What are tactile indicators?
Tactile Indicators (technically referred to as Tactile Ground Surface Indicators or 'TGSI') are either raised truncated cones or elongated bars that are installed to walking surfaces.
Tactile Indicators are designed to give warning of hazards in the continuous accessible path of travel and directional information to pedestrians who are blind or visually-impaired through contact by foot or cane with the ground surface.
Pedestrians with low vision also use the colour-contrast between the Tactile Indicators and the ground surface to detect the modules visually.
What is the difference between 'warning' and 'directional' tactile indicators?
Warning Tactile Indicators, also known as hazard indicators, are textured surface features applied to walking surfaces that are intended to function much like a stop sign. They alert pedestrians who are blind or vision-impaired to hazards in their line of travel; indicating that they should stop to determine the nature of the hazard before continuing. Note that hazard indicators don't indicate, specifically, what the hazard may be.
Directional tactile indicators, also known as leading tactile indicators, are textured surface features consisting of directional bars or applied to walking surfaces to give directional orientation to people who are blind or visually-impaired. Directional tactile indicators help vision-impaired people to navigate in open spaces, and designate the continuous accessible route to be taken. Directional tactile indicators also guide people who must deviate from the continuous accessible path of travel, allowing them to safely access a crossing point, public transport access or public facility entrance.
What type of tactile indicator is best for my project?
For outdoor applications, our polyurethane or stainless-steel tactile indicators are highly recommended.
Polyurethane tactile indicators are a hard-wearing, tasteful solution that can be installed both indoors and outdoors, and are suitable for both new and existing surfaces. They are designed as a retro-fit system, meaning they can be installed after the floor surface/substrate has been laid. Our polyurethane tactile indicators are designed and manufactured in Australasia to a very high specification. The standard colour is safety yellow; however, they can be manufactured in practically any solid or metallic colour.
Stainless-steel tactile indicators are a premium, stylish solution manufactured from high-quality 316 marine-grade stainless-steel to a very high specification. As with the polyurethane tactile indicator system, stainless-steel tactile indicators can be installed indoors and outdoors; and can be installed on both new and existing substrates.
TacPro is happy to advise on the most suitable tactile indicator for your project. Contact us for more information.
Does my project require tactile indicators?
In public buildings in Australia, tactile indicators are a mandatory requirement. If the general public has use of the facility or access is provided through it; or if there are collision or tripping hazards with the potential to result in a fall, tactile indicators are also a mandatory requirement.
It is not unusual for tactile indicators to be overlooked when the plans are being drawn up. Last minute CPU (Certificate for Public Use) headaches can be avoided by checking with the architect, consultant or council as to the tactile indicator requirements for your project.
TacPro offers a free consultation service, where we are happy to advise on the standard's implications for your project, provide compliant layout guidance and seek clarification from architects, consultations or council representatives where necessary.
What are tactile indicators made from?
Tactile indicators can be made from a variety of materials, including precast concrete, polyurethane, stainless-steel, rubbers and ceramics.
So long as they comply with the relevant dimensional and spacing requirements set out in the standards, tactile indicators can be manufactured from any material that will withstand the harsh roading environment.
Durable, UV-stable and corrosion-resistant materials such as stainless-steel, brass and thermoplastic polyurethanes are best suited for tactile indicator manufacture.
The most commonly installed tactile indicator type in Australia is the polyurethane tactile indicator system and stainless-steel tactile indicator system. These are generally installed as individual studs (also known as 'discrete tactile indicators') that are drilled-and-epoxy-fixed to the substrate.
Do tactile indicators need to be yellow?
No, although, safety yellow is often the recommended standard colour due to its colour-contrast compatibility with most substrates. The standards provide colour-contrast requirements for tactile indicators.
TacPro is one of Australasia's leading tactile indicator suppliers and can manufacture polyurethane tactile indicators in virtually any colour. We are happy to discuss your individual colour-contrast requirements and provide advice to ensure you comply with the standards.
So, why are most tactile indicators yellow then?
Research by Bentzen et al (Accessible Design for the Blind, May 2000) indicates that safety yellow is so salient (even to persons having very low vision), that it is highly visible even when used in associate with adjoining surfaces. Their research found that safety yellow tactile indicators with a 40% colour-contrast against new concrete is subjectively more detectable (according to participants) than darker tactile indicators having an 86% colour-contrast against the same new concrete.
How do I measure colour-contrast?
Section 2.2 of the Joint Australian/New Zealand Standard AS/NZS 1428.4.1:2009 outlines the luminance contrast requirements for tactile indicators, as well as techniques for laboratory and on-site measurement of differences in light-reflectance values ('LRV').
The standard requires the following luminance contrast to the immediate adjoining surface:
- For tactile indicator pavers or tiles of a uniform, solid colour (i.e., integrated tactile indicators such as the 300 x 300mm peel-and-stick tiles): 35%
- For individual tactile indicator studs of a uniform, solid colour (like polyurethane tactile indicator studs): 45%.
- For individual tactile indicator studs with more than one colour (i.e., composite construction tactiles such as stainless-steel studs with black carborundum infill): 60%.
Indicative field measurements can be performed using a photographic spot meter by the method outlined in Appendix F of the standard. If you know the light-reflectance value or 'LRV' for the substrate, they can be compared with the LRV of our tactile indicator products using the Bowman Sapolinski formula. You can also use our handy colour-contrast calculate at the bottom of the Tactile 'Colour Contrast' page.
Do tactile indicators need to have a colour-contrast?
Yes, tactile indicators, whether integrated or discrete, need to provide and maintain a luminance-contrast with the surrounding substrate.
The purpose of a tactile indicator is to warn or alert blind or vision-impaired pedestrians of impending obstacles and hazards in their path of travel. Tactile indicators not only rely on their physical change in texture, but also a visual contrast for pedestrians that have low-vision or failing sight.
How much do tactile indicators cost?
Tactile indicators vary in price depending on what material they are made from and the substrate they are installed to. TacPro also provides volume-adjusted discounts based on the quantity ordered in lineal metres or LM (1.0 x 0.6m)
- Polyurethane tactile indicators range from $120.00 - $180.00 per LM.
- Stainless-steel tactile indicators range from $390.00 - $550.00 per LM.
- Precast concrete tactile pavers range from $75.00 - $120.00 per LM.
- Rubber peel-and-stick tactile tiles range from $100.00 - $250.00 per LM.
Which type of tactile indicator is most durable?
Stainless-steel tactile indicators are the most durable on the market. They must, however, be machined from a reliable source using high-quality materials. TacPro are one of Australasia's most reliable tactile suppliers because we only use 316 marine-grade solid-billet stainless-steel for our tactile indicators.
Brass tactile indicators are also very durable, although brass can vary in quality; so it must be manufactured from high-quality materials to avoid corrosion. TacPro use dezincification-resistant or DZR brass to ensure a truly premium finish.
Polyurethane tactile indicators can be extremely durable, but only if the manufacturer uses a proven, high-quality, UV-stable polyurethane. TacPro uses a specifically formulated poly-ether based thermoplastic polyurethane because it's far-superior to polyester polyurethane. This ensures that the tactile indicators don't fade or crack from UV exposure.
Stainless-steel tactile indicators with carborundum infill are popular, but they can have issues with durability. Durability in any composite construction (made from two components/materials) in the harsh roading environment inevitably relies on professional manufacturing. Statistics show that 80% of all composite construction tactile indicators fails, so we recommend using integrated or standard discrete tactile indicator products instead.
Ceramic tactile indicator tiles can be used successfully for indoor installations, but only where they are limited to foot-traffic. Exterior use is not recommended because ceramic tiles are prone to cracking and chipping.
Rubber peel-and-stick tactile tiles are the most vulnerable and unreliable type of tactile indicator. Peel-and-stick tiles are susceptible to moisture-penetration around and under the pads, causing them to lose adhesion and eventually fail. Better results are achieved with indoor application, or as a temporary outdoor solution.
Precast concrete tactile pavers are used for external applications. Precast concrete tactile paver durability depends entirely on the concrete mix-design used in their manufacture. Precast concrete tactile pavers should be 50+ MPa, 60mm thick and incorporate a UV-stability package utilising high-quality colour oxides. It's recommended that only manufacturers with extensive experience are used.
Aluminium tactile indicators are not suitable for use as tactile indicators. Despite a number of suppliers producing aluminium tactile indicators, the material is simply too soft. Any significant foot-traffic will quickly wear the walking surface, reducing slip-resistance properties and rendering the units non-compliant (and outright dangerous). Again, stainless-steel tactile indicators are the recommended option for durability.
Can I install tactile indicators myself?
Yes, TacPro has developed the easiest and most reliable tactile indicator self-install kit on the market. This tactile indicator 'KitBox' is a self-install kit that comes with everything required to complete a professional installation. Our KitBox includes a laser-cut rubber drilling template, our proprietary two-part epoxy adhesive and a rapid-shot epoxy dispensing system; alongside an easy-to-follow instruction set.
Where did tactile indicators originate?
Tactile indicators can be found all over the world; on train station platforms, pedestrian crossings, bus stations, ferry terminals and the top/bottom of just about every set of public stairs and escalators. But it all started in Japan back in 1965, when they were created by inventor Seiichi Miyake.
Originally called 'tenji blocks', tactile indicators were first installed in Okayama City in 1965. After a decade, they became mandatory in Japanese railways; and nearly 60 years later, they can be found across the globe. The system has been constantly developed and standardised since then.
In Japan, tactile indicators are mostly installed on the ground surface of pedstrian areas in the form of hard, rubber tiles of approximately 300mm square with a grid of raised domes or parallel bars on the top surface, which blind and low-vision pedestrians can touch with their cane or feel through their feet.
Tactile indicators are found at public transport hubs (train stations, bus stations etc.) and many other public places. The bars indicator a particular direction of travel, while the domes are an indicator to stop and consider the immediate surroundings/evaluate the imminent hazard before proceeding. Imminent hazards could be vehicular traffic in the case of a pedestrian crossing; railway tracks in the case of a railway platform edge; and tripping or falling in the case of stairs or escalators.
Why use tactile indicators?
People rely on visual, audible, tactile and other sensory information from the surrounding environment for their orientation. Most people who have vision-impairment are able to see colour, though colour discrimination may be impaired. Some sources report that yellow colours are the most salient as loss of vision occurs. Only a small percentage of people with vision-impairment can see nothing at all, but even that group will generally have some sensitivity to light and shade. Contrast between the walking surface and surrounding environment is critical for people who have vision-impairment for orientation, distinguishing the limits of the footpath, recognising hazards and gathering information. Contrary to popular belief, a loss of sight is not accompanied by an increase in the effectiveness of other non-visual senses. However, people who are blind or vision-impaired generally place more emphasis on information received via other senses, i.e., sense of touch. Therefore, pedestrian facilities must have consistent design features that assist people who are blind or vision-impaired with their orientation.
Walking environment - in order to negotiate the urban environment, people who are blind or vision-impaired need to be able to find their way along footpaths and across roads. They do so with the help of a variety of environmental cues, such as the property line, the edge of the sealed path, the kerb, and consistently places street furniture, i.e., parking meters. Those people that rely on their residual sight use visual contrast cues for their orientation. People who are blind or have low vision will move around either independently or with the aid of another person who will act as a guide. Those who move around independently will do so making the most of their residual sight and any mobility aids.
Mobility Aids - The most common mobility aid used by pedestrians who are blind or vision-impaired to facilitate their independent mobility is a long white cane. This is used to preview the ground in front of the person as they walk to detect hazards. Previewing takes the form of moving the cane in an arc from one side to the other, just beyond the shoulder width of each stroke. This technique will usually locate potential obstructions such as street furniture, provided that there is some element at ground level, or within 150mm of the ground, and distinct changes in level such as a kerb upstand or a step. One technique that long cane travellers use is the constant contact technique, where the user maintains contact between the tip of the cane and the ground as it is sweeping from side to side. This allows the user to detect the presence of distinct changes in texture underfoot. Once any feature has been located and possibly identified, the pedestrian will decide how to proceed.
How are tactile indicators perceived by blind/visually-impaired people?
Using the example of crossing the road, a pedestrian who is blind or vision-impaired needs to:
- Find the crossing point.
- Identify when the footpath finishes and the roadway is about to be entered.
- Determine the direction to cross.
- Determine when it is safe to cross.
- Maintain orientation while crossing the road.
- Find the opposite kerb crossing point.
Changes in texture between the tactile indicators and the surrounding ground surface are felt (i.e., using their sense of touch) through their feet or through their cane. For those with low vision, the contrast in light and colour between the tactile indicators and the surrounding ground surface is an additional advantage for safe way-finding. In addition to warning vision-impaired pedestrians of a potential hazard, areas or 'pads' of tactile indicators are often installed in pairs, positioned on the ground in a way that helps orientate the user with the directional of the crossing (or the continuous accessible path of travel) with the reciprocating pad (the tactile pad on the opposite side of the road at the opposing kerb crossing point) alerting the user that they have safely reached the other side of the hazard (in this case, the road). The raised parallel bars on directional tactile indicators help to lead or guide vision-impaired pedestrians to points of interest such as audible help points, a dedicated pedestrian crossing or an access ramp. They are also a useful way-finding tool in open areas where other tactile cues might be lacking.