Tactile Indicators / TGSI:
What you need to know
Tactile Ground Surface Indicators ( TGSI ) are everywhere in the public environment: on waiting platforms, at pedestrian crossings, ramps and stairs etc. Most people understand the role tactiles play in assisting vision impaired pedestrians to navigate the urban landscape and avoid hazards. What's less understood about tactiles is the need for precision when it comes to placement, colour, size and quality.
Vision impaired pedestrians rely on consistency for accurate interpretation of the cues provided by tactiles. Complying with Australian Standards is an essential part of the product selection and installation process. To maintain consistency, a number of factors need to be considered:
Tactiles need to be manufactured to precise specifications to achieve adequate prominence without causing a tripping hazard.
2 CORRECT INSTALLATION
Tactiles must be installed with the correct spacing between each unit. Inconsistent spacing has the potential to cause misinterpretation which can lead to confusion, or worse - accidents. It's important that the installer is aware of the Australian Standards to ensure that a consistent layout is achieved.
Below are some examples of incorrectly installed tactiles that do NOT meet Australian standards:
This diagram below illustrates the general TGSI pattern layout for Discrete and Integrated Warning TGSIs generally used within Australia. AS/NZS 1428.4 (2002) is widely regarded as the definitive guide in Australia for the layout, placement and positioning of TGSIs. For greater detail see AS/NZS 1428.4 (2002).
Note: there are many installation methods for attaching TGSIs to a surface/substrate. Please ensure when installing TGSIs that the installation method is applicable to your surface/substrate.
- DON"T FORGET TO REFER TO NCC & BCA LAWS AND LEGISLATION
3 LUMINANCE CONTRAST
Luminance contrast or LIGHT REFLECTIVE VALUES ( LVR ) contribute to the efficacy of tactile indicators for vision impaired pedestrians. The reason for this is that a large percentage of vision impaired people still retain partial vision and can detect the contrast provided by suitably coloured tactiles. When architects and specifiers select a colour, it's important to factor in the colour of the substrate. Failure to consider the background colour could result in insufficient contrast.
The general requirements that apply to tactile indicators are as follows:
It shall have the luminance contrast to the base surface as follows:
i) Where the integrated TGSIs are of the same colour as the underlying surface - not less than 30% across its entire area.
ii) Where discrete TGSIs-not less than 45%.
iii) Where discrete TGSIs are constructed using two colours or materials, the raised surface shall have a section that has 60% luminance contrast for a diameter of 24mm to 25mm....
DTAC® products are available in a range of colours, allowing specifiers to select according to requirements. The luminance of DTAC® products conforms to AS 1428.4 2013.
4 SLIP RESISTANCE
An essential consideration when selecting tactile indicators is the level of slip resistance provided. Tactiles are often placed at hazardous locations such as bus and rail platforms, escalators, top of stairs and pedestrian crossings. It's essential that tactiles do not increase the chance slip and fall accidents, especially in wet conditions.
DTAC® tactiles conform to slip resistance requirements. Ratings are as follows:
|Polyresin / Urethane||R12|
Due to the nature of their application, tactile indicators need to withstand harsh conditions including constant foot traffic, heavy rolling loads, extreme UV levels and other natural elements such as wind and rain. Choosing hard wearing, UV Stabilised Tactiles is essential to maintain appearance and functionality. Poor quality products suffer degradation over time. Worn surfaces and faded colours eventually render tactiles non-compliant. DTAC® tactiles are extremely hard wearing and UV stabilised, meaning they have a very long service life.
DTAC® Tactiles conform to:
i) Building Code of Australia D3.8 (Read the extract)
ii) AS/NZS 1428.4.1 2009
iii) AS/NZS 4586 2013
MAKE THE QUALITY CHOICE
If you want assurance that your tactiles will comply with Australian Standards, make sure you select a quality product such as DTAC®. ABS West is the exclusive distributor for DTAC® products in Western Australia, where you can speak to industry professionals who are conversant in the relevant compliance codes. You will have peace of mind, knowing that your tactiles are installed correctly, in accordance with required standards. Likewise, if you are seeking a product with a very long service life, avoid cheap alternatives that will degrade and require early replacement. Contact ABS West for further information.
DTAC® is the only tacitle company on NATSPEC.
Disclaimer: no one should act or reply upon the information contained within this document without first referring to the current AS/NZS 1428.4 and satisfying themselves that any proposed installations are in accordance with the Australian Standards or with the applicable building regulations, including the Building Code of Australia (BCA), as they apply from one situation to another. Furthermore, the information provided is solely for the purposes of TGSIs and is not related to the design, configuration or formation to stairs, handrails, ramps and accessible paths depicted therein.