Spectrophotometric Color Measurement Enhances Traffic Sign Visibility and Protects Public Safety

Color measurement accuracy is important for traffic signs because drivers need to see and comprehend information quickly while traveling at high speeds. Image Source: MaxPixel user Nikon D90

No matter where you are in the world, the color of a traffic sign can instantly tell you roughly what that sign means, even if you’re unable to read the symbols and text written on it. Seeing a flash of red on the side of the road up ahead almost always signals to the driver that a full stop is coming up. Meanwhile, a green sign tells you to proceed, a yellow sign tells you to slow down, an orange sign urges extreme caution, and blue signs tell you where you are. Adhering to the same basic color language worldwide helps drivers follow the rules and stay safe on the road.

Yet, for these color rules to translate across languages and countries, traffic sign manufacturers need to ensure color measurement accuracy for every sign they produce. Failure to accurately match the sign's color to the official standard set by transportation departments could lead to driver confusion or accidents. To prevent these issues, transportation departments have set rigid requirements on the color of traffic signs. You need a spectrophotometer/colorimeter to determine if your color meets these requirements. Failure to do so could result in lost sales or fines for noncompliance.

The reflective nature of some traffic signs can make it difficult to accurately measure color. Image Source: Unsplash user Kyle Glenn

Spectrophotometers Ensure Accurate Traffic Sign Coloration

Many years before Richard Hunter introduced the L a b color system to the world, governments understood the need for uniform colors for traffic control. Red, Orange and Yellow were defined in terms of the color system used in the 1930s, which was then luminosity, dominant wavelength, and purity. These became the Yxy system of color measurement. Even today, all traffic signage, including retroreflective designs, is still reported in Yxy, though the overwhelming majority of current color specifications are reported in L*a*b*.

There is no universal red color for a stop sign worldwide. Each country's governing body specifies its own hue, dominant wavelength and purity tolerances, but inside that country, the color is uniform. This practice ensures that there are predefined visual differences between the primary red for stop, yellow for yield, and orange for caution meanings.

Conspicuity is enhanced when contrasting color stripes are added between primary colors. Low-light recognition is achieved by ensuring the primary signage uses fluorescent colors.

Analyzing Retroreflective Surfaces

In the USA and many other countries, retroreflective traffic signage is required, which enhances nighttime visibility when vehicle headlights illuminate the signs. Without the right spectrophotometer/colorimeter, it can be more difficult to obtain the objective color data you need, as the reflected light could make the signs appear lighter in color than they actually are. Optical geometry featuring a 0°/45° configuration is required for these measurements.

Tools like spectrophotometers can help you create consistent signs and earn the trust of safety departments around the world. Image Source: MaxPixel user Canon EOS 550d

Analyzing the Durability of Traffic Sign Color

Another challenge traffic sign manufacturers face is that paint and other colored materials can fade over time, negatively impacting how drivers perceive the signs. On average, high-quality reflective materials and colors can last about 10 years in the field without requiring repairs or replacements. Therefore, you should test your signs to ensure their colors withstand the elements for at least 10 years in order to meet the Department of Transportation's expectations.

While waiting a decade to test your sign color is impractical, you can use a spectrophotometer to test initial durability after exposure to the elements. You can also employ artificial aging environments to simulate prolonged exposure to stressors and evaluate premature color fading. Inadequate results can inform future production adjustments to improve your processes and enhance durability.

When Safety Depends on Color: The Game-Changing Agera L2

HunterLab's next-gen Agera L2 spectrophotometer was designed to offer a specific measurement mode to increase accuracy and precision for color measurement in the traffic sign industry.

Industry-Specialized Intelligence

Traffic sign manufacturers face critical color measurement issues that require specialized approaches. We've designed this spectrophotometer/colorimeter to address the key challenges head-on, with reference-grade 0°/45° circumferential geometry that most closely reflects human color perception.

Simplify accurate data capture on dark signs or elements with Dark Performance Mode. This capability allows manufacturers to have confidence in their outcomes for samples that range from dark blue informational signs to the deeper blacks, browns, and purples on high-contrast lighter backgrounds.

HunterLab tests the D65 source mode at the factory on fluorescent yellow-green, yellow, and orange retroreflective samples to ensure the highest inter-instrument agreement in the industry for these demanding colors, using Certified Grade ‘A’ CIE D65 illumination for objective quantification of appearance under true daylight conditions.

Measurement Precision by Design

Agera L2 is the result of intentional engineering based on decades of spectrophotometric expertise and careful consideration of industry needs.

We’ve designed this spectrophotometer with sample preview capabilities. The high-definition built-in camera helps users ensure consistent and accurate sample presentation to help minimize measurement discrepancies.

Agera L2 also boasts an industry-leading area of measurement. Capture data on 4 to 16 times more surface area than other models to minimize sample averaging. The Essentials TotalView 360° Auto Rotator Accessory allows the user to average out orientation effects in directionally sensitive, retroreflective materials without manual repositioning. The platform will automatically rotate samples at the specified degree and interval to support more consistent color data.

Advanced Features to Support High Efficiency

Efficiency improvements are always a business goal, and the Agera L2 has advanced features designed to support those objectives.

A focus on operator experience and streamlined workflows makes quantification and analysis faster and easier. Readouts take less than 3 seconds to display and include the effects of texture on appearance. Users can also capture 60° gloss data in a single measurement — all with intuitive, one-touch operation and user-friendly navigation that slashes measurement and training time.

Additionally, this spectrophotometer/colorimeter has Easymatch Essentials L2 software built in, allowing it to function as a fully self-contained color workstation. Operators can analyze data directly on the device with no additional connection to an outside PC required. A connectivity suite further accelerates production. Easily export data or add a keyboard or mouse with USB ports if preferred, or connect to SPCs/LIMS systems via Ethernet to document results directly. Operators can also connect a monitor via the built-in HDMI port.

Long-Term Value and Reliability

HunterLab's Agera L2 is built for exceptional value and long-term reliability, with:

• Application versatility: This spectrophotometer/colorimeter seamlessly integrates into your existing workflows, so you can quantify color data at every critical manufacturing point.
• Role-based user management controls: Protect your data integrity with built-in security controls customizable based on user role.
• Generous storage capacity: Easily access readout history directly from the equipment thanks to 32GB of storage for retaining up to 4 million records.
• Rugged construction: This device is engineered to withstand industrial production environments, with a sealed optical engine and enclosed housing to help protect against damage.
• Signature HunterLab support: Our experts are available for technical guidance and support throughout your ownership.

HunterLab Precision

In the traffic sign industry, trust and reliability are absolutely essential. Because traffic signs are vital for driver safety, manufacturers need reliable color measurement methods to optimize product performance.

For more than 70 years, HunterLab has provided the highest-quality spectrophotometers on the market for manufacturers in the safety industry, including the Agera L2. Our tools quantify color with maximum precision, ensuring that every traffic sign meets the exacting standards set by transportation departments worldwide. Contact us today to learn more about our innovative technologies, and let us help you select the perfect spectrophotometer/colorimeter for your company’s needs.