Tactile Ground Surface Indicators or TGSI are used to assist the visually impaired or blind on their way around a place. These have been specifically designed so as to make them aware of immediate obstacles on the path or even hazards.
Tactile Ground Indicators are manufactured using different materials that are highly durable in nature. These indicators are installed on the ground surface and resemble a long sequence of slightly raised bars or small mushroom-like domes. Just like paved units on the floor, Tactile Ground Surface Indicators are drilled into the surface of the ground to fix them permanently. In many cases, you might also find these ground indicators to be drilled along into the floor mattress on the ground.
Why are TGSI used?
In several countries across the world, many aged and elderly people are often found to have poorer levels of vision, or may even suffer from blindness. Researchers and experts have projected that the population of the visually impaired is expected to grow in the upcoming years, so some means was required to facilitate their safety while moving around.
Tactile Ground Surface Indicators are basically used as a means to alert them or offer navigational information so that they can continue to move ahead safely. Laid across the floor, it becomes easier for those with poor vision to feel the TGSI by their walking stick or sole of the feet and sense any potential danger. The raised surfaces of the TGSI enable them to feel the difference in the texture of the surface they are traversing on, thereby indicating an alert.
Apart from the changed surface texture of the TGSI drilled into the ground, there are other forms of Tactile Ground Surface Indicators that use differences in colour codes to convey navigational instructions. Those who have limited vision can sense the contrasting colour schemes to understand which direction to go.
Where are TGSI used?
TGSI are mostly used in public zones, to indicate pedestrians of spots such as road crossings, curb ramp intersections. Besides, access facilities like elevators, staircase, escalators, and ramps are also used to indicate with the help of TGSI. You will also find Tactile Ground Surface Indicators being used in bus stops, tram and train stations as well as ferry stops.
What are the different categories of TGSI?
Tactile Ground Surface Indicators are basically of two categories, namely – Warning tactile indicators and Directional tactile indicators.
- Warning tactile indicators – These are also popularly referred to as Decision or Hazard Tactile indicators. These are typically installed on the surface of the ground like raised patterns in the form of a grid and are no more than 35 x 5 mm in dimensions. These enable visually impaired pedestrians to understand if there is a potential hazard in front of them. Upon encountering Warning Tactile Indicators, pedestrians need to stop immediately and discontinue in their path of walking. However, these do not indicate what the danger is. we have to install 300mm x 300mm ≅ 1 square feet so total 36 Stud needed. But when change direction or take turn like left or right or dead end. then at that area we have to install 600mm x 600mm ≅ 4 square feet so total 144 Stud will be needed.
- Directional tactile indicators – Directional Tactile Ground Surface Indicators are also called Leading Tactile and are typically installed along the direction of travel, as a sequence of small raised rectangular bars or strips on the floor. Following these indicators, a visually challenged person can easily navigate safely along a path that is free of hurdles. These are mainly used to offer directional information in open spaces where other means of navigational guidance are insufficient. A person can simply follow the directions offered by Leading Tactile Ground Surface Indicators, and learn when they have arrived at major public facilities or need to deviate.
We have to install 300mm x 300mm ≅ 1 square feet so total 4 Strip needed for Straight pathway. But make sure there is not any hazards surface on straight pathway.
for Tactile Ground Surface Indicators are also under act of Government of India NBC-2016
But when change direction or take turn like left or right or dead end. then we can check the area shape like
- ‘+‘ Shape Intersection Area : 2700mm x 2700mm ≅ 9 square feet so total 324 Stud will be needed.
- ‘L‘ Shape Intersection Area : 1200mm x 1200mm ≅ 4 square feet so total 144 Stud will be needed.
- ‘T‘ Shape Intersection Area : 1800mm x 1800mm ≅ 6 square feet so total 216 Stud will be needed.
Refer by : NCB – 2016
Basic factors to consider while installing TGSI
Certain important considerations must be made before installing suitable Tactile Ground Surface Indicators, like:
- Area – Whether the area needs tactile indicators or not is extremely crucial and is solely determined by a qualified architect. If TGSIs are installed in an area which does not need them, it can possibly lead to more harm than good and generate confusion.
- Materials – TGSI should be procured from experienced suppliers so that the correct materials are used. This will ensure that there are no chances of slipping or tripping over the indicators since these are mostly used by people with limited or no vision. Moreover, the durability of the materials also counts.
- Installers – Only experienced and reputed installers must be offered the responsibility of installing TGSIs. This is to make sure that the work is done aesthetically and is flawless enough to provide seamless navigation to those in need.
- Colours – The right shades of colours will provide the appropriate level of contrast so that people with impaired vision can easily detect the Tactile Ground Surface Indicators.
Apart from these few considerations, the expenses are also important while installing Tactile Ground Surface Indicators for the best mode of independent and safe access.