Used at Rail
Stations (Frankfurt, Germany)

Fig. 9: Tactile Ground Surface Indicators at
Tram Station (Frankfurt, Germany)④ Brussels, Belgium
In Brussels, blocks are installed before crosswalks, at bus stops and at subway and rail stations andplatforms. Most blocks are grey, with yellow, silver and bl ack blocks also used. Brussels has a mix oflocations where the blocks (warning and directional) and installation methods are similar to those inJapan and locations where block configuration and installation methods are unique to Belgium .

One of the Belgium-specific blocks uses metal disks of roughly 85mm in diameter and 8mm inheight (Fig. 10). In Japan, the prescribed size of warning block protrusions is 22mm in diameter(±1.5mm) and 5mm in height, a size designed to promote mobility by the visually impa iredwithout impeding the movement of wheelchair users or elderly pedestrians. Given the large size,height and slipperiness of the metal disks used in the Belgian blocks, one suspects that theypresent a significant obstacle for wheelchair users, children and the elderly.
In one part of the city, metal bars are embedded in the road surface where one would expect tofind warning blocks (at the top of stairs and escalators, for example) (Fig. 11). Being only 3mm
in height, these protrusions create no obstacl e for wheelchair users or elderly pedestrians but also
seem likely to go unnoticed by the visually impaired. In some places, similar metal bars areembedded in the road surface and serve a directional function (Fig. 12). Rubber warning blocks
are also sometimes installed at bus stops where directional blocks intersect (Fig. 13).
Brussels, therefore, presents a mix of block types and installation styles that may create
confusion for people with impaired vision.

Fig. 10: Metal Disks Used in Belgium(Brussels, Belgium)

Fig. 12: Embedded Directional Metal Bars
(Brussels, Belgium)

Fig. 11: Embedded Metal Bars Marking the
Top of a Stairway (Brussels, Belgium)

Fig. 13: Rubber

Warning

BlocksDirectional Blocks Intersect(Brussels, Belgium)Where⑤ Amsterdam, Netherlands
In Amsterdam, blocks are installed before crosswalks, at medians and on tram and subway
platforms. Both warning blocks and directional blocks are installed according to the same rules as
in Japan. Netherlands-specific blocks are used in addition to blocks configured like those inJapan. Most directional blocks are white or grey while warning blocks are yellow or grey. Where
directional and warning blocks are used together the color of the blocks is often not uniform.
Netherlands-specific blocks include some with thin recessed lines as in Fig. 14. With very little
surface irregularity, such blocks are extremely difficult to detect with the feet or a white cane.
Grooves carved into the pavement at subway station platforms (Fig. 15) are also difficult forpeople with impaired vision to recognize.

Fig. 14: Netherlands-Style Warning Blocks

Fig. 15: Grooves Carved into the(Amsterdam, Netherlands)

Pavement(Amsterdam,

2) The Americas

Netherlands)① USA (San Francisco, Los Angeles and San Diego, California)
California uses distinctive landmarks to help the visually impaired cross the road safely (Fig.
16). Rather than lay down tactile ground surface indicators before crosswalks, shallow grooves
are cut into the pavement. These are more difficult to detect than tactile ground surface indicators
when using feet or a cane. This installation method is uniform in S an Francisco, Los Angeles andSan Diego.
Although the number of locations is not large, warning blocks like those in Japan are also used
before crosswalks, at rail and subway stations and at tram platforms. Directional blocks are also
installed at rail station platforms. Blocks are yellow, black or white. Installations of blocks
before crosswalks (Fig. 17) appear arbitrary, lacking consistent rules.
At rail station platforms, directional blocks are installed near train doors (Fig. 18). However,
only one or two blocks (30–60cm) are installed as landmarks at each location; they do not serve
to direct people toward stairways or ticket gates.

Fig.16: Shallow Grooves Cut

into theFig. 17: Tactile Ground Surface Indicators

Pavement before a Crosswalk (Sanbefore a Crosswalk (San Francisco,Francisco, USA)

USA)

Fig. 18: Tactile Ground Surface Indi cators
at a Rail Station Platform(San Francisco, USA)

② Tijuana, Mexico
Tijuana uses landmark installations before crosswalks that are similar to those used in
California. There are, however, no installations of tactile ground surface indicators.

3) Oceania① Sydney, Australia
In Sydney, blocks are installed at rail, monorail and light rail station platforms, before exterior
stairways, before exterior obstacles, at airports and at bus stops. Warning blocks and directional
blocks are similar to those used in Japan, and installed in the sa me way, including at the Opera
House and other well-known tourist spots. Unlike many other countries, however, blocks are notinstalled before crosswalks. As some rail, monorail and light rail stations, directional blocks leadfrom at or near the ticket gates to the platform. Blocks are yellow, silver, blue, green and grey.
Blue blocks are frequently used at rail stations while yellow is often used at monorail and lightrail stations.

② Auckland, New Zealand
In Auckland, warning blocks are installed before crosswalks in the city center, at rails stations
and platforms and before interior stairways at shopping centers and other large -scale facilities. In
suburban areas, directional blocks and warning blocks are installed before crosswalks to create a
T-shaped configuration of about 1–1.5m. In addition, directional and warning blocks are also
installed in areas with facilities for people with disabilities. Such blocks are installed in the samemanner as in Japan. Blocks are most often yellow, with silver and wh ite also used.

4) Asia① Seoul, Busan and Daegu, Korea
In Korea, warning blocks and directional blocks are installed in accordance with Japanese rules
in many locations including sidewalks, subway and rail stations and platforms, public facilities
and large shopping centers. The configuration of the blocks, with the exception of some subway
stations in Seoul (Fig. 19), is the same. Blocks are yellow, silver, brown, white and grey. Because
installation methods are adopted whole cloth from Japan, many of the same errors are found.

Fig. 19: Blocks Used in Some Seoul Subway
Stations (Seoul, Korea)② Beijing, Shanghai, Dalian and Guangzhou, China
Tactile ground surface indicators are installed broadly in major cities such as Beijing, Shanghai,
Dalian and Guangzhou. They can also be found winding through suburban areas surrounding
major cities; the volume of blocks installed is second only to Japan. Both warning and directional
blocks are used, and installed in a manner roughly the same as in Japan. Some areas have theirown rules, however, such as in parts of Guangzhou where no blocks are installed whe redirectional blocks intersect, a location where warning blocks would normally be installed (Fig.
20). Block colors include yellow, grey, green, brown and beige. As in Korea, because installation
methods are adopted whole cloth from Japan, many of the sam e errors are found. Maintenance isalso inconsistent; here and there one sees broken blocks that have been left unrepaired.

③ Taipei and Taichung, Taiwan
As in Korea and China, in Taiwan warning blocks and directional blocks are installed inaccordance with rules nearly identical to those in Japan. Most blocks are yellow, with grey blocks
also in use. Tactile ground surface indicators are frequently installed across the entire sloped arealeading to a crosswalk (Fig. 21), creating an obstacle for wheelchair users and others. In addition,although there are many stepped areas on sidewalks in the city center, very few are marked withwarning blocks. This is dangerous for people with impaired vision and fails to accommodate theirneeds.

④ Hong Kong
In Hong Kong, warning and directional blocks are found at and around rail stations and warning
blocks are installed before crosswalks and at medians in the city center. Blocks are yellow, silver,
black, grey, green and brown. Installation method s are roughly the same as in Japan.

⑤ Singapore
In Singapore, warning and directional blocks are installed primarily around subway stations.
Installation rules are roughly the same as in Japan. Only a very few crosswalks in urban areas areequipped with warning blocks. Blocks are silver, yellow and grey.

⑥ Kuala Lumpur, Malaysia
In Kuala Lumpur, blocks are installed mainly at rail, subway, LRT and monorail stations and thesurrounding sidewalks. In some locations warning and directional blocks are installed as in Japan
while in other locations directional indicators are carved into the pavement and warning blocks
are installed where directional markers intersect and where pedestrians are to stop (Fig. 22). The
latter practice is often followed at rail and LR T stations but the two types were found to coexist
at one location. Blocks are yellow, silver and grey.

⑦ Jakarta, Indonesia
Warning blocks indicating the entrance to parking lots are installed on the sidewalks in Jakarta's
Jalan Thamrin business area as shown in Fig. 23, an installation method unique to Indonesia.
Blocks of this type are installed at nearly every parking lot entrance, making for a great many
installations. Warning blocks are also installed before some crosswalks in the Jalan Thamrin area.
No blocks are installed outside this area, however. Blocks are yellow in color.

⑧ Bangkok, Thailand
Warning and directional blocks are used on many sidewalks in central Bangkok. Warning blocks
are also installed at the top and bottom of stairways at subway and monorail stations. Blocks are
not, however, installed at rail stations or rail platforms. Installat ion rules are roughly the same asin Japan. Blocks are yellow or grey. Many damaged blocks seem to be left unrepaired. Bangkok isa city with many vendors who set up shop on sidewalks; these frequently end up covering theblocks (Fig. 24).

Fig. 20: No Blocks Used Where Directional

Fig. 21: Blocks Installed Across the Sloped

Blocks Intersect (Guangzhou, China)

Area before a Crosswalk (Taipei,
Taiwan)Fig. 22: Directional Indicators Carved IntothePavement

Malaysia)(KualaLumpur,Fig. 23: Tactile Ground Surface

Indicators

Used to Indicate Parking Lot Entrances(Jakarta, Indonesia)

Fig. 24: Sidewalk Vendors Covering Blocks(Bangkok, Thailand)(2) Installation Errors Similar to Those in Japan
As mentioned above, many countries install their blocks following installation methods used inJapan, and "import" the same sort of installation errors seen in Japan. Below we discuss examplesof blocks installed overseas that exhibit such errors.

1） Failure to Install Warning Blocks Before Crosswalks and Stairways
Examples of warning blocks not being installed before crosswalks or stairways despite thedirectional blocks leading to such spots were observed in New Zealand, Korea, China andTaiwan.

2） Narrow Warning Blocks
Examples of narrow warning blocks were observed in the UK, Australia, Korea and Taiwan.
Such installations at station platforms, as in Fig. 25, can lead a person with impaired vision tofall onto the track.

Fig. 25: Use of Narrow (15cm Wide) Warning
Blocks (Sydney, Australia)

3） Incorrectly Located Blocks
Incorrectly located blocks include warning blocks positioned too far from obstacles, thosepositioned too close to obstacles, failing to indicate the start or end of a stairway and incorrect
positioning of blocks at the entrance to crosswalks or doors.
Examples of warning blocks positioned too far from obstacles were observed in the USA,
Australia, Korea, Taiwan and Hong Kong. Examples of blocks positioned too close to obstacles
were found in Korea and China. Examples of incorrect positioning of blocks at the entrance tocrosswalks or doors were found in France, the USA, Australia, Korea and Taiwan (Fig. 26). Sucherrors are the result of failing, when modifying the location of a crosswalk, to change the locationof the blocks, instead leaving them where they were.

4） Failure to Install Warning Blocks Where Directional Blocks Intersect
Examples of failing to install warning blocks where directional blocks intersect, as in Fig. 27,
were observed in Korea, China, Taiwan, Malaysia and Thailand. Such installations can lead a
person with impaired vision to become lost by preventing detection of a turning point5） Obstacles Above or Near (Within 30cm of) tactile ground surface indicators
Examples of obstacles above or near directional blocks (other than items such as bicycl es or
motorcycles that can be moved) were observed in Germany, Korea, China, Malaysia and Thailand.
Because objects located above waist level cannot be detected with a white cane6, in a situation
like the one illustrated in Fig. 2 8 a person with impaired vision could fail to notice the pedestrian
bridge and crash into it, suffering serious injury.

Fig. 26: Incorrect Positioning at the Entrance toa Crosswalk (Paris, France)

Fig. 27: Failure to Install Warning Blocks
Where Directional Blocks Intersect(Taipei, Taiwan)

6） Excessive Number of Blocks
Examples of installations with an excessive number of blocks were observed in the UK, Korea,
Taiwan, Singapore, Malaysia and Thailand. Installations before crosswalks lik e the one
illustrated in Fig. 29 not only obscure the entr ance to the crosswalk but also make it difficult to
identify the direction of the crosswalk, leading to the danger that a person with impaired vision
might step out in the wrong direction, perhaps toward the middle of the intersection. Suchinstallations create obstacles not only for the visually impaired but also for the elderly and for
those using wheelchairs or strollers.

7） Interruption by Objects such as Manhole Covers
Examples of blocks interrupted by objects such as manhole covers (Fig. 3 0) were observed in all
countries that installed blocks except the USA and Singapore, where there are few block
installations and no suc h examples could be found during the current survey. Interrupted blocks
mean confusion for people with impaired vision, who lose their directional guide. There is a needto communicate to the world the importance of installing blocks even on manhole covers .

8） Warning Blocks in Places Where They are Unnecessary
Examples of warning blocks installed in places where they are unnecessary were found in Korea,
China, Taiwan and Hong Kong. As in Fig. 31, warning blocks were frequently installed insituations where there was a slight change in the direction of directional blocks. Warning blocks
cause people with impaired vision to stop and attempt to identify what danger their attention is
being drawn toward. Unnecessary warning blocks greatly reduce walking efficiency.

Fig. 28: Pedestrian Bridge Located above

Fig. 29: Installation

ofan

Excessive

Tactile Ground Surface Indicators

Number of Blocks (Kuala Lumpur,(Beijing, China)

Malaysia)

Fig. 30: Directional

BlocksInterrupted

byFig. 31: Installation of Warning Blocks Where

Manhole Cover (Seoul, Korea)

They are Unnecessary (Hong Kong)

9） Warning Blocks Where Directional Blocks Should be Installed
Examples of warning blocks installed where directional blocks should be were observed in
Korea and China. Providing directional guidance with warning blocks creates confusion forpeople with impaired vision, who are unable to determine whether the location is a route to befollowed or a location where they are to exercise caution.

10） Installations at Medians
Examples of installation at medians were observed in the UK, the Netherlands and Hong Ko ng.
Blocks at medians can lead people with impaired vision to mistakenly believe they have passed
through the crosswalk and begin to walk along the median7.

11） Installations that Impede Wheelchair Users
Installations that impede wheelchair users include b locks installed on or at the beginning andend of sloped walkways, blocks installed on slopes that lead to crosswalks and blocks installed at
disabled parking spaces. Examples of blocks installed at sloped walkways were observed in theUSA, Australia, New Zealand, Korea, China, Taiwan, Hong Kong and Singapore (Fig. 32). Suchinstallations can be found throughout Japan but should be avoided as they impede the movementof wheelchair users9.
Examples of installations on slopes that lead to crosswalks were obse rved in the UK, the USA,New Zealand, Korea and Taiwan.
Examples of installations at disabled parking spaces were observed in the USA and Hong Kong
(Fig. 33). People with impaired vision do not use such parking spaces by themselves so blocks
that impede the movement of wheelchair users should not be installed.

Tactile ground surface indicators are indispensable in assisting people with impaired vision to
be mobile, and their profusion around the world is most welcome. However, if blocks are notinstalled properly the visually impaired may be put in dangerous situations. As described in thispaper, most countries that use blocks generally install them according to Japanese methods in
combination with unique rules of their own. As movement between countries g rows, particularly
within Europe, these inconsistent installations cause great confusion for people with impaired
vision. Increased globalization is expected to bring further opportunities for the visually impaired
to visit countries other than their own a nd common global rules are urgently needed.

Fig. 32: Tactile Ground Surface

Indicators

Fig. 33: Tactile Ground Surface

Installed on a Slope (Taipei, Taiwan)

Indicators

Installed at Disabled Parking Spaces(Hong Kong)

3. Braille Block Installation Methods(1) Braille Block Installation Methods
1) Directional Blocks
The following conditions must be met when installing directional blocks:• No obstructions a bove or within 30cm surrounding the blocks;• Direction of movement is easily recognizable;• Blocks provide guidance to the correct location;• Continuity is maintained;• No warning blocks installed at bends with interior angles of 135º or greater; a nd
• Surface area is sufficient to enable tactile perception of block direction using thesoles of the feet.

2) Warning Blocks
The following conditions must be met when installing warning blocks:• User is able to come to a stop before the obstacle (blo cks are installed 30cm
before obstacle);• Intersections are easy to identify;• Reason for the warning is easy to identify; and• Surface area is sufficient to enable tactile perception of block location using thesoles of the feet.

(2) Common Installation Errors and How to Remedy Them
1) Manhole Covers
Directional blocks must be installed in succession or people with impaired vision will be
required to search for the next block using their canes, greatly reducing their walking efficiency.
Manhole covers are one cause of such discontinuity and should generally be outfitted with Tactile
ground Surface Indicators.
【Improved Version】

Fig. 34: As in this instance, manhole covers often interrupt the flow of directional blocks,
causing people with impaired vision to lose track of which direction they should proceed .
（ Tokyo, Japan）
Improved Version: As illustrated here, manhole covers should be outfitted with Tactile groundsurface indicators.

【Improved Version】

Fig. 35: In cases like this where gratings cut across a line of blocks, warning blocks should beinstalled before and after the grating to urge caution as in the improved version at right.
（ Hokkaido, Japan）

Fig. 36: Rerouting directional blocks to avoid the manhole, as in this photograph, not only looks
unattractive but creates a winding course that greatly reduces the walking speed of people
with impaired vision. （ Hokkaido, Japan）

2) Interrupted Tactile ground surface indicators
Sequences of directional blocks must not simply trail off; they shou ld end with warning blocks
that indicate the end of the line or else people with impaired vision will spend time searching forthe directional blocks that they expect to continue on. Because people with impaired vision mustalso search for the next block when there are gaps between one directional block and another,blocks should be installed to ensure continuity.

【 Improved Version】

Fig. 37: Here there are no warning blocks installed at the end of a sequence of directional blocks.
The suggested remedy is to clearly indicate that the line of directional blocks has ended
by installing warning blocks. （ Ibaraki, Japan）

3) Jurisdictional Variations in Block Size, Shape or Color
The size, shape and color of blocks often varies with jurisdictional differences between thefacilities or roadways where they are installed. Although the selection of Tactile ground surface
indicators must take ground surface condition and tile variations into account, uniform blocks
should be used continuously wherever possible for the convenience of people with impaired
vision and to maintain an attractive environment.

Fig. 38: The situation depicted here is theFig. 39: Situations such as this one, whereorganizations

both shape and materials differ, makehaving jurisdiction over the areas toit difficult for people with impaired

the left and the right. Both types ofvisionblocks are directional blocks but theunattractive. （ Tokyo, Japan）

resultofdifferent

ones on the left with raised ovals caneasily be mistaken for warning blocks
with raised dots. The likelihood of
misreading the blocks is particularlyhigh when walking from the right tothe left. （ Tokyo, Japan）

to

walk

and

are

a lso

Fig. 40: Many examples of similarerrors

can

also

be

found

overseas. (Taipei, Taiwan)

4） Warning Blocks Where Lines of Directional Blocks Bend
Directional blocks are best installed in straight lines, yet putting a bend in the line is sometimes
unavoidable. Warning blocks should generally be installed at the point of the bend, but doing soeven where the bend is at a shallow angle will increase the overall number of warning blocks used.
Warning blocks require people with impaired vision to stop and determine what they are being
warned about, whether a danger such as a step, an intersection or a directional board. Installing
warning blocks at every bend, therefore, reduces the walking efficiency of people with impaired
vision. We researched how much of a bend was perceived to be a turn by people with impaired
vision and how much was perceived as straight and could be navigated without a marked decline
in speed. Although there was individual variation, we determined that there is generally no needto install warning blocks if the interior angle of the bend is 135º or greater.

【 Improved Version】

Fig. 41: The angle here is 130º so warning blocks should be installed as in the improved version.
（ Kanagawa, Japan）

Fig. 42: Installing warning blocks at shallow

Fig. 43: Many similar examples of the overusebends such as these means people withof warning blocks can also be found

impaired vision must frequently comeoverseas. (Hong Kong)

to a stop. （ Nagasaki, Japan）

5) Unnecessary Warning Blocks Amid Directional Blocks
Warning blocks are to be inst alled in locations where one wishes people with impaired vision totake notice. They act like a red traffic light and cause people with impaired vision to come to astop and decide immediately what the warning block is trying to tell them and whether or no t thisinformation is important to them. As mentioned in the previous section, installation of excessive
warning blocks leads to lower walking efficiency. At the same time, elimination of necessary
warning blocks leads to lower walking safety.
slope

slope

Fig. 44: In Japan, warning blocks are often installed at the beginning and end of slopes as
depicted here. A gentle slope, however, poses no danger so such warning blocks areunnecessary. Here, the four groups of warning blocks installed on the two slopes are notneeded. （ Toyama, Japan）

【 Improved Version】

Fig. 45: This is an example of an excessive number of warning blocks installed at a bend in a lineof directional blocks. Such a large number of blocks requires p eople with impaired visionto spend time searching about and can result in their losing track of which direction toproceed. The number of warning blocks should be reduced as in the improved version.
（ Kanagawa, Japan）

6) Small Blocks
Because people with impaired vision use the soles of their feet to determine whether a given
block is a directional block or a warning block, fine distinctions are difficult to make. It isdifficult, therefore, to identify blocks that cover only a very small surface area. I n particular,very small warning blocks located where users should come to a stop (such as before crosswalks,stairs or walls) risk going unnoticed by people with impaired vision who may then run into a wallor step out into a crosswalk.

Fig. 46: A directional block of but 5cm width sandwiched between warning blocks, as pictured
here, will go unnoticed by people with impaired vision. （ Tokyo, Japan）【 Improved Version】

Fig. 47: In a narrow corridor where blocks must be arr anged in an L-shape, one warning block
should be installed at the bend in the L with directional blocks above and to the right as
illustrated in the improved version here. （ Tokyo, Japan）

【 Improved Version】

Fig. 48: Because of the small area covered by the warning blocks installed before the wall, people
with impaired vision will run into the wall before noticing the warning blocks.
（ Kanagawa, Japan）【 Improved Version】

Fig. 49: In this case, the exceptionally small area covered by the warning blocks creates thedanger that people with impaired vision will step out into the crosswalk before noticing
them. （ Okinawa, Japan）

7) Block Routes
Directional blocks should be installed in straigh t lines, avoiding bends wherever possible.
Warning blocks can be installed at bends but these require people with impaired vision to come toa stop and take time searching out which direction to proceed. Installation routes should beplanned to avoid unnecessary bends.

【 Improved Version】

Fig. 50: This is an example of an unnecessary bend in a directional block installation preceding acrosswalk. The directional blocks should simply continue straight ahead as in the
improved version. （ Wakayama, Japan）

Fig. 51: Here, warning blocks have beenFig. 52: Directional blocks should not be

installed where the row of directional

installed at the edge of walkways

blocks was shifted over to the left bybecause some people with impaired

the width of one block (30cm) before avision, rather than walking directly

crosswalk

to

align

the

directionalon top of Tactile ground surface

with

the

centeroftheindicators, walk to the side whilecrosswalk. As long as the directional

sensing the texture of the blocks

blocks leading to a crosswalk are notwith their canes. This is why it is

too close to the crosswalk's edge, there

necessary to leave 30cm open on

is no need to install warning blocks

either side of the directional blocks.

and alter the course of the directionalHere,blocks in this way. （ Hokkaido, Japan）

adjacent to the directional blocks isblockslikelythetoguardrailbeanimmediately

impedimentwalking. （ Ciba, Japan）

to【 Improved Version】

Fig. 53: Here, a single row of directional blocks leads to the wall followed by warning blocks
signaling the end of the line. These blocks are unnecessary. A s in the improved version,
the warning blocks signaling the intersection alone are sufficient. （ Wakayama, Japan）

8) Crosswalks
Crossing the road is said to be one of the most stressful situations for people with impaired
vision. In general, two rows of warning blocks should be installed before crosswalks to bringusers to a stop.
【 Improved Version】

Fig. 54: Situations like this one are extremely dangerous as people with impaired vision, rather
than stopping before the crosswalk, will step out into traffic as they search for thecontinuation of the line of directional blocks. Warning blocks should be installed as in the
improved version. （ Hokkaido, Japan）

【 Improved Version】

Fig. 55: It is ordinarily best to install two rows of warning blocks before a crosswalk. Where
directional blocks are followed by only a single row of warning blocks, as shown here,
people with impaired vision may either fail to notice the warning blocks and walk out
into the road or inadvertently step over the warning blocks and come to a stop after
stepping out into the road. Two rows of warning blocks should be installed as in the
improved version. （ Hokkaido, Japan）【 Improved Version】

Fig.56: On narrow sidewalks like this, one sometimes sees installations where many Tactile
ground surface indicators are used to mark crosswalks leading in two directions, m aking it
difficult for people with impaired vision to determine where the blocks lead and what they
are meant to warn them of. In situations like this, despite the general rule of using two
rows of warning blocks before crosswalks, the number of blocks sho uld be adjusted asneeded to prioritize ease of identification by users. The improved version makes it easier
to determine the position and orientation of the crosswalks by using single rows of
warning blocks that are installed to completely cover the edge s of the sidewalk.
（ Ishikawa, Japan）

Fig. 57: Directional blocks are increasingly installed within crosswalks, something extremely
effective for people with impaired vision. When crossing the road, people with impaired
vision try to be particularly careful not to proceed in the wrong direction. Should theystray greatly from the intended path they may be unable to reach the far side of the roadand instead stray into the road. However, using blocks of the same shape as ordinary
directional blocks, a s in this example, is dangerous because users may not realize they arein a crosswalk. Specially shaped bloc ks such as those shown in Fig. 58 should be used incrosswalks. （ Miyazaki, Japan）

Fig. 58: The specially shaped directional blocks used
for "escort zones" within crosswalks.

Fig. 59: An example of a crosswalk with escortzone.

Fig. 60: Many crosswalks are outfitted with pushbutton -operated signals for pedestrians. In thiscase, a pushbutton accessible to people with disabilities has been installed. Installationsof directional blocks leading to such pushbuttons are rarely seen, yet are helpful inenabling people with impaired vision locate the pushbuttons. （ Hokkaido, Japan）

Fig. 61: Examples of numerous Tactile

Fig. 62: Covering the sidewalk with blocks

ground surface indicators installed

asbefore crosswalks, which can cause

impossible for users to determine

people with impaired vision to lose

where the crosswalks are or which

their way, are often seen overseas asdirection to proceed. (London, UK)well as in Japan. (Kuala Lumpur,
Malaysia)

in

this

examplemakes

itFig. 63: Wide medians like this one can cause people with impaired vision to mistakenly thinkthey have crossed the road, so blocks need to be installed in accordance with the proper
rules. Blocks installed over the entire surface, as is the case here, are cause for user
confusion. Accordingly, installations should be consistent i n using double rows of
warning blocks at either end of the crosswalk and single rows of warning blocks on eitherside of the median. （ Hokkaido, Japan）【 Improved Version】

median9) Intersections
Warning blocks should be installed at the intersections of lines of directional blocks. Without
such warning blocks, people with impaired vision may fail to notice the intersection and become
disoriented. A square composed of nine warning blocks should be used at right angle
intersections on broad walkways, but for narrower walkways the number of warning blocks
should be reduced as appropriate to avoi d situations where the entire walkway is covered withblocks.

【 Improved Version】

Fig. 64: Here the lack of warning blocks where the directional blocks cross means that people
with impaired vision may not notice the interse ction, particularly when moving across theframe from one side of the other. Warning blocks should be installed as in the improved
version. （ Saga, Japan）【 Improved Version】

Fig. 65: Warning blocks are sometimes not inst alled at T-shaped intersections, but should beinstalled as in the improved version. （ Chiba, Japan）

Fig. 66: Similar errors are also common

Fig. 67: Warning blocks are sometimes

overseas. (Taipei, Taiwan)

installed in this manner at T -shaped
intersections,

but

such

warning

blocks will go unnoticed by people
with

impairedvisionwhoaremoving along the path composed ofwhite

directional

blocks.

(Seoul,Korea)

10) Stairs
Warning blocks should be installed before stairs. In principle there should be two rows placed
about 30cm from the edge of the stairs. Installing more warning blocks than necessary can makeit difficult to determine what the warning is for, potentially causing people with impaired vision
to fall down the stairs as they search about for an answer.
【 Improved Version】

Fig. 68: Here, the line of warning blocks installed at the top of the stairs is truncated. A personwith impaired vision arriving at the open gap would fail to come to a stop as there are no
warning blocks. There is a real danger o f falling down the stairs. The line of warning
blocks should be continuous as in the improved version. （ Toyama, Japan）

【 Improved Version】

Fig. 69: Here there are no warning blocks at the top of the stairs. Unable to s top, people with
impaired vision may fall down the stairs. (Guangzhou, China)【 Improved Version】

Fig. 70: Warning blocks should generally be installed at the top of stairways and on the ground or
floor following the final step. Here, the warning blocks at the bottom of the stairs havebeen installed not on the ground level but on the final step. People with impaired vision
coming down the stairs will sense the warning blocks and determine that they havereached ground level. Because in fact they have an additional step to go, this may lead to
accidents such as falls or twisted ankles. Warning blocks should be repositioned as in the
improved version. （ Aichi, Japan）

Fig. 71: Warning blocks are sometimes installe d on each step of a stairway. Such warning blocks
are unnecessary. (Taipei, Taiwan)【 Improved Version】

Fig. 72: Here, warning blocks have been installed in a way that is neith er adjacent nor parallel tothe edge of the stairs. （ Nagasahi, Japan）

Fig. 73: Situations like this one where there are many warning blocks installed make it difficultfor people with impaired vision to determine what is in their surroundings. The re is adanger that they could fall down a stairs or an escalator while searching about. Double
rows of warning blocks are sufficient before both stairs and escalators. （ Toyama, Japan）

Fig. 74: In general, single rows of warning blocks

Fig. 75: Warning blocks should be installedshould be installed at the beginning andacrosstheentireend of stair landings. It is inappropriate tostairway,

install them only near handrails rather than

one-block interruption at the center

across the entire width of the stairs, asof the rows of warning blocks is due

shown here. The elderly are the primary

to the position of the handrail.

users of handrails at rail stations. Because（ Ibaraki, Japan）

as

shown

width
here.

of

the
The

of the danger of collision with the elderly,
many people with impaired vision do notuse

handrails

whenascendinganddescending stairs. （Osaka, Japan）

11) Before Escalators
Warning blocks should be installed close to the entrances to escalators.
【 Improved Version】

Fig. 76: Here the warning blocks are located too far from the entrance to the escalator, and should
instead be installed as in the improved version. （ Tokyo, Japan）

12) Errors at Platforms
Railway platforms are extremely dangerous locations for people with impaired vision. To
prevent people from falling onto the tracks, it is customary to use warning blocks alone rather
than directional blocks along platf orm edges. It is best if such warning blocks measure the JIS
standard 30cm square.

Fig. 77: Here the warning blocks measure only 15cm wide. There is the risk that people with
impaired vision may inadvertently step over the blocks and fall onto th e tracks. Warning
blocks measuring 30cm square should be used on platforms . （ Nagasaki, Japan）

13) Before Gates and Doors
Warning blocks should be installed before gates and doors to make their presence known.
Otherwise, people with impaired vision may ru n into them when they are opened.

Fig. 78: Warning blocks should be installed before gates. （ Chiba, Japan）

【 Improved Version】

Fig. 79: Here a line of directional blocks ends without warning blocks before a door. Because
people with impaired vision will continue toward the door without stopping, there is therisk that they could hit their head on the edge of the door should it happen to be open.
Warning blocks should be installed as in the improved version. （ Osaka, Japan）

14) Slopes
Many users of wheelchairs, baby strollers and four -wheeled walkers for the elderly feel that
Tactile ground surface indicators create a barrier for them. Wheelchair users, in particular, arebothered by the tendency of Braille block pr otrusions to change the orientation of their front
wheels and make it more difficult to hold a course. Other problems include the loss of bodily
stability due to vibration and the slipperiness of Tactile ground surface indicators installed
outdoors. At the same time, many people with impaired vision prefer to use stairs with clearly
defined steps when moving up or down a level. Collisions may occur between wheelchair users
and people with impaired vision using slopes. For these reasons, Tactile ground surface
indicators should not be installed on slopes.

Fig. 80: As depicted here, the protrusions on Tactile ground surface indicators can cause
wheelchair wheels to change direction, making it difficult to move forward.

Fig. 81: As shown here, directing people

Fig. 82: Installing blocks on a slope as inwith impaired vision to use thethis example is not appropriate.

stairs instead of installing Tactile（ Miyazaki, Japan）

ground surface indicators on theslope eliminates the problem ofinconvenience for wheelchair users.
（ Tokyo, Japan）

Fig. 83: Blocks are often installed at the
Figurebeginning and end of slopes, but thiscreates a barrier for

Fig. 84: Similar errors are also common
overseas. （ San Francisco, USA）

wheelchairusers. （ Ehime, Japan）

15) Elevators
Tactile ground surface indicators installed in front of elevator entrances can cause wheelchair
wheels to catch. Therefore, care must be taken to minimize the barrier to wheelchair use by
installing Tactile ground surface indicators only before the call buttons rather than across theentire width of the elevator entrance.

【 Improved Version】

Fig. 85: Tactile ground surface indicators installed in this way create a barrier for wheelchairusers. Blocks should instead be installed only before the call buttons as shown in the
improved version. （ Osaka, Japan）

Fig. 86: Warning blocks are sometimes installed inside elevators. People with impaired vision,
however, will not lose track of the e ntrance within the narrow confines of an elevator.
Such blocks are an obstacle to wheelchair use and should be removed. （ Ehime, Japan）

16) Station Wickets
One often sees Tactile ground surface indicators installed at the wide wickets designed tofacilitate passage by wheelchair users. Such blocks, however, are an obstacle to wheelchair use.
Since there is no need for people with impaired vision to use the wider wickets, Tactile groundsurface indicators should be installed at wickets separate from those d esigned for wheelchairusers.

Fig. 87: Here, the wicket where Tactile
groundsurfaceinstalled

is

from

indicators

correctlyareseparate

the

wider

wicketforwheelchairusers.

（ Ibaraki,

Fig. 88: In fact, there are many cases
where

Tactilegroundsurfaceindicators are installed at thewider, manned wickets. (Kuala
Lumpur, Malaysia)

Japan）

17) Disabled Parking Spaces
Disabled parking spaces are designed for wheelchair -using drivers who must open their doors
fully when getting in and out of their cars. People with impaired vision will never u se disabledparking spaces when alone. Blocks that create an obstacle for wheelchair users should not be
installed at disabled parking spaces.

Fig. 89: Here, the extensive installationofTactilegroundsurfaceareatdisabledparking

wheelchair users, Tactile groundcreatesaindicators
spacesbarrierforwheelchair users. （ Fukushima,
Japan）

Fig. 90: Because disabled parking spaces
establishedprimarilyforsurface indicators should not be
installed. （ Chiba, Japan）

18) Post-Construction Problems
It goes without saying that when facilities or equipment to whi ch Tactile ground surface
indicators lead are moved, the position of the blocks should also be adjusted. Nevertheless
Tactile ground surface indicators are often left in their original positions, creating confusing
situations for people with impaired visio n.

Fig. 91: Here the Tactile ground surface

Fig. 92: The area filled in with black

indicators have been left behindasphalt once contained some kind

after

they

of equipment—probably a publicmarked was eliminated. There is atelephone—yet the Tactile grounddanger that people with impaired

surface indicators were left as

visionwill

mistakenly believe

they

there

to

be

a

equipment

to

cross

the

attempt

crosswalkthatcrosswalk
the

and
road.

（ Osaka, Japan）

were

even

after

this

was removed. Suchblocks should be adjusted when
this

kind

of

equipmentisremoved. （ Nagasaki, Japan）

Fig. 93: Here it is impossible to follow the Tactile ground surface indicators to the bus stop due
to fencing that was installed later. (Hong Kong)19) Poor MaintenanceOne often sees cases where blocks have come loose o r are broken and scattered about because
regular maintenance has not been conducted after installation. This not only defeats the purposeof having Tactile ground surface indicators at all but also poses a tripping risk for pedestrians
and looks terrible.

Fig. 94: Because the Tactile groundsurface indicators

Fig. 95: Because the protrusions have

have peeleddisappeared from these warningaway before the crosswalk, people

blocks at the top of the stairs,with impaired vision may notpeople with impaired vision may

recognize

not realized that there is a stairs

that

there

is

a

crosswalk and step out into theand fall down. (Taipei, Taiwan)

road. （ Kanagawa, Japan）

Fig. 96: An example of broken blocks left
unattended. (Seoul, Korea)

Fig. 97: Broken blocks not only pose a
danger to people with impaired
vision but are also a major barrier
for wheelchair users.

Fig. 98: In snowy areas, snow removal
efforts often result in the loss ofmany protrusions. （ Hokkaido,
Japan）

Fig. 99: The use of blocks different than thoseFig. 100: This photograph, taken before

originally installed is common when

the Paris Opera House, shows theTactile ground surface indicators areunattractive result of repair using

repaired.

a different type of blocks thanThe

resultingmixofdifferent specifications and shapes canthoselead to confusion among people withFrance)originallyused.

(Paris,impaired vision. The loss of visualconsistency

is

also

unattractive.

（ Fukuoka, Japan）

20) Obstacles Positioned Over Tactile ground surface indicators
The lack of obstacles or dangers above them is a precondition for the installation of Tactile
ground surface indicator s. Nevertheless, one often sees signs or other obstacles positioned in theway. These obstacles interfere greatly with the movement of people with impaired vision.

Fig. 101: One frequently sees benches
placedabove

Tactilegroundsurface indicators at bus stops as
shown

here.

Naturally,such

obstructions should be avoided.

Fig. 102: Benches located above Tactile groundsurface indicators at a bus stop in

Fig. 103: A bus stop covering a line of
directional blocks.

Thailand. (Bangkok, Thailand)

Fig. 104: Doormats designed to keep out mud

Fig. 105: Rather than cover the Tactile

sometimes cover Tactile ground surface

ground surface indicators with theindicators at building entrances. Suchmats, the mats should be shapedmats make it difficult to feel theas shown to leave the blocks

protrusions on the blocks, however, anduncovered. （ Hiroshima, Japan）

should not be used in this way.
（Hokkaido, Japan）

Fig. 106: An automated subwa y turnstile
installed on top of a line ofblocks. (Guangzhou, China)21) Use for Other Purposes
Tactile ground surface indicators are sometimes put to uses other than facilitating the safe
movement of people with impaired vision. This can be a source of confusion for people with
impaired vision and can even lead to serious accidents. Tactile ground surface indicators should
only be used as originally intended.

Fig. 107: Tactile ground surface indicators

Fig. 108: Here, at the entrance to a store,

are sometimes used, as shown here,

Tactile ground surface indicators areto create a non-slip surface at theused to create a non-slip surface as

entrances to underground parking

in Fig. 107. (Taipei, Taiwan)

areas. （ Wakayama, Japan）