To promote safety, accessibility, and inclusivity in public and commercial spaces, Australian Standards mandate the installation of tactile ground surface indicators in all new builds and renovated public or private works.
These indicators serve as crucial navigational cues, helping individuals who are blind or vision-impaired orient themselves within their environment.
Warning tactile indicators act as a “stop” sign, alerting pedestrians to hazards such as pedestrian crossings, kerb ramps, stairs, and escalators.
Directional tactile indicators guide individuals in navigating open spaces, crossing points, intersections, public transport access points, and building entrances.
While these tactile indicators are essential for safety and accessibility, their effectiveness relies on sufficient luminance contrast.
Without clear contrast, people with vision impairments may struggle to distinguish tactile indicators from the surrounding surface, especially in wet conditions, poor lighting, or high-traffic areas.
In today’s article, we’ll focus on tactile indicators, exploring the importance of ensuring optimal luminance contrast, common mistakes to avoid, and best practices for compliance and effectiveness.
By prioritising compliant luminance contrast, we can create safer, more accessible spaces for everyone.
What is Luminance Contrast?
Luminance contrast refers to “the light reflected from one surface or component compared to the light reflected from another surface or component”, as defined by Australian Standard 1428.1.
Unlike colour contrast, luminance contrast focuses on the differences in the lightness or darkness of two adjacent surfaces, irrespective of their colour. This means that even if two surfaces share the same colour, they can still have different luminance values depending on how much light they reflect.
Optimal luminance contrast is essential for individuals with vision impairments, as it allows them to distinguish between surfaces based on brightness rather than colour.
Why Luminance Contrast Matters for Tactile Indicators
Tactile ground service indicators (TGSIs), commonly referred to as tactile indicators, serve as crucial navigational aids for individuals with vision impairments, acting as both visual and textural cues.
For more information on the application of tactile indicators, download our Product Application Guide.
When installed following the Australian Standards, tactile indicators with high luminance contrast are much easier to detect, even for those with difficulty perceiving specific colours.
A stronger luminance contrast helps the visually impaired to identify impending hazards, navigate changes in flooring, and adapt to different lighting conditions with greater confidence and ease.
Aside from tactile indicators, other building elements and products required to meet minimum luminance contrast requirements include stair nosings, signage, flooring materials and finishes, handrails, and more.
How to Calculate and Test Luminance Contrast
To determine the luminance contrast between two adjacent surfaces, such as a tactile indicator and its surrounding floor finish, the Bowman-Sapolinski equation, also known as the Luminance Contrast Ratio (LCR) equation, is used.
Steps to Calculate Luminance Contrast
- Choose the right conditions.
Start with a clean surface and conduct testing under actual or representative lighting conditions to ensure accurate results.
If you are installing products outdoors or in an area where they can get wet, you will need to take both dry and wet readings to account for environmental factors, ensuring accessibility and safety in all situations.
- Measure the Luminance Reflectance Values (LRVs) for both surfaces.
LRVs can often be obtained from the manufacturer or by referring to an LRV guide.
Alternatively, for precise measurements, you can use a colourimeter or spectrophotometer to measure the LRV using a sample or on-site testing methods.
LRV values typically range from 0 to 100, where 0 represents absolute black (no light reflected) and 100 represents absolute white (all light reflected).
To ensure accuracy, we highly recommend taking 10 individual LRV readings to calculate the mean LRV, accounting for any variability.
- Identify the lighter and darker surfaces.
The lighter surface usually reflects more light (higher LRV), while the darker surface reflects less light (lower LRV).
- Apply the Luminance Contrast Ratio (LCR) equation.
C=125 (Y2 – Y1)/(Y1+Y2+25)
Y1 and Y2 are the Light Reflectance Values (LRV) of the two surfaces.
- Interpret the results.
The resulting LCR value indicates the degree of contrast between the two surfaces.
A higher LCR value indicates greater contrast, making it easier to distinguish between surfaces, while a lower LCR value suggests less contrast.
A minimum of 30% contrast is required to comply with the Australian Standards.
Use Our FREE LRV/ Luminance Contrast Calculator
To help you meet AS/NZS 1428.4 requirements, our free online calculator provides luminance contrast values for dry and wet readings—complete with a Pass or Fail result based on Australian Standards.
- Pre-loaded with LRV data for Classic products – This includes Classic Tredfx Tactile Indicators and Stair Nosings, with LRVs for both dry and wet conditions.
- Instant readings – Efficiently determine whether your products meet the required luminance contrast levels.
- PDF report – You can opt to have the full report with your results emailed to you for documentation.
Click here to use Classic’s LRV/ Luminance Contrast Online Calculator.
Need help? Watch our quick, easy video tutorial, or contact our friendly team for tailored advice.
Australian Standards for Tactile Indicator Installation & Luminance Contrast Requirements
To meet AS/NZS 1428.4 standards, tactile indicators must adhere to the following installation requirements:
- Installation across the entire width of the path of travel, allowing them to be detected underfoot or with the tip of a cane.
- The surface must be slip-resistant.
- The top of the tactile indicators must sit no more than 4-5mm above the base surface.
Luminance contrast standards:
- Integrated (tile) type tactiles: Minimum 30% luminance contrast with the surrounding substrate.
- Individual tactiles—one colour: Minimum of 45% luminance contrast with the surrounding surface.
- Individual tactiles—two colours: Minimum of 60% luminance contrast with the surrounding surface.
Learn more about the importance of tactile indicators in Australian Standards.
Installing Tactile Indicators: Best Practices to Get Your Luminance Contrast Right
Before installing the product (e.g. tactile indicators or stair nosing), test the LRVs of all products and surfaces involved under real lighting conditions.
- LRVs can often be obtained from the manufacturer or by referring to an LRV guide.
- Alternatively, for precise measurements, you may use a colourimeter or spectrophotometer to measure the LRV using a sample or on-site testing methods.
Randomise the selection of product samples for accurate testing.
- Samples for LRV readings should be selected randomly from different batches or production runs to account for variations in manufacturing processes and materials.
- Before taking measurements, ensure the surface is clean and free from contaminants or surface treatments that could affect light reflectance.
Measure the luminance contrast with both the substrate and surrounding materials, including the stair or floor finish being used.
- Attain 10 individual readings to get the mean LRV for accurate results.
- If you are installing products outdoors or in an area where they can get wet, the mean LRV must be based on wet conditions.
Don’t want to take your chances? Classic Architectural Group is here to support your project with tailored product design and compliant installation services, including on-site LRV and luminance contrast testing, which are available Australia-wide.
Avoid These Common Mistakes on Site
To ensure compliance with luminance contrast requirements, avoid these common mistakes during installation:
- Choosing colours with similar LRVs – Selecting products with colours that have similar Light Reflectance Values (LRVs) can result in insufficient luminance contrast.
- Using glossy finishes – Glossy or reflective finishes can increase glare and reduce the perceived contrast, making tactile indicators harder to detect.
- Neglecting wet LRV readings – When installing products outdoors or in areas prone to getting damp or slippery, take wet LRV readings to account for all conditions.
- Ignoring poor lighting conditions – Ensure luminance contrast is tested under various lighting conditions, including low light, to guarantee effectiveness in all environments.
By avoiding these pitfalls, you can ensure your tactile indicators meet the Australian Standards and accessibility requirements, providing all users maximum safety and visibility.
On the other hand, failure to comply can result in serious safety risks, including preventable slips, trips, and falls, which may lead to costly liabilities and legal consequences.
Compliance Begins with Classic Architectural Group
Ensuring compliance is more than a legal obligation or just another check box—it’s our shared commitment to creating safer, more accessible spaces and promoting inclusive communities for everyone to enjoy.
At Classic Architectural Group, we specialise in end-to-end floor and stair safety solutions, spanning consultation, design, manufacturing, supply, and installation services Australia-wide.
To learn more about luminance contrast testing:
- Enrol and watch our free Luminance Contrast webinar—and earn CPD points!
- Try our free LRV/Luminance Contrast calculator online to get instant results.
Whether you’re looking for tactile indicators, stair nosings, entrance matting, or other trusted products, we’re here to help you get a step ahead.
For a no-obligation consultation, quick quote or more information on any of our products, please contact us by calling 1300 244 377 or emailing us at info@classic-arch.com.
