How TGSI with luminance contrast are helpful for partially blind people?
Would you like to consider pedestrian safety a priority?
People with vision loss learn to navigate a world created for seeing people, and they rely on certain design aspects to guide them, such as TGSI’s before crosswalks. There are international standards in place to help keep these signs and cues consistent around the world, and designers should follow them when creating settings that are accessible to people with vision loss.
You must first understand how persons with vision loss explore the environment in order to build spaces that are accessible to them. To begin, understand that most persons who are partially blind or have other vision problems have some degree of vision. Because they solely depend on their vision in part, some visual cues can be used. Second, because individuals with vision loss navigate the world using textures and audible signals, increasing the use of these components can make a space easier to navigate.
Tactile Ground Surface Indicators (TGSI’s) - An Essential Solution:
It is meant to help people with low vision explore the built environment safely using visual and sensory indications. It is a common misconception that those who are legally blind are completely blind. Though this is possible, it is more likely that a totally blind person can still detect color shifts and differences. Luminance contrast can be applied as a design element to make specific architectural areas easier to detect for those with limited vision.
Where does luminance contrast come into play?
Design for Access and Mobility specifies a few areas in which a minimum luminance contrast value must be met. These are the areas in question:
- A 50- to 75-mm broad nosing strip with a 30% LC is required for each stair step.
- A 50-mm band with 30% LC is required for doorways.
- The integrated floor tile type requires 30 percent LC; the single-colored discrete type (individual buttons) requires 45 percent LC, and the composite-discrete (two colored buttons) type requires 60 percent LC.
- A 30% LC against the wall backdrop surface is required for signboards.
- Visual indications are required for glass panels that could be mistaken for an opening. A visual indicator glazing band requires a 30 percent LC against the immediate floor surface.
- Unless they are self-illuminated buttons, lift buttons require a 30% LC around their edges.
- The toilet seat requires a 30% LC to the pan, surface, or sidewalls behind the pan when observed from the doorway.
Here are a few places where you may use contrast to make your outdoor environment more navigable:
- To illustrate a difference in function, use color contrasts. Add a bright white or yellow line to the edge of the curb to distinguish it from the black pavement, which can be helpful in differentiating a sidewalk and a barrier for a visually impaired individual.
- Add a stunning contrast to the stairwell’s edge. A person with a vision impairment may have difficulty distinguishing the depth differences on a stairway or step. To assist, provide a visible, high-contrast indication to the step’s edge.
- Use lighting contrasts or luminance to help people recognize situations where their safety may be threatened. Increase the amount of light at crosswalks and other such locations for persons who have trouble seeing. It’s important to keep illumination to a minimum while enhancing contrast.
- Add illumination to the ground for contrast. LED lights placed in places with contrasting colors will aid persons with vision impairments in seeing the contrast even after the sun has set and the paint is no longer visible.
- To indicate variations, use contrasting textures. Texture adjustments are required in some areas, such as crosswalks, to meet Accessibility criteria. Texture changes are just a handy indicator of elevations or traffic-feature changes in other regions.
- To show a transition between areas allocated for walkers, cyclists, and other purposes, utilize TGSI’s. TGSI’s can be used for more than just crosswalks and bubble pavement. Extended bumps can also be added to walking paths to assist those with low eyesight in determining where they can safely walk. This can assist people with vision impairments in remaining safe and avoiding causing a hazard to those riding bicycles or motorcycles.
Also, let’s check a few etiquettes for shared spaces. Keep the following etiquettes in mind while building outdoor spaces to meet the demands of blind people:
- Textures should not be used in regions where they are unnecessary.
- Make sure the paths aren’t too curved.
- Add no boundaries that could be more dangerous than beneficial.
- Around stairways, use tactile and visual signals.
- At the top and bottom of the stairwell, use a striped texture.
- Each step’s edge should be marked with luminance contrast or another textured warning indicator.
- To mark the boundary of stairs, use contrast.
- All stairwells should have railings.
These universal design and inclusive design concepts make it easier for everyone to recognize crucial characteristics of a structure, making it a safer and more intuitive environment for everyone.
It should now be evident that crossing the street poses a significant barrier for the blind and visually impaired, and not just because they must cope with automobiles. Finding the street’s border and crosswalks, as well as maintaining on course during the crossing, are all critical duties. When designing an accessible roadway, all of these considerations must be taken into account.
As our population ages, luminance contrast will become a progressively essential component of the built environment.