Retroreflectometers are essential for ensuring traffic signs meet federal safety standards by measuring their ability to reflect light back to drivers. With nighttime driving accounting for 55% of fatal accidents, these tools provide objective data to help maintain compliant and safe road signage. Here’s a quick look at the top five retroreflectometers, their features, and how they can assist with field inspections:
- RoadVista 922: Measures retroreflectivity at 0.2° and 0.5° observation angles simultaneously, stores 4,500 readings, and includes GPS for location tracking. Rugged design with fast and accurate readings.
- RetroSign GRX: Offers seven observation angles, ambient light compensation, and a built-in MUTCD sign library for pass/fail assessments. Includes GPS and supports wireless upgrades.
- Zehntner ZRS 6060: Measures up to three angles simultaneously, lightweight, and offers optional telescopic handles for safer inspections without ladders.
- TAPCO Retroreflectometer: Provides dual-angle measurements in under a second, stores up to 5,600 readings, and features Bluetooth and GPS for data management.
- Toproad AT-SR-006: Compact and lightweight with a fixed 0.2° observation angle, durable design, and 8GB storage for over 99,999 test records.
These devices vary in features like observation angles, durability, and connectivity options to suit different inspection needs.
Top 5 Retroreflectometers Comparison Chart for Traffic Sign Inspection
Kentucky LTAP Road Safety Video - How to Measure Sign Retroreflectivity: Using a Retroreflectometer
Quick Comparison
| Device | Observation Angles | Entrance Angles | Compliance Standards | Weight | Battery Life | Connectivity |
|---|---|---|---|---|---|---|
| RoadVista 922 | 0.2°, 0.5° | -4° | ASTM E1709, ASTM E2540 | 5.9 lbs | N/A | USB, Bluetooth |
| RetroSign GRX | 0.2°–2.0° (7 angles) | -4°, +5° | ASTM E1709, EN 12899 | N/A | ~800 tests/charge | Bluetooth, USB |
| Zehntner ZRS 6060 | 0.2°, 0.5°, 1.0° | -4°, +5° | ASTM E1709, EN 12899 | 4.2 lbs | N/A | USB, Bluetooth |
| TAPCO | 0.2°, 0.5° | -4° | ASTM E1709 | 5.9 lbs | N/A | Bluetooth, GPS |
| Toproad AT-SR-006 | 0.2° (fixed) | -4° | ASTM E1709, ASTM E2540 | 3.7 lbs | 8+ hours | USB, 8GB internal memory |
Each retroreflectometer brings unique strengths to the table, whether it's advanced connectivity, multi-angle measurement, or portability. Choose the one that aligns with your inspection needs and budget.
1. RoadVista 922 Handheld Sign Retroreflectometer
Measurement Angles and Speed
The RoadVista 922 stands out as the first handheld device capable of capturing both 0.2° and 0.5° observation angles with a -4° entrance angle, aligning with ASTM specifications tailored for modern vehicle profiles in the U.S.. Eric Nelson, Senior Physicist and Sales Manager at RoadVista, explains:
"Because a significant portion of the vehicles on the road in the USA are now SUVs and pickup trucks, ASTM has drafted a specification that requires measurements to be performed at an observation angle of 0.5°, in addition to the traditional 0.2°."
This device provides readings in less than one second, thanks to its patented annular geometry (US Patent #7,961,328). This innovation eliminates the need to average multiple measurements when working with prismatic materials. Additionally, its photometric filter ensures precise color readings using just one white reference standard. These features make it an essential tool for meeting federal compliance requirements.
Standards Compliance
The RoadVista 922 adheres to ASTM E1709 and ASTM E2540 standards by using a photopic response with CIE Illuminant "A". This level of optical accuracy ensures that its measurements align with the MUTCD's minimum retroreflectivity guidelines. The device also includes aperture reducers (0.59 inch and 0.39 inch), making it capable of analyzing small signs or intricate symbols with precision.
Built for the Field
Engineered for rugged conditions, the RoadVista 922 combines advanced functionality with portability. It comes in a durable, watertight, and dust-proof Pelican case, complete with essential accessories. The device's internal memory can store about 4,500 measurements, while its 56-channel WAAS-enabled GPS ensures positional accuracy within 2 meters. A large LCD touch screen allows for easy, one-handed operation, making it ideal for fieldwork.
Connectivity and Data Management
The RoadVista 922 is equipped with USB, Bluetooth, and IrDA remote control capabilities, offering versatile connectivity options. It also features a built-in barcode reader for asset management and software that integrates seamlessly with GIS systems. These tools simplify inspection workflows and make it easier to track sign maintenance records efficiently.
2. Delta/Zehtner RetroSign GRX
Multi-Angle Measurement Capabilities
The Delta/Zehtner RetroSign GRX is designed to capture multiple observation angles - 0.2º, 0.33º, 0.5º, 0.7º, 1.0º, 1.5º, and 2.0º - all within a single second. Its aperture geometry mimics real-world conditions, making it ideal for detecting issues like improperly applied microprismatic sheeting. The Stray Light Compensation feature ensures precise readings even under direct sunlight by adjusting for ambient light interference. These features make it a dependable tool for accurate and standardized testing.
Standards Compliance and Performance
The GRX is built to meet key ASTM and EN standards, including ASTM E-1709, ASTM E-2540, and EN 12899. It features front-mounted entrance angle adapters that allow users to quickly switch between ASTM (-4°) and CEN (+5°) geometries. The device automatically recognizes the attached adapter for seamless operation. With a measurement repeatability of about ±3% and reproducibility of ±5%, it operates within a range of 0 to 2,000 cd·lx⁻¹·m⁻². Additionally, its integrated MUTCD sign library enables instant pass/fail assessments during field inspections. As DELTA highlights:
"RetroSign GRX is the most advanced instrument on the market and still very easy to calibrate and operate."
Field-Ready Design
Designed for on-site use, the GRX features a 5-inch WVGA touch display that remains easy to read, even in bright sunlight. It comes with an adjustable wireless extension pole ranging from 4.9 to 8.9 feet, making it safer and more efficient for inspections. The battery supports up to 800 measurements on a single charge and recharges in just 45 minutes. Additional tools include a built-in digital camera and a barcode/QR code reader, enabling users to directly link retroreflection data to specific sign assets.
Connectivity and Upgrades
The RetroSign GRX supports GPS, Bluetooth, and USB connectivity, making it easy to export data to Excel or visualize it in Google Earth using GPS tagging. Users can also unlock extra features, such as GPS capabilities or additional observation angles, in minutes by scanning a QR code provided by the manufacturer. For optimal performance, calibration blocks should be replaced every two years.
3. Zehntner ZRS 6060 Retroreflectometer
Simultaneous Multi-Angle Measurements
The Zehntner ZRS 6060 stands out by measuring three observation angles at the same time in cycles of about 3 seconds. You can opt for standard models - ASTM, CEN, or CD - or customize the angles to fit your needs, with options like 0.2°, 0.33°, 0.5°, 1°, 1.5°, and 2°. To reduce manual errors, it also features automatic color indication for accurate classification.
Standards Compliance and Calibration
This device is meticulously calibrated to meet international standards, ensuring its rapid measurement capabilities are both precise and reliable. The 6060.ASTM model includes a -4° illumination angle and observation angles of 0.2°, 0.5°, and 1°, adhering to ASTM E1709 and MUTCD guidelines. For European compliance, the 6060.CEN and 6060.CD models use a 5° illumination angle, meeting EN 12899-1 and DIN 67520 standards. Calibration is traceable to the Swiss Federal Institute of Metrology (METAS) and Germany's Federal Highway Research Institute (BASt), ensuring accuracy. The device measures within a range of 0 to 2,000 cd·lx⁻¹·m⁻².
Field-Ready Portability
Built with an anodized aluminum housing, the ZRS 6060 is lightweight at just 4.19 lbs (1.9 kg). Its 3.5-inch high-resolution color touchscreen remains readable even in direct sunlight. For added convenience, optional telescopic handles extend from 47.2 inches to 157.5 inches (1.2 m to 4 m), removing the need for ladders during operation. It performs reliably in temperatures ranging from 14°F to 122°F (-10°C to +50°C) and is powered by a high-capacity 14.4 V / 6.5 Ah Li-Ion battery.
Data Management and Connectivity
The ZRS 6060 includes 1 GB of internal flash memory, capable of storing up to 1,000,000 measurements. It connects via Mini USB, with an optional Bluetooth feature, and works seamlessly with MappingTools software for quick analysis and reporting. You can view geotagged data on platforms like Bing or Google Earth. Optional upgrades include a 5-megapixel camera and a WAAS GPS unit for enhanced tracking precision.
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4. TAPCO Retroreflectometer
Quick and Accurate Dual-Angle Readings
The TAPCO Retroreflectometer delivers readings in less than a second at two angles - 0.2° and 0.5°. This speed allows inspectors to efficiently assess more locations without compromising on precision. Using its patented annular measurement geometry (US Patent #7,961,328), the device ensures accurate readings for micro-prismatic materials without needing to average multiple measurements.
Compliant with MUTCD and ASTM Standards
This retroreflectometer isn't just fast - it’s designed to meet rigorous regulatory standards. It ensures traffic signs align with the retroreflectivity requirements outlined in the Manual on Uniform Traffic Control Devices (MUTCD). Additionally, it complies with ASTM E1709 and ASTM E2540 standards and adheres to CIE and DIN specifications. With a photopic-corrected detector and a CIE standard illuminant "A" lamp, it closely mimics the way the human eye perceives light. The device is also approved for procurement through GSA and OMNIA contracts, making it suitable for regulatory use.
Built to Last in the Field
Weighing just 5.9 lbs, the TAPCO Retroreflectometer is designed for durability and ease of use in the field. It features a color-TFT LCD touchscreen and operates in temperatures ranging from 32°F to 122°F (0°C to 50°C). To protect the device, it comes in a watertight, dust-proof Pelican™ case. With an internal memory capable of storing up to 5,600 measurements, it can handle 2 to 3 months of typical fieldwork without requiring data downloads.
Advanced GPS and Data Connectivity
The retroreflectometer includes a 12-channel WAAS-enabled GPS, offering positional accuracy within 3 meters. Its Bluetooth functionality and barcode reader enable seamless data exports to GIS systems or Excel, simplifying inventory management. By automating sign tracking and replacement planning, this device helps agencies make data-driven decisions based on precise measurements.
5. Toproad AT-SR-006 Sign Retroreflectometer
Precision Measurement in a Compact Package
The Toproad AT-SR-006 is a handheld retroreflectometer designed specifically for measuring the retroreflectivity of traffic signs. Its advanced optical measurement system, powered by a 32-bit MCU master module and embedded control software, ensures accurate readings. The device operates with a fixed 0.2° observation angle and -4° entrance angle, measuring retroreflectivity across a range of 0 to 1,999.9 cd·lx⁻¹·m⁻². With a repeatability error of ≤2% and a reproducibility error of ≤3%, it delivers reliable performance. The 32mm testing spot diameter ensures adequate coverage of sign surfaces, making it ideal for precise regulatory evaluations .
Standards-Compliant Design for Regulatory Inspections
Designed to meet industry standards, the AT-SR-006 uses Standard Illuminant A (2,856±50K) for retroreflective measurements. Its fixed geometry aligns with ASTM E1709 and E2540 specifications, ensuring compliance with federal regulations. To enhance reliability during inspections, the device includes an average calculation function, allowing users to take multiple readings and calculate a mean value for more dependable compliance assessments .
Built for Field Durability and Extended Use
Weighing just 3.7 lbs (1.7 kg) and measuring 8.7"×9.8"×3.1", the AT-SR-006 is compact yet rugged. Its anti-scratch metal casing is built to withstand the demands of fieldwork. The device operates effectively in temperatures ranging from 23°F to 122°F (-5°C to +50°C) and can handle humidity levels up to 98% (non-frosting). A built-in 3,500mAh battery provides over 8 hours of continuous operation, while smart standby management conserves power when the device is idle. This combination of durability and long battery life makes it a dependable tool for extended field use .
Streamlined Data Management and Connectivity
The AT-SR-006 simplifies data management with its 4.3-inch high-brightness LCD capacitive touch screen, which supports handwriting input for easy on-site data entry. With 8GB of internal storage, it can hold over 99,999 test records. Data export is hassle-free, thanks to its ability to transfer records in Excel format via a U-disk. Additionally, the device provides real-time temperature and humidity readings during tests, helping operators account for environmental factors that might influence results .
Comparison Table
Choose the best retroreflectometer for your needs by comparing their key specifications side by side in the table below.
| Device | Observation Angles | Entrance Angles | Compliance Standards | Weight | Battery Life | Connectivity |
|---|---|---|---|---|---|---|
| RoadVista 922 | 0.2° and 0.5° (simultaneous) | -4° (or +5° for 922D) | ASTM E1709, ASTM E2540, DIN 67520 (922D model) | 5.9 lbs (2.7 kg) | - | USB, Bluetooth |
| RetroSign GRX | 0.2°, 0.33°, 0.5°, 0.7°, 1.0°, 1.5°, 2.0° | 10°, 15°, 20°, 30°, 40°, 45° | ASTM E1709, ASTM E2540, EN 20471, ECE 104 | - | ~800 measurements per charge (45-minute charge time, Bosch batteries) | - |
| Zehntner ZRS 6060 | 0.2°, 0.5°, 1.0°, 1.5°, 2.0° | - | ASTM E1709, ASTM E2540, CEN EN 12899-1, DIN 67520 | 4.2 lbs (1.9 kg) | - | USB (Host Type A, Client Mini USB Type B), Bluetooth |
| TAPCO Retroreflectometer | 0.2° and 0.5° | -4° | ASTM E1709 | - | - | - |
| Toproad AT-SR-006 | 0.2° (fixed) | - | ASTM E1709, ASTM E2540 | 3.7 lbs (1.7 kg) | - | - |
Different devices excel in specific scenarios, making it essential to match their features to your field requirements. For example, the RetroSign GRX is ideal for comprehensive testing, offering seven observation angles and various entrance angle options . On the other hand, the RoadVista 922 simplifies inspections with its patented annular geometry, allowing simultaneous measurements at two observation angles .
If portability is a priority, the Toproad AT-SR-006 and Zehntner ZRS 6060 are excellent lightweight options, weighing just 3.7 lbs and 4.2 lbs respectively. In contrast, the RoadVista 922 is heavier at 5.9 lbs, which might be less convenient for extended field use .
Battery performance is another key factor. The RetroSign GRX stands out with its ability to handle approximately 800 measurements per charge and a quick 45-minute recharge time. Meanwhile, the RoadVista 922 offers the convenience of using widely available 12V DeWalt batteries and can store up to 5,600 measurements internally.
Connectivity options also vary significantly. Both the RoadVista 922 and Zehntner ZRS 6060 feature Bluetooth for seamless data uploads into GIS software. The RoadVista 922 goes a step further by supporting integration with Excel and Google Maps . The Zehntner ZRS 6060 enhances data transfer flexibility with Host USB and Client Mini USB options.
Conclusion
Retroreflectometers play a key role in ensuring traffic signs meet federal standards and help maintain safer roadways. By providing precise, objective data, these devices eliminate the uncertainty of visual inspections, which are only accurate about 74–75% of the time. Ensuring proper sign retroreflectivity isn't just about compliance - it's about saving lives.
"A retroreflectometer makes it clear whether a sign needs to be replaced or not." – Aleischa Kronshagen, Product Manager, TAPCO
Selecting the right retroreflectometer depends on your specific needs. For instance, if you're managing a large inventory of micro-prismatic sheeting, the RoadVista 922, with its annular geometry, can save time by reducing the need for multiple measurements. On the other hand, agencies working with tighter budgets and focused on routine MUTCD compliance checks might find the TAPCO Retroreflectometer or Toproad AT-SR-006 to be practical choices.
Beyond delivering precise measurements, retroreflectometers simplify sign maintenance through features like integrated GPS, Bluetooth, and GIS compatibility. These tools make data collection more efficient and allow for targeted sign replacements, helping agencies avoid the expense of replacing all signs at once .
Whether you're performing routine checks or detailed material evaluations, the right retroreflectometer provides the reliable data needed to keep roads safe while meeting regulatory standards.
FAQs
What should I look for when choosing a retroreflectometer for traffic sign inspections?
When picking a retroreflectometer for traffic sign inspections, it's important to focus on a few critical aspects: accuracy, usability, and regulatory compliance. Make sure the device aligns with recognized standards like ASTM and MUTCD, ensuring it delivers precise retroreflectivity readings to keep traffic signs up to safety codes.
Portability is another key factor. Opt for lightweight, ergonomic models that are easy to handle and have a long-lasting battery - perfect for extended hours in the field. Some devices also come with handy extras like GPS, Bluetooth connectivity, or data export features, which simplify inspection management and record-keeping.
Lastly, think about your budget and the features you truly need. Many modern retroreflectometers offer powerful functions at reasonable prices, making them suitable for both large organizations and independent contractors.
How do retroreflectometers enhance nighttime road safety?
Retroreflectometers are essential tools for enhancing nighttime road safety. They measure the retroreflectivity of traffic signs and pavement markings, ensuring these elements meet MUTCD compliance standards. This retroreflectivity allows signs and markings to reflect light from vehicle headlights back toward drivers, maintaining their visibility in low-light conditions.
By ensuring proper retroreflectivity, these devices play a key role in reducing accidents linked to poor visibility, ultimately contributing to safer roads for all drivers.
What sets the top retroreflectometers for traffic sign inspections apart from each other?
When it comes to traffic sign inspections, retroreflectometers vary widely in features like portability, measurement options, and data management tools. This variety allows you to pick the one that aligns best with your specific requirements.
- The Mirolux Ultra 922 is a compact and budget-friendly choice, ideal for basic retroreflectivity readings. It comes equipped with Wi-Fi, GPS, and a built-in printer for added convenience.
- The RoadVista 922 Handheld focuses on streamlined data management, featuring Bluetooth, GPS, and barcode scanning capabilities, making it a great option for inventory tracking.
- The RoadVista 932 Handheld takes things up a notch by measuring both retroreflectivity and color data, making it suitable for more advanced applications.
- The RetroSign GRX stands out with its multi-angle measurement capabilities and automatic color recognition, all accessible through a modern touchscreen interface.
- The original RetroSign model is a rugged, stand-alone device designed for high-volume or tough fieldwork, offering a wide measurement range.
These devices cater to a range of workflows, whether you need quick field assessments, detailed color analysis, or large-scale data collection. This flexibility ensures agencies can find the perfect tool for their traffic sign inspection tasks.