CAG Position Statement - Tactile Walking Surface Indicators

Tactile Walking Surface Indicators (TWSIs) are a feature of the built environment, often found on sidewalks, which provide tactile information underfoot or through a mobility cane to people who are blind, partially sighted or deafblind that assists with navigation and alerts people to potential hazards such as platform edges and road crossings. In order for TWSIs to be fully effective they must be designed and deployed appropriately across the built environment. Read the full Position Statement for further information and CAG recommendations. 

Position Statement on Tactile Walking Surface Indicators


Revised: March 21 2023


About the Consumer Access Group

The Consumer Access Group (CAG) is a coalition of blindness related not for profit organizations. Each partner contributes their expertise to developing position statements on blindness related concerns. These statements enable organizations and individuals to advocate with a common voice on blindness-related issues, increasing the capacity of each to more effectively promote social inclusion for Canadians who are blind, Deafblind, and partially sighted.

Issue

The ability to move safely about one’s environment with ease and confidence is essential for full participation in the community. Many people who are blind, deafblind, or partially sighted (hereafter referred to as blind) use information available from the natural and built environment such as acoustics, tactile information and visual information to assist with wayfinding.  Tactile walking surface indicators (TWSI), are a form of warning and wayfinding that can assist people who are blind to travel independently and safely in both familiar and unfamiliar spaces.  The appropriate design, use and consistent implementation of TWSI is necessary to ensure equal access to the physical environment, for people who are blind. 

Background

There are two types of TWSIs:

  • Attention TWSIs, sometimes called warning TWSIs, or truncated domes, call attention to key hazards, such as the top of a staircase or a platform edge in a subway or train station or the edge of the road at blended curbs.  Attention TWSIs consist of a grid made up of circular, truncated domes and are installed on the walking surface.

  • Guidance TWSIs, also known as wayfinding or directional TWSIs, provide information about the direction of travel through open spaces.  Guidance TWSIs are designed to guide a person on a designated path of travel.

The right of persons with disabilities to have equal access to the physical environment is set out in the United Nations Convention on the Rights of Persons with Disabilities (CRPD), which the Canadian Government (with the support of all provinces and territories) ratified in March 2010. Article 9 of the CRPD states, in part, that “parties shall take appropriate measures to ensure to persons with disabilities access, on an equal basis with others, to the physical environment, to transportation, to information and communications, including information and communications technologies and systems, and to other facilities and services open or provided to the public, both in urban and in rural areas.”

The organizations listed at the end of this document have endorsed the following recommendations concerning attention and guidance tactile walking surface indicators.

Recommendations

General recommendations for all TWSIs

TWSIs should be installed where no built or natural guiding elements exist.  It should be noted that wayfinding can be achieved through good design of facilities, including clear accessible paths of travel with built and natural guiding elements, such as edges and surfaces that can be followed tactually and visually. TWSIs are not a substitute for poor design. 

All TWSIs should: 

  • Be easily detectable from the surrounding surface by a raised tactile profile

  • Provide visual contrast from the surrounding surface (safety yellow (Munsell Colour System: hue 5.0, chroma yellow 8.0/12) is the preferred colour as it has a high conspicuity profile. However, a light colour on a dark ground surface or a dark colour on a light ground surface that provides a high contrast also works effectively as long as a light reflectance value, LRV, of 70% or greater is used in all conditions

  • Be slip resistant

  • Be used in a logical and sequential manner and be installed consistently so that they may be easily interpreted by blind pedestrians

  • Include beveled edges so as to reduce the possibility of tripping

  • Employ a texture that can be felt underfoot and be detectable with a mobility cane

  • Be recognizable as either attention TWSIs or guidance TWSIs.


Attention TWSI Recommendations

Attention TWSI should consist of truncated domes arranged in a square grid and the TWSI must extend across the full width of an accessible path of travel when approaching a hazard.

Safety yellow must be the colour used, because it has the highest degree of conspicuity in most conditions and it is also understood that yellow is used as a warning.

Attention TWSIs must comply with CSA B651-23 and ISO 23599 and be installed as set out in ISO 21542_2021 section 5.1.4, regarding size and spacing of individual domes. Attention TWSIs should be used at the following locations: 

  • Platform edges 

  • Marina dock edges 

  • The edges of reflecting pools and fountains that are unprotected at ground level

  • The top of stairs – including at the top of the stairs at mid-flight landings when there is a doorway leading on to the landing or at landings longer than 2,100 mm where there are no continuous handrails

  • Both sides of ground-level pedestrian crossings such as railways, light rail transport or street cars 

  • Blended curbs including medians and islands that are used to separate lanes of vehicular traffic

  • At the beginning of moving walkways (such as those used in airport terminals)

  • At intersecting paths where guidance TWSIs are used

  • At the top of escalators.

Attention TWSI must be installed at the locations mentioned above according to CSA B651-23 and ISO specifications.

Guidance TWSI Recommendations

Guidance TWSIs must consist of a guiding pattern constructed of two rows of parallel flat-topped elongated bars that extend in the direction of travel.

Guidance TWSIs must comply with CSA B651-23 and ISO specifications as identified above regarding width and spacing of the elongated bars.

Guidance TWSIs are recommended at the following locations: 

  • To indicate public shelters such as bus or streetcar shelters

  • Paths of travel in public transit stations 

  • Centre platforms at subway or train stations

  • Routes of travel in airports 

  • Arenas/stadiums 

  • Large open spaces, such as public squares

  • Paths of travel on sidewalks that are unusually wide or otherwise difficult to navigate

  • Paths of travel to warning TWSI at blended curbs, to indicate direction of the crosswalk (particularly when crosswalk goes off at an angle).

Guidance TWSIs must be installed at the locations mentioned in above, according to CSA B651-23 and ISO specifications identified earlier. 

Review date: March 2025
Endorsed by the following CAG organizations:

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