Short Description

Tactile ground surface indicators (TGSI) are areas of raised ground surface texture treatment installed on the floor or ground surface. They are designed to provide vision impaired pedestrians with warning and / or directional orientation information via the tip of a long cane or the sole of the shoe.

More Details

TGSI may also be detected visually by pedestrians with a vision impairment when adequate contrast with the surrounding ground surface is provided.

There are two types of TGSI:

Warning or hazard indicators - (dome pattern) are installed across the path of travel to warn of an approaching hazard such as a roadway or change in level created by a stair or ramp.

Directional indicators - (ridge pattern) are installed along the path of travel to guide users across open spaces in the absence of other environmental cues.

Product selection
Tactile ground surface indicators are available in a range of materials for outdoor and indoor use.

Ground surface or flooring not yet laid:
Many TGSI come in the form of tiles that are laid in multiples to cover the required ground surface area. The thickness of the tiles usually requires that the tile be recessed into the surrounding ground surface so that the tile edge does not create a trip hazard. The dimensions of the TGSI product to be installed should be known prior to laying of the floor to ensure a suitable set-down is created.

Ground surface or flooring already laid:
A number of TGSI products can be applied to an existing floor with minimal disruption, and include:
Tiles with thickness not exceeding 3mm that are usually adhered to the floor.
Viscous applications that are moulded on site.
Discrete domes or ridges that are fastened directly onto the flooring.

Installation requirements
Refer to the Australian Standard comments about this product for installation requirements. The current recommendation is to lay the TGSI in a band 600mm wide 300mm from the edge of the first and last tread

Standards

Tactile ground surface indicators (TGSI) should comply with the current edition of the Australian Standard AS1428.4 Design for access and mobility Part 4: Tactile Indicators. This standard provides specifications on the form of TGSI and on their installation. Refer to this standard to determine the luminance contrast required between the TGSI and the surrounding ground surface and for installation details including width, length and location for a wide range of applications.

The Building Code of Australia specifies in what situations TGSI must be installed. To comply with the BCA the installation must be in full compliance with the relevant sections of the current AS1428.4.