Retroreflectometers for Road Traffic Safety

Delta Lead

DELTA provides a highly reliable range of retroreflectometers for measuring retroreflection of pavement markings and traffic signs.

Making sure your markings and signs are performing according to current standards helps to guide traffic safely, day and night, and reduce the number of accidents, injuries and fatalities on the road. Knowing the condition of your road assets allows road owners to make sensible decisions related to road maintenance.

Retroreflection measurement of pavement markings and traffic signs

Three decades ago, DELTA was first to launch a retroreflectometer and we have since continued to be deeply involved in forging the international standards on retroreflection measurements of pavement markings and traffic signs.

As a global leader in the supply of retroreflectometers and the preferred choice of professionals, we invite you to use our instruments, knowledge and experience.

Continuous measurements of pavement markings

DELTA's LTL-M mobile retroreflectometer for measuring retroreflection of pavement markings is the latest model in our well-known LTL-range of instruments. LTL-M is built using a patented technology combining a flash light system, fast digital camera technology and real-time digital image processing. The result is a measurement system delivering hitherto unparallelled accurate measurements.

LTL-M is easy to mount on any type of standard vehicle using fittings supplied with the system. It is easy to calibrate in a simple, one-step process and is very user-friendly when it comes to operating the instrument.

LTL-M measures the retroreflection of pavement markings continuously with a measurement width of 1m / 3.3ft. It can measure double lines simultaneously, reports individually and records the geometry of the markings. LTL-M in addition records the presence of raised pavement markers (RPM) also referred to as cat eyes or road studs.

LTL-X Mark II and LTL-XL retroreflectometers for pavement markings

In 2008, DELTA launched its latest new handheld model for measuring retroreflection of pavement markings. LTL-XL measures night (RL) and day (Qd) visibility of all types of dry and wet pavement markings.

If you need to measure retroreflection from high-profile markings or measure during continuous rain, the recently upgraded DELTA LTL-X Mark II is the answer.

Both instruments make use of LED technology, which makes the instrument almost maintenance-free. It allows you to work efficiently with measuring times of 1s to 3s and a large memory of more than 200,000 measurements. Calibration of the instruments is a one-step process taking less than one minute.

RetroSign GRX retroreflectometer for road traffic signs, high-visibility clothing, licence plates and reflective tapes

DELTA's brand new RetroSign instrument is offered in three base models: GRX-1, GRX-3 & GRX-7, where the digit in the name tells the number of observation angles active. RetroSign GRX is the most advance instrument on the market currently and still very easy to operate.

It adds new features allowing users to undertake a more complete measurement programme on, for example road traffic signs. It offers automatic colour recognition, picture of sign, background and legend colour retroreflection and contrast, scanning of barcodes and QR codes for asset management, a US sign library and much more.

RetroSign GRX is scalable. The instrument may be purchased as a base model and can later easily be upgraded with additional features by simply scanning a barcode sent by DELTA.

GRX can be delivered with an app for transfer of data to a tablet and the option to instantly send date to the company back-office for analysing and filing.

Marking Thickness Gauge and Road Marking Control Kit

If the quality of markings has to be checked, DELTA can deliver our Marking Thickness Gauge for measuring the thickness of the marking material and the Road Marking Control Kit for checking additional parameters related to markings.

Single-handed operation and single-touch retroreflectometers

DELTA's instruments have been developed with the user in mind. The instruments come with single-handed operation and single-touch controls, which makes the operator work easily and simply. Our instruments are offered as a base model allowing the user to add features according to his or her needs and financial capacity.

DELTA's instruments come with USB or Wi-Fi interfaces for easy data transfer. Measurement data can in a single click be passed on to a spreadsheet for further processing and generation of graphics and with GPS-installed display measurement locations and results on Google Earth.

Calibration and international standards of retroreflectometers

DELTA's instruments are all easy to calibrate, employing a simple one-step process. The calibration units are calibrated in DELTA's DANAK accredited laboratory and are traceable to Physicalish-Technische Bundesanstalt (PTB), Germany and National Institute of Standards and Technology (NIST), US.

DELTA's instruments comply with internationally recognised standards, such as EN1436, ASTM E1710, ASTM E2177, ASTM E2302 (LTL-XL) and ASTM E2832 (LTL-X) for pavement markings, and EN 20471, EN 12899, ASTM E1709 and ASTM E2540 for traffic signs and high-visibility clothing.

Contact Details

DELTA Light & Optics
Venlighedsvej 4, DK-2970 Hørsholm
+45 7219 4000
+45 7219 4630 (dir.)
+45 7219 4001

Available White Papers


Road markings: Choose the Right Type of Retroreflectometer 01 February 2017 It's well known that the visibility of road markings is important for the traffic flow and road safety. The reflection properties giving the visibility of the road marking are measured using a retroreflectometer.


Point and Annular Sign Retroreflectometers for Measuring Retroreflective Signs 11 May 2016 The following test methods apply for measurement of the retroreflective properties of sign materials such as traffic signs and symbols (vertical surfaces) using a portable retroreflectometer that can be used in the field.

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