Tactile Indicators Australian Standards.

Interpretation of Tactile Indicators Australian Standard AS1428.4

  1. Design Requirements of Tactile Ground Surface Indicators.
  2. Types of Tactile Indicators that are compliant with Australian Standards.
  3. Colour and Luminance Contrast requirements.

Design Requirements of Tactile Ground Surface Indicators.

Hazard Warning Tactile Indicators are specified to have a 35mm base diameter, 25mm top diameter and 4-5mm in height. These tactiles are defined as raised truncated domes having a sloped side to allow for a tactile indication of a hazard that is immediately adjacent to the direction of travel.

Discrete Tactile Indicators
Hazard Tactile Indicator

Directional Tactile Indicators are required to be 35mm in width, 285mm length and 4-5mm in height. Directional tactiles are raised bars with sloped sides that act as a guide to indicate that there is a safe route parallel to the direction of travel.

Directional Tactile Indicator
Directional Tactile Indicator

Both types of tactiles are required to be slip resistant, which can be measured  and  Slip resistance is measured as per Australian standard AS 4586. The oil ramp test is suitable for the measurement of slip resistance as per Australian Standards. This test provides ‘R’ ratings for slip resistance, which allows for materials to be classed for slip resistance as R9, R10, R11, R12 and R13. The greater the ‘R’ rating, the more slip resistance it provides and so, TGSI’s that are to be installed externally or in conditions where there is a greater slip risk, it would be more suitable to install tactiles with a high slip rating such as R12 and R13.

Types of Tactile Indicators that are compliant with Australian Standards.

There are three forms in which TGSI’s are manufactured to Australian Standard AS 1428.4 are listed below;

1) Integrated TGSI’s are tactiles that are a series of tactile indicators that are incorporated on a backing tile that consists of the same material and colour of the tactiles. Essentially, integrated tactiles are a complete unit with tactiles integrated with the tile, having a defined layout as per Australian Standards. These tactiles are relatively easy to install and are installed on a range of pedestrian surfaces to assist visually impaired persons.

Yellow integrated tactile mats on asphalt

2) Discrete TGSI’s are tactiles that consist of individual units, which are installed onto the pedestrian surface one at a time. The colour of the discrete tactile indicators, relative to that of the surrounding pedestrian surface, is particularly important due to luminance requirements specified in Australian Standards. Discrete tactile indicators that are made using two colours or materials are known as composite tactiles and are required to have a greater luminance contrast than that of discrete tactiles that are made up of only one colour or material.

Discrete Tactile Indicators NDIS Housing

3) Composite TGSI’s are discrete tactile indicators that are manufactured using two colours or materials and are required to have a greater luminance contrast than discrete tactiles that are made up of only one colour or material. Generally, composite tactiles are manufactured with a base material such as stainless steel that makes up the stem and the truncated outer sides and another material is used for the top surface as an infill for the top surface. The option to have different types of inserts for the top surface provides solutions to incorporate a material with greater slip resistance and luminance contrast.

Composite Tactile Indicators Installation with carborundum infill

Colour and Luminance Contrast requirements.

Tactile indicators are required to provide a minimum luminance contrast with the surrounding surface to comply with Australian Standards. The contrast is necessary for vision impaired persons to be able to distinguish the tactiles from walkway surface.

Integrated tactile indicators are required to provide a minimum luminance contrast of 30% when the TGSI’s are of the same colour as the surrounding surface.

Discrete tactile indicators constructed of a single material and colour must provide at least 45% luminance contrast with respect to the underlying surface.

Composite tactile indicators, a form of discrete tactile indicator, are constructed using two colours or materials and are required to have a minimum luminance contrast of 60%. The luminance of the top surface of the tactile and underlying surface are tested.

Below are examples that highlight the importance of luminance contrast between the tactile indicators and substrate. The yellow integrated tactile mats provide a clear distinction between the tactiles and asphalt, allowing people with impaired vision to identify that there is a tactile surface present so that they can determine if a hazard or safe path of travel is present. However, the black integrated tactile mats are very similar in colour to that of the asphalt and provide poor luminance contrast as they both reflect light similarly.

Yellow integrated tactile mats on asphalt
Yellow tactile mats on asphalt providing sufficient contrast.
Black tactile mats on asphalt
Black tactile mats on asphalt that do not provide sufficient luminance contrast and are not compliant.

Tactile Indicator Layout Requirements

Warning Tactile Indicators are to be installed along the full width of the accessible path of travel and set back 300 ±10 mm from the edge of the hazard. Some common hazards include the top and bottom risers of a flight of stairs, the change in gradient of a ramp, curb ramps at pedestrian crossings and escalators. Obstactles and areas that are shared by pedestrians and vehicles also require warning tactiles as they pose a hazard risk in the accessible path of travel. The exceptions to the 300mm set back requirement include train stations and ferries due to the hazard risk present, allowing for a minimum set back of 600mm to be used to avoid the hazard upon tactile detection.

Installation of discrete TGSI’s are to be in a grid layout separated by 50mm from the tactile centre, as shown in fig.3. Discrete tactile indicators must be installed at a minimum depth of 600mm and up to 800 mm in depth from the direction of approach where there are intermediate landings for stairs or ramps. An Intermediate landing that is less than 3000mm from the edge of the stairway or ramp only requires discrete TGSI’S to be a minimum of 300mm to 400mm in depth where there are continuous double handrails in place.

Integrated tactile indicators are required to be installed in a

Directional Tactile Indicators are to be installed in a 600 x 600mm grid that are spaced 50mm from the tactile centres.

Tactile Indicator Layout

Integrated tactile indicators are required to be installed in a

Directional Tactile Indicators are to be installed in a 600 x 600mm grid that are spaced 50mm from the tactile centres.

Integrated Tactile Indicators

Location requirements for TGSI’s;

Tactile Indicators are required on stairways, ramps, escalators, translators, overhead hazards and paths that are shared by pedestrians and vehicles.

Stair ways require TGSI’s on the top and bottom landings and are placed 300mm from the riser. TgSI’s are only required on intermediate landings where there are handrails present on both sides of the stairs that are continuous on both sides on the landing.

Tactile Indicator Location Requirements.

Integrated tactile indicators are required to be installed in a

Directional Tactile Indicators are to be installed in a 600 x 600mm grid that are spaced 50mm from the tactile centres.

Integrated Tactile Indicators

Location requirements for TGSI’s;

Tactile Indicators are required on stairways, ramps, escalators, translators, overhead hazards and paths that are shared by pedestrians and vehicles.

Stair ways require TGSI’s on the top and bottom landings and are placed 300mm from the riser. TgSI’s are only required on intermediate landings where there are handrails present on both sides of the stairs that are continuous on both sides on the landing.