The Dangers of Counterfeit Retro Reflective DOT C2 Truck Tape

The Hidden Hazard: The Dangers of Counterfeit DOT C2 Reflective Tape


Retro Reflective DOT tape is a critical component of road safety, enhancing visibility and reducing the risk of accidents, especially during low-light conditions. In the case of large semi trucks, the Department of Transportation (DOT) mandates specific standards for reflective tape to ensure its effectiveness in alerting motorists and preventing collisions. Unfortunately, the rise of poorly constructed counterfeit DOT tapes poses a significant threat to road safety, as these imitation products often fail to meet the required standards. In this article, we will explore the dangers associated with counterfeit DOT tape and why it’s essential to prioritize authenticity.

Reduced Visibility:

Counterfeit reflective tape typically cuts corners on the high-quality materials and engineering necessary to provide optimal visibility in low light conditions. Authentic DOT reflective tape is designed to reflect light effectively, making it visible from a considerable distance. In contrast, counterfeit DOT products may have subpar reflective capabilities, compromising a driver’s ability to identify and respond to the presence of a large truck in low-light conditions.

Shortened Lifespan:

Genuine DOT reflective tape is engineered to endure challenging weather conditions such as rain, snow, and UV exposure. In contrast, counterfeit alternatives frequently utilize subpar materials, resulting in rapid deterioration and a shortened lifespan. As the tape loses its reflective properties and adhesive strength, its ability to effectively fulfill its primary function, making large trucks conspicuous, diminishes. This decline in effectiveness increases the risk of potential collisions on the road.

Adhesive Failure:

Effective adhesion is essential for the optimal performance of DOT tapes. Films that start to lift from a surface experience accelerated deterioration compared to tape securely sealed to a surface. Counterfeit products may use substandard adhesives that fail to adhere securely to the surface, leading to peeling or complete failure. This adhesive failure compromises the tape’s functionality and poses a risk to other vehicles.

Non-compliance with Regulatory Standards:

Authentic DOT reflective tape is manufactured in accordance with strict regulatory standards to ensure consistent quality and performance. The Federal Motor Carriers Safety Administration (FMCSA) has strict requirements that these tapes must meet in order to bear the DOT C2 logo. Counterfeit products often do not meet these standards, putting users at risk of legal consequences and compromising road safety.  Not only do sub par products put other drivers at risk, they also place tremendous liability on the truck owner in the event of an accident.  The small cost savings is definitely not worth the risk.

Inferior Retroreflective Technology:

Authentic DOT reflective tape employs advanced retroreflective technology, ensuring optimal light reflection back to its source, such as a vehicle’s headlights.  Micro-prismatic films are able to alert drivers to a trucks presence from thousands of feet away in some cases. Counterfeit products may use outdated technology or substandard retroreflective materials. Consider, for example, the various counterfeit tapes that employ Type 3 High Intensity films as their base. They feature red printed block stripes, accompanied by the DOT-C2 logo, so the tape looks real.  The issue stems from the fact that Type 3 tapes deviate from FMCSA specifications, offering visibility from only a fraction of the distance that prismatic DOT tapes can achieve.  This has the potential to lead to precarious situations where motorists might struggle to promptly recognize a large vehicle or hazard, making it challenging to maneuver to safety or come to a full stop in time.


The dangers associated with counterfeit DOT C2 tape are far-reaching, encompassing reduced visibility, shortened lifespan, adhesive failure, non-compliance with regulatory standards, and inferior retroreflective technology. Prioritizing the use of authentic, regulation-compliant reflective tape is crucial to maintaining road safety and preventing accidents. Tapes such as Oralite, 3m Diamond Grade, Avery, Nikkalite, and Grote are generally recognized as good quality compliant brand name DOT tapes. It is advisable to thoroughly research non-branded tapes available on marketplaces to ensure they are not counterfeit. Buying counterfeit DOT reflective tape might seem cost-effective, but if it falls short of standards, it cannot ensure the protection of drivers. This situation can potentially place a truck driver or their company in a position of significant liability.


Reflective DOT C2 Tape Application Errors That Can Lead to Truck Accidents

Mistakes in the Application of Retro-Reflective DOT C2 Tapes That Can Lead to Avoidable Accidents

In an effort to mitigate accidents involving large commercial trucks and other vehicles, federal law mandated the application of DOT C2 red and white (silver) reflective tape to trucks in 1992. The purpose was to avoid accidents, injuries, and fatalities caused by collisions between big trucks and smaller vehicles. While the red and white tape is visible during the day, its primary function is to enhance safety and visibility at night by reflecting back the headlights of oncoming cars, providing smaller vehicles more reaction time and helping avoid potential accidents.

Tractor trailers pose specific dangers to smaller cars due to their large and relatively immovable nature, resulting in severe impacts. Additionally, the height of these trucks increases the risk of smaller vehicles going under them, making it crucial for drivers to see and stop in time.  Because of this, it is imperative that large semi trucks and trailers be marked properly and maintained.  Trucks that are below par in visibility pose a constant risk to other drivers and substantial liability to the trucks owners.

The chart below, sourced from the MUTCD, illustrates the importance of visibility in reducing accidents by demonstrating the relationship between sight distance and stopping distance. This chart is intended to show how important it is that retroreflective tapes on trucks be in good condition and placed in all the required locations. Neglect in this area places an oncoming driver closer to the truck when they become aware of its presence.

Distance Needed to Stop a Vehicle

Effectiveness of Properly Applied and Maintained DOT C2 Tape

Before discussing mistakes in applying and maintaining DOT C2 tape, we must recognize its effectiveness when properly applied and still in a new condition. An NHTSA study in 2001, eight years after the law’s implementation, found that DOT tape significantly reduced side and rear impacts into trailers, particularly in dark conditions, by up to 29%. Moreover, it proved especially effective in reducing injury crashes in low-light conditions, resulting in a 44% reduction in fatalities or injuries to drivers.

Conspicuity and Purpose of Reflective Tape

To understand these issues, it’s vital to understand that trucks are marked with bright, alternating-colored reflective tape for “conspicuity purposes,” which is defined as the property of being clearly discernible. Conspicuity goes beyond simply being visible, ensuring that an object stands out from its surroundings. Reflective tape, especially in contrasting colors, enhances conspicuity at night when it reflects light back to its source.

This article aims to highlight circumstances hindering DOT C2 reflective truck tape from fulfilling its intended purpose. Mistakes in application and maintenance of DOT tape made by trucking companies or drivers can lead to avoidable accidents, injuries, or fatalities. These errors range from tape placement to the tape’s age, condition, or type.

1. Old, Dirty, or Delaminated Tape

Tape that is delaminated or aged reflects less light than new tape. As tape ages, its reflectivity diminishes, even more so when dirt and grime accumulate on its surface. Delamination, especially in air-backed prismatic tapes, further reduces performance, allowing water, dirt, and grime to compromise the tape’s reflective properties.

dirty damaged dot c2 retro reflective tape

2. Tape Placed Too High on a Truck

Since automobile headlights are designed to shine low to avoid blinding other drivers, DOT tape must be placed as low as possible. Proper placement ensures maximum reflectivity and visibility. Tape applied too high, especially on the side of a tanker, might go unnoticed by approaching drivers, potentially leading to collisions. The DOT requirement is from 15 – 60 inches above the road.  Note that the truck in the picture below is not in violation.

dot c2 retro reflective tape placed too high

3. Tape Placed at an Angle Versus a Proper Vertical Application

DOT C2 tape reflects best when perpendicular to a light source. Placing the tape at an angle reduces its efficiency, resulting in lower reflectivity percentages. For instance, a tape at a 30-degree angle may lose up to 40% reflectivity for the white portion, affecting its visibility and effectiveness in preventing accidents.  This means that with a lower return of light, oncoming vehicles need to be closer to the truck to see the reflective tape.

dot c2 reflective tape installed at angle

4. Counterfeit DOT Tape

The market offers cheaper DOT tapes made in other countries, but many of these are counterfeit and not compliant with NHTSA/FMCSA requirements. Non-compliant tape may not meet photometric requirements, compromising its ability to reflect enough light for proper conspicuity. This can lead to late detection by approaching drivers, increasing the risk of accidents.

counterfeit retro reflective dot c2

5. Skipped Area of a Truck

Skipping certain areas of a truck during tape application, believing enough tape has been applied, leaves those areas vulnerable to accidents. All areas required by law should be marked to ensure comprehensive visibility. Failure to do so creates unnecessary hazards, especially in critical areas like the under-ride bar. Remember, at night, the reflective tape is often all an approaching driver sees.

missing dot c2 retro reflective tape

Going Above and Beyond Minimum Requirements

While many trucking companies adhere to minimum requirements for reflective safety, going beyond these can enhance visibility, improve safety, and show due diligence in the event there is an accident. Options include using wider certified tapes, placing tape in lower areas or under the truck box, incorporating reflective graphics, or outlining the truck silhouette with reflective tape.

In conclusion, addressing these oversights in the application of retro-reflective DOT C2 tapes is crucial for maximizing their effectiveness in preventing accidents and ensuring the safety of all drivers on the road. Understanding the impact of tape placement, condition, and compliance with regulations is key to maintaining optimal conspicuity and reducing the risk of collisions.


Definitions – Glossary of Retro Reflective Terms

Glossary (Definitions) of Terms Related to Retro-Reflectivity and Photo-Metrics 

In order to assist our customers in understanding all aspects of visibility, photo-metrics, and retro-reflectivity, we have put together a glossary of relevant terms.  Words that you will see in specification sheets, regulations, and accident analysis reports.  This list will hopefully help you with clarity as you read through these documents.

Adhesive (for retro reflective sheeting) – A sticky substance that is used to join two things together.  This is normally permanent, but can also be temporary (removable).  For retro reflective tape there are 5 classes of adhesive backings.  Each is for a specific purpose.  Class 1 is the most common and is the backing found on most reflective tapes.

ASTM D4956 Type 1 through 11 – This specification includes flexible, non-exposed glass-bead lens and microprismatic, retroreflective sheeting for traffic control signs, delineators, road barrels, and devices. ASTM 4956 does not address inks, overlays, or other printing methods that may be applied to retroreflective sheeting material to create traffic signs or other devices.

ASTM E810 – A standardized method for measuring retro reflectivity. Measurements made by this test method are related to visual observations of retroreflective sheeting as seen by the human eye when illuminated by tungsten-filament light sources such as a motor vehicle headlamp.

Brightness – Attribute of a visual perception according to which an area appears to emit more or less light. The quality or state of giving out or reflecting light.  The opposite of darkness.  One object being substantially brighter than another, creates contrast and conspicuity.

Candelas / Lux / Square Meter – A unit of luminous intensity expressed as one candela in one second of light emittance per square meter of area.  This is the unit of measurement used to measure the intensity of brightness of retroreflective sheeting and other lighting.  This measurement is also used to set minimum standards for reflectivity.

Chromaticity – Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness.  It is the quantification of color.

Chromaticity Coordinates – A numeric description of color.  Or color quantified with numeric coordinates. The chromaticity coordinates can be expressed on a 2D chromaticity diagram.  These coordinates assure that a retro reflective tape is the proper color.

Chromaticity Diagram – This diagram shows all the hues perceivable by the standard observer for various (x,y) pairs and also indicates the spectral wavelengths of the dominant single frequency colors.  It is an image that displays all colors and their corresponding xy coordinate.

Coefficient of Retro-Reflection – The ratio of the coefficient of luminous intensity of a plane retroreflecting surface to its area expressed in candelas per square meter.

Color – The aspect of any object that may be described in terms of hue, lightness, and saturation.  Expressed by chromaticity coordinates according to the CIE (Commission Internationale de l’Eclairage 1931 ) standard colorimetric system.

Competitive Lighting – Lighting that overshadows or drowns out other lights or retro reflective surfaces to where they become less conspicuous or invisible.  An example would be a trucks headlights shining at 15,000 candelas, near retro reflective tape shining at 500 candelas.

Cone of Retro Reflectivity – light returning from a sheet of reflective tape expands as it moves towards the light source.  As it expands, it forms a cone of reflectivity shaped like a megaphone.  As the light expands, it becomes dimmer.

Conspicuity – the characteristics of an object that determine the likelihood that it will come to the attention of an observer.   This is achieved through color, contrast, patterns, and brightness.

Department of Transportation (US-DOT) – The federal agency in charge of all transportation related affairs in the US. This agency is over the FMCSA (Federal Motor Carrier Safety Association), NHTSA (National Highway Traffic Safety Association), FHWA (Federal Highway Association), and many other transportation agencies. (FAA, FTA, FRA, MARAD, PHMSA, etc.)

Diffused or Scattered Reflectivity – light is scattered or diffused in multiple directions.   Almost all objects are seen in this way.  If you look at your car in daylight, you are seeing it because of diffused or specular reflectivity.

Dimensional Stability – in terms of retro reflective tape or any other adhesive film, this is the ability of a film to hold its original size.  The more dimensionally stable a film is, the longer it lasts on a surface, given good adhesion.

Entrance angle – angle between the illumination axis and the retroreflector axis. This is the angle that light enters a retro reflective film.  At a perpendicular 0 degree angle, reflectivity is at its highest.  Specification sheets measure maximum reflectivity at 4 degrees entrance angle.  At a 15 degree entrance angle, retro reflectivity is reduced by approximately 20%.  At 30 degrees, reflectivity drops by approximately 50%.  At 45 degrees, reflectivity drops by approximately 85%.  And at a 60 degree entrance angle, retro reflectivity is reduced by 86 – 99% depending on the tape type and brand.

Federal Motor Carrier Safety Administration (FMCAS) – established within the Department of Transportation on January 1, 2000, pursuant to the Motor Carrier Safety Improvement Act of 1999 [Public Law No. 106-159, 113 Stat. 1748 (December 9, 1999)]. Formerly a part of the Federal Highway Administration, the Federal Motor Carrier Safety Administration’s primary mission is to prevent commercial motor vehicle-related fatalities and injuries. (this agency is under the US DOT)

Flexibility – the ability of an object or film to stretch, conform, or bend.  The quality of bending easily without breaking.

Glass Bead Reflective Sheeting (tape) – retro reflective films that use perfectly round glass sphere for reflectivity.  Light enters the bead, is bent, bounced and returned to the light source.  There are two kinds of beads, standard and metallized.  Glass bead reflective tape is not as bright as prismatic films.

Impact Resistance – the ability of a material to resist permanent deformation caused by high force or shock applied to it over an extremely short period of time.

Light Dispersion – the width of the returning beam of light from a standard or  reflective surface. Certain tapes reflect in a tight beam and can be seen at great distances. Others reflect in a wider beam and can be seen closer in but at wider angles.

Luminance Factor – the ratio of the luminance of the body considered to the luminance of a perfect diffuser under identical conditions of illumination and observation.

Micro-Prismatic Reflective Sheeting (tape) – retro reflective tape that achieves reflectivity via man made micro prisms.  A prism array is embossed on the back of a film and either metalized like a mirror, or backed with a white film.  Prismatic retro reflective tape is brighter than glass bead films.

National Highway Traffic Safety Administration (NHTSA)  – responsible for reducing deaths, injuries and economic losses resulting from motor vehicle crashes. NHTSA sets and enforces safety performance standards for motor vehicles and equipment, and through grants to state and local governments enables them to conduct effective local highway safety programs. NHTSA investigates safety defects in motor vehicles, sets and enforces fuel economy standards, helps states and local communities reduce the threat of drunk drivers, promotes the use of safety belts, child safety seats and air bags, investigates odometer fraud, establishes and enforces vehicle anti-theft regulations and provides consumer information on motor vehicle safety topics. (this agency is under the US DOT)

Observation angle – angle between the axes of the incident beam and the observed (reflected ) beam. In retroreflection the angle between the illumination axis and the observation axis.

Photometer – an instrument for measuring light.  Often used in photography.  These devices do not necessarily measure retro reflectivity, just basic light returning from a surface in daylight.

Photometrics – The study of light.  The measurement of the intensity, brightness, chromaticity, or other properties of light.

Retro Reflectivity – the ability of a surface to return light back to the light source.  This differs from scattered or diffused reflectivity which is when a surface returns light in all directions, and specular reflectivity which is like a mirror. (AKA – Retro Reflection – reflection in which the reflected rays are preferentially returned in directions close to the opposite of the direction of the incident rays, this property being maintained over wide variations of the direction of the incident rays.)

Refraction – change in the direction of the propagation of radiation determined by change in the velocity of the propagation in passing from one medium to another.

Retro-Reflective Element – A single optical unit which by refraction or reflection, or both, produces the phenomenon of retroreflection.

Retro-Reflective Material – A material that has a thin continuous layer of small retroreflective elements on or very near its exposed surface ( for example, retroreflective sheeting, beaded paint, highway sign surfaces or pavement striping).

Retro-Reflective sheeting – A retro-reflective material preassembled as a thin film ready for use.

Retroreflectometer – In the most simple of terms a retroreflectometer is an instrument that assesses the nighttime visibility of a retro reflective surface.  Reflective surfaces such as sign faces, DOT C2 tape, and pavement markings, can be tested.  The readings from these devices are in candelas, which is a measure of light.  The devices are first calibrated using a known reading from a sample swatch of retro reflective material, and then used to test the subject film.

Retro-Reflector – A surface or device that reflects light back along the incident path, irrespective of the angle of incidence.  This simply means that it returns light back to the source.  These devices can normally accomplish this at angles of up to 60 degrees, with reflectivity declining as the angle increases.

Rotation Angles – An angle of rotation is the measure of the amount that a figure is rotated about a fixed point called a point of rotation. Reflective tape brightness is measured at different rotation angles.

Shrinkage – the reduction in size of a film compared to its original size.  In terms of tape, it is how much the film pulls back over time.  This process can affect the longevity of a film.  A lack of shrinkage is called dimensional stability.

Sight Distance – Sight Distance is a length of road surface which a particular driver can see with an acceptable level of clarity.

Solvent Resistance – the ability of a surface to resist corrosion or degradation from solvents such as alcohol, mineral spirits, etc..  The more solvent resistant a surface is, the longer it lasts in a harsh environment.  Generally speaking.

Specular Gloss – the measure of light reflecting off of the surface of an object or film.  A polished surface has more gloss than a matte surface.

Specular Reflectivity – Mirror like reflectivity.  Light return depends on the angle of the surface.

Source – An object that produces light or other radiant flux, such as a vehicles headlights.

Stopping Sight Distance – Stopping Sight Distance (SSD) is the viewable distance required for a driver to see so that he or she can make a complete stop in the event of an unforeseen hazard.

Viewing angle – The angle between the retroreflector axis and the observation axis.  The angle in which we view an object.

Visibility – The properties and behavior of light waves and objects interacting in the visual environment to produce light signals capable of evoking visual sensation.


How We Review Retro Reflectivity as it Relates to a Truck or Vehicle Accident

As it pertains to retro reflective tape, there are several factors that we consider when reviewing an accident between a large semi-truck and another vehicle.  Our goal in assessing these elements is to estimate what an approaching vehicle most likely saw as they neared the truck in question.  This can be compared and contrasted with a properly marked truck.

These elements are as follows –

Properly Applied Certified Retro Reflective DOT C2 Tape – It important that certified reflective DOT tape with the DOT-C2 logo be affixed to a semi truck and the trailer it tows, in the right amounts, and in the proper places.  Failure to do this violates Federal Regulation and places the lives of other drivers in danger.  In dark conditions, the retro reflective tape on a truck may be the only thing that alerts a driver to a trucks presence. With this being said, the Federal Motor Carriers Safety Administration (FMCSA) and the National Highway Traffic Safety Administration (NHTSA) mandate that trucks over 80 inches wide and over 10,000 pounds be marked with DOT-C2 C3 or C4 retro reflective tape.  (the C2 C3 C4 are the widths of the tape)  Specific requirements are in our FMCSA article here.

To be certified, DOT tapes must meet certain requirements.  These are color (chromaticity), surface appearance, width, pattern spacing, DOT-C2 logo, and retro reflective performance.  Generally speaking, the regulation requires DOT tape to meet ASTM D4956 Type 5 specifications for all aspects of the film except for photo metrics.  For photo-metrics, which in this case is brightness, the FMCSA provides a chart, however, it is roughly the equivalent of ASTM D4956 Type 3 requirements.

The amount of tape to be applied and where it must be applied are also specifically outlined in the Federal regulation.  These areas are the sides of the trailer, the back lower areas, the back upper areas, and the truck itself (cab).  All areas specified must be marked with DOT approved retro reflective tape that is a minimum of 2 inches wide, up to 4 inches.  Damaged tape that no longer meets DOT specs may cause a truck to fail inspection.

retro reflective dot c2 conspicuity chart diagram
DOT Retro Reflective Tape Placement Requirements

Condition of the DOT C2 Retro Reflective Tape –  Damaged or missing retro reflective DOT C2 tape can affect the ability of other drivers to see a large truck at night.  Tape age, weathering, dirt, and grime also contribute to a less effective reflective tape performance.  Missing tape is often caught by DOT inspectors, but weathered, aged, or dirty tape are seldom used as grounds for an inspection failure since inspectors do not normally run retro reflectivity tests on the tape.  But just because a truck did not fail an inspection, does not mean that the retro reflective tape on that truck is performing to minimum specifications.

In reference to age, DOT tape manufacturers warranty their tapes meet minimum FMCSA and NHTSA standards for 5 , 7 , or 10 years depending on the brand and model.  And this warranty applies only if the tape is properly applied and cared for.  After the warranty period expires, manufacturers no longer guarantee that the tape will meet minimum reflectivity requirements, which is the most important characteristic of the tape when it comes to sight distance.  This means that it is possible that older tapes that are beyond their warranty no longer meet minimum reflectivity standards, and as such, no longer provide the necessary protection from collisions.

The issue with degraded tape is that as reflectivity decreases, the distance at which the tape can be seen decreases as well.  So at some point, by the time a driver sees the tape, it is too late to stop, and a collision occurs.

Old damaged dot c2 retro reflective conspicuity tape
Example of Old DOT C2 tape with Diminished Reflectivity

Ambient Lighting at the Time of the Accident –  Since light creates what our eyes see, it is very important to know how much light was present at the scene of an accident, at the exact time that it occurred.  Was it day or night?  Was the moon full?  Were there street lights nearby?  Or was it completely dark?  This analysis is important because the less ambient light there is lighting up a truck, the more approaching drivers must depend on other conspicuity that is affixed to the truck itself.  At night, with very little or no ambient lighting, approaching drivers depend solely on the large truck and trailers lights, and the retro reflective conspicuity tape attached to the truck itself.  At night, without these two elements, or if they are substantially diminished, trucks can easily be invisible to an approaching driver.

Weather Conditions at the Time of the Accident – Rain, Snow, Fog, or Smoke in the area of an accident can affect visibility.   Any one of these elements can greatly affect what an approaching driver sees as he nears a large semi truck.  Darkness, and the addition of one or more of these elements can make perceiving objects in the distance difficult for a driver.  In situations like this, effective truck lights, and bright retro reflective tape in very good condition would be necessary to cut through these elements and alert an approaching driver of the presence of a semi truck.  In inclement conditions, even a moderately degraded film may not be enough to provide conspicuity, and as such, it is entirely possible that a large truck may appear invisible to an approaching driver.

 Angle of the Retro Reflective Tape in Relation to the Oncoming Driver (Entrance Angle of Light) – Retro Reflective Tapes perform at their maximum when they are perpendicular to a cars headlights.  As that angle increases, and light from a cars headlights strike the tape at more and more of an angle, reflectivity decreases.  At some point above the 45 degree mark, the tape no longer returns sufficient light to be seen from a distance.  This angle can be created from a truck sitting at an angle across a roadway, or from the tape being applied at an angle on the truck.  More often the issue is the overall angle of the truck.  So if a truck is parked across a roadway at a 60 degree angle, an approaching vehicle may not see the retro reflective tape at all, even when close in.  So if at night, a truck driver places his trailer at a sharp angle to approaching traffic, the chances of a collision are high since that sharp of an entrance angle renders reflective tape almost invisible.

entrance angle retro reflectivity example
The Highest Level of Retro Reflectivity is at 0 Degree Entrance Angle.

Height of the Installed Retro Reflective Tape in Comparison to the Approaching Vehicles Headlights –  The height DOT C2 retro reflective tape is applied is important.  As stated in Federal Regulation, DOT C2 tape applied to the side of a truck should fall between 15 and 60 inches from the road surface.  The main issue is height.  Tape placed too high on a truck can result in car headlights (low beams) hitting below the tape.  This is especially true with newer cars with a tight beam pattern.  If a cars headlights hit below the conspicuity tape, very little light is returned to the driver, rendering the truck difficult for the driver to see.  Generally, the lower that a tape can be installed on the sides of a truck, the better for visibility.

Competitive Lighting at the Accident Scene – At night, light coming from headlights, running lights, street lights, and other sources, compete with retro reflective tape for the attention of drivers.  For example, if a section of Retro Reflective DOT tape, that reflects at 700 candelas, is near headlights that emit 15,000 to 20,000 candelas, it is easily drowned out.  And if attention is drawn to the headlights of a truck, and its trailer is in the path of the oncoming vehicle, an accident can easily occur.

Observation Angle of Oncoming Driver To Returning Light –  The distance that a drivers eyes are from their own headlights constitutes what is known as the observation angle.   Light from headlights is directed at retro reflective tape and is bounced back to the source of the light which is the headlights.  In a standard vehicle, the eyes of the driver are only slightly above the returning light.  In a truck however, the eyes of the driver are higher.  The typical observation angle for the driver of a car is .20 degrees, and the observation angle for a truck driver is .50 degrees.  This difference in observation angles reduces the return of light to a drivers eyes by a surprising 77%.

observation angle truck accident expert report

Distance Away and Speed of Approaching Driver – If an accident occurred due to a large truck pulling into or across traffic, it is important to know how many feet away the approaching vehicle was from the impact point and how fast the driver was traveling at that point in time.  This information, along with an analysis of the retro reflective tape on the truck allows an assessment to be made as to how much time the driver had to identify the truck and take evasive action, and how many feet they had to do so.   Combining this data with information about the condition of the retro reflective tape affixed to the truck allows us to make assumptions about what the driver saw, when they saw it, and how much time they had to react.

Distance Needed to Stop a Vehicle


DOT C2 C3 C4 Retro Reflective Conspicuity Tape – Standards to be Certified

What standards must a retro reflective tape must meet to be certified?

The standards and specifications for DOT tape to be certified are required by Federal Regulation § 393.11, through its cross reference to FMVSS No. 108.  I have included some definitions below which include agencies involved in the regulation of over the road trucks.  There are quite a few and what each does can be a bit confusing.  Also add to this that each state has its own Department of Transportation with rules and regulation.

The information and regulations below cover the color and pattern of the films that can be used as DOT tape, as well as the required photometrics.  Also covered in the text below is the required placement of the DOT tape on the truck and trailer.  For placement, this article is more clear and concise.

Definitions –

FMVSS – Federal Motor Vehicle Safety Standards

NHTSA – National Highway Traffic Safety Administration

FMCSA – Federal Motor Carrier Safety Administration

DOT – US Department of Transportation

Retro Reflectivity – the ability of an object to reflect light back to its source.

Conspicuity – something being highly visible or conspicuous.  The process of making something more visible.

Photometry (photometrics) – science that deals with the measurement and intensity of light.

Certification – the process of assuring something meets certain standards.

Retro-reflector – a device used to indicate the presence of a vehicle by the reflection of light emanating from a light source not connected to the vehicle (similar to retro reflective sheeting)


§ 393.11 Lamps and reflective devices.

(1) Lamps and reflex reflectors. Table 1 specifies the requirements for lamps, reflective devices and associated equipment by the type of commercial motor vehicle. The diagrams in this section illustrate the position of the lamps, reflective devices and associated equipment specified in Table 1. All commercial motor vehicles manufactured on or after December 25, 1968, must, at a minimum, meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture of the vehicle. Commercial motor vehicles manufactured before December 25, 1968, must, at a minimum, meet the requirements of subpart B of part 393 in effect at the time of manufacture.

(2) Exceptions: Pole trailers and trailer converter dollies must meet the part 393 requirements for lamps, reflective devices and electrical equipment in effect at the time of manufacture. Trailers which are equipped with conspicuity material which meets the requirements of § 393.11(b) are not required to be equipped with the reflex reflectors listed in Table 1 if—

(i) The conspicuity material is placed at the locations where reflex reflectors are required by Table 1; and

(ii) The conspicuity material when installed on the motor vehicle meets the visibility requirements for the reflex reflectors.

(b) Conspicuity Systems. Each trailer of 2,032 mm (80 inches) or more overall width, and with a GVWR over 4,536 kg (10,000 pounds), manufactured on or after December 1, 1993, except pole trailers and trailers designed exclusively for living or office use, shall be equipped with either retroreflective sheeting that meets the requirements of FMVSS No. 108 (S5.7.1), reflex reflectors that meet the requirements FMVSS No. 108 (S5.7.2), or a combination of retroreflective sheeting and reflex reflectors that meet the requirements of FMVSS No. 108 (S5.7.3). The conspicuity system shall be installed and located as specified in FMVSS No. 108 [S5.7.1.4 (for retroreflective sheeting), S5.7.2.2 (for reflex reflectors), S5.7.3 (for a combination of sheeting and reflectors)] and have certification and markings as required by S5.7.1.5 (for retroreflective tape) and S5.7.2.3 (for reflex reflectors).

Federal Motor Vehicle Safety Standards (FMVSS) – Title 49 / Sub Title B / Chapter 5 / Part 571 / Sub Part B / 571.108 – Conspicuity Systems

(§ 571.108 Standard No. 108; Lamps, reflective devices, and associated equipment.)

S8.2 Conspicuity systems. The requirement for conspicuity systems may be met with retroreflective sheeting, conspicuity reflex reflectors, or a combination of retroreflective sheeting and conspicuity reflex reflectors.

S8.2.1 Retroreflective sheeting.

S8.2.1.1 Retroreflective sheeting must consist of a smooth, flat, transparent exterior film with retroreflective elements embedded or suspended beneath the film so as to form a non-exposed retroreflective optical system.

S8.2.1.2 Retroreflective sheeting material. Retroreflective sheeting must meet the requirements, except photometry, of ASTM D 4956–90 (incorporated by reference, see § 571.5) for Type V Sheeting. Sheeting of Grade DOT–C2 of no less than 50 mm wide, Grade DOT–C3 of no less than 75 mm wide, or Grade DOT–C4 of no less than 100 mm wide may be used.

S8.2.1.3 Certification marking. The letters DOT–C2, DOT–C3, or DOT–C4, as appropriate, constituting a certification that the retroreflective sheeting conforms to the requirements of this standard, must appear at least once on the exposed surface of each white or red segment of retroreflective sheeting, and at least once every 300 mm on retroreflective sheeting that is white only. The characters must be not less than 3 mm high, and must be permanently stamped, etched, molded, or printed in indelible ink.

S8.2.1.4 Application pattern.

S8. Alternating red and white materials.

S8. As shown in Figures 12–1 and 12–2, where alternating material is installed, except for a segment that is trimmed to clear obstructions, or lengthened to provide red sheeting near red lamps, alternating material must be installed with each white and red segment having a length of 300 ±150 mm.

S8. Neither white nor red sheeting must represent more than two thirds the aggregate of any continuous strip marking the width of a trailer, or any continuous or broken strip marking its length.

S8.2.1.5 Application location. Conspicuity systems need not be installed, as illustrated in Figure 12–2, on discontinuous surfaces such as outside ribs, stake post pickets on platform trailers, and external protruding beams, or to items of equipment such as door hinges and lamp bodies on trailers and body joints, stiffening beads, drip rails, and rolled surfaces on truck tractors.

S8.2.1.6 Application spacing. As illustrated in Figure 12–2, the edge of any white sheeting must not be located closer than 75 mm to the edge of the luminous lens area of any red or amber lamp that is required by this standard. The edge of any red sheeting must not be located closer than 75 mm to the edge of the luminous lens area of any amber lamp that is required by this standard.

S8.2.1.7 Photometry. Each retroreflective sheeting must be designed to conform to the photometry requirements of Table XVI–c when tested according to the procedure of S14.2.3 for the color and grade as specified by this section.

S8.2.2 Conspicuity reflex reflectors.

S8.2.2.1 Certification marking. The exposed surface of each conspicuity reflex reflector must be marked with the letters DOT–C which constitutes a certification that the reflector conforms to the conspicuity reflex reflector requirements of this standard. The certification must be not less than 3 mm high, and must be permanently stamped, etched, molded, or printed in indelible ink.

S8.2.2.2 Application pattern.

S8. Alternating red and white materials. Conspicuity reflex reflectors must be installed in a repetitive pattern of two or three white reflectors alternating with two or three red reflectors, with the center of each reflector not more than 100 mm from the center of each adjacent reflector.

S8. White material. White conspicuity reflex reflectors must be installed with the center of each reflector not more than 100 mm from the center of each adjacent reflector.

S8.2.2.3 Photometry. – see also chart at bottom of this page for photometrics

dot c2 c3 c3 fmvss photometry requirements

S8. Each red conspicuity reflex reflector must be designed to conform to the photometry requirements of Table XVI–a for a red reflex reflector and Table XVI–b for a red conspicuity reflex reflector when tested according to the procedure of S14.2.3 as specified by this section.

S8. Each white conspicuity reflex reflector installed in only a horizontal orientation must be designed to conform to the photometry requirements of Table XVI–a for a white reflex reflector and Table XVI–b for a white horizontal conspicuity reflex reflector when tested according to the procedure of S14.2.3 as specified by this section.

S8. Each white conspicuity reflex reflector installed in a vertical orientation must be designed to conform to the photometry requirements of Table XVI–a for a white reflex reflector, and Table XVI–b for a white horizontal conspicuity reflex reflector and a white vertical conspicuity reflex reflector when tested according to the procedure of S14.2.3 as specified by this section.

S8.2.3 Conspicuity system installation on trailers.

S8.2.3.1 Trailer rear.

S8. Element 1—alternating red and white materials. As shown in Figure 11, a strip of sheeting or conspicuity reflex reflectors, as horizontal as practicable, must be applied across the full width of the trailer, as close to the extreme edges as practicable, and as close as practicable to not less than 375 mm and not more than 1525 mm above the road surface at the strip centerline with the trailer at curb weight.

S8. Element 2—white. (not required for container chassis or for platform trailers without bulkheads).

S8. As shown in Figure 11, two pairs of strips of sheeting or conspicuity reflex reflectors, each pair consisting of strips 300 mm long of Grade DOT–C2, DOT–C3, or DOT–C4, must be applied horizontally and vertically to the right and left upper contours of the body, as viewed from the rear, as close to the top of the trailer and as far apart as practicable.

S8. If the perimeter of the body, as viewed from the rear, is other than rectangular, the strips may be applied along the perimeter, as close as practicable to the uppermost and outermost areas of the rear of the body on the left and right sides.

S8. Element 3—alternating red and white materials. (not required for trailers without underride protection devices).

S8. As shown in Figure 11, a strip of Grade DOT–C2 sheeting no less than 38 mm wide or reflectors must be applied across the full width of the horizontal member of the rear underride protection device.

S8.2.3.2 Trailer side—alternating red and white materials.

S8. As shown in Figure 11, a strip of sheeting or conspicuity reflex reflectors must be applied to each side, as horizontal as practicable, originating and terminating as close to the front and rear as practicable, as close as practicable to not less than 375 mm and not more than 1525 mm above the road surface at the strip centerline at curb weight, except that at the location chosen the strip must not be obscured in whole or in part by other motor vehicle equipment or trailer cargo.

S8. The strip need not be continuous as long as not less than half the length of the trailer is covered and the spaces are distributed as evenly as practicable.

S8. If necessary to clear rivet heads or other similar obstructions, Grade DOT–C2 sheeting may be separated into two 25 mm wide strips of the same length and color, separated by a space of not more than 25 mm and used in place of the retroreflective sheeting that would otherwise be applied.

S8.2.4 Conspicuity system installation on truck tractors.

S8.2.4.1 Element 1—alternating red and white materials. As shown in Figure 13, two strips of sheeting or conspicuity reflex reflectors, each not less than 600 mm long, located as close as practicable to the edges of the rear fenders, mudflaps, or the mudflap support brackets, must be applied to mark the width of the truck tractor.

S8. The strips must be mounted as horizontal as practicable, in a vertical plane facing the rear, on the rear fenders, on the mudflap support brackets, on plates attached to the mudflap support brackets, or on the mudflaps.

S8. Strips on mudflaps must be mounted not lower than 300 mm below the upper horizontal edge of the mudflap. If the vehicle is certified with temporary mudflap support brackets, the strips must be mounted on the mudflaps or on plates transferable to permanent mudflap support brackets.

S8. For a truck tractor without mudflaps, the strips may be mounted outboard of the frame on brackets behind the rear axle or on brackets ahead of the rear axle and above the top of the rear tires at unladen vehicle height, or they may be mounted directly or indirectly to the back of the cab as close to the outer edges as practicable, above the top of the tires, and not more than 1525 mm above the road surface at unladen vehicle height.

S8. If the strips are mounted on the back of the cab, no more than 25% of their cumulative area may be obscured by vehicle equipment as determined in a rear orthogonal view.

S8.2.4.2 Element 2—white. As shown in Figure 13, two pairs of strips of sheeting or conspicuity reflex reflectors, each pair consisting of strips 300 mm long, must be applied horizontally and vertically as practicable to the right and left upper contours of the cab, as close to the top of the cab and as far apart as practicable.

S8. No more than 25% of their cumulative area may be obscured by vehicle equipment as determined in a rear orthogonal view.

S8. If one pair must be relocated to avoid obscuration by vehicle equipment, the other pair may be relocated in order to be mounted symmetrically.

S8. If the rear window is so large as to occupy all the practicable space, the material may be attached to the edge of the window itself.

S14.2.3 Reflex reflector and retroreflective sheeting photometry.

S14. Retroreflective sheeting. The required measurement for retroreflective sheeting reflectors at each test point as shown in Table XVI is candela per lux per square meter of area.

S14.2.3.7 Procedure. Photometric measurements of reflex reflectors and retroreflective sheeting must be made at various observation and entrance angles as shown in Table XVI.

federal regulations for dot c2 c3 c4 retro reflective tape



NHTSA Report on the Effectiveness of DOT C2 Retro Reflective Tape on Tractor Trailers

In 2001, after all trucks had either been manufactured with retro reflective DOT C2 tape that met NHTSA specifications, or had been retro-fitted, the agency conducted a study of the reflective tapes effectiveness in preventing accidents.

It was found that by treating a truck and trailer with DOT C2 with the minimum required retro reflective DOT C2 (2″ wide), in accordance with the regulation, accidents at night were reduced by 44%. (up to 5000 injuries and 350 fatalities prevented) The report, quoted below, covers a variety of important subjects and discusses the difficulty of night time visibility when it comes to the large on the road trucks and trailers.

Keep in mind that 2″ wide DOT C2 tape is the minimum standard.  But C3 and C4 (3″ and 4″ wide) tapes are also available and would provide even more night time conspicuity, hence decreasing accidents. (see DOT C2 FMCSA regulation)

The full study performed by the NHTSA is below.


FRA 224 Train Retro Reflective Marking Requirements (Regulation)

Trains and freight cars pose a great danger to passenger vehicles, should the two ever come in contact with each other.  Tractor trailer rigs are large, heavy and immovable, but freight cars are more so.  To reduce the incidences of train and passenger car collisions, the Federal Rail Association passed FRA 224, a regulation that requires all rail stock be clearly marked with retro reflective strips at specific intervals.  The regulation is posted below.


FMCSA’s Conspicuity Requirements for Commercial Motor Vehicles

You will find below the FMCSA (Federal Motor Carrier Safety Administration) regulation for marking DOT regulated trucks and trailers.  This regulation was passed by the NHTSA (National Highway Traffic Safety Association) in December of 1992 and is applicable to all trucks with a gross vehicle weight of 10,000 pounds and an overall width of 80 inches.  The purpose of this regulation is reduce the number of collisions between large trucks and passenger vehicles.  In 2001, the effectiveness of this regulation was analyzed and a report was prepared by the NHTSA showing a decrease in accidents of 44% for trucks and trailers properly treated with retro reflective tape.


Retro Reflectivity and DOT Regulated Trucks – Summary

Tractor-trailer rigs, among the largest vehicles on American highways, pose significant risks to smaller vehicles. Annually, collisions involving these large trucks lead to around 120,000 injuries and over 5,000 deaths in the United States. Due to their massive and solid structure, tractor-trailers are particularly unforgiving in accidents with smaller vehicles, often resulting in severe outcomes.

Contrary to what one might expect, the substantial size of these trucks doesn’t always aid in visibility. In many driving scenarios, their large trailers can blend into the surroundings, becoming virtually invisible to approaching drivers. This effect is similar to how the outer edges of an IMAX screen can vanish from a viewer’s peripheral vision. The situation is further complicated by competing lights from the truck and other vehicles, especially problematic at night when the trailer towed by a truck often remains unseen until its headlight pass by.

History of the Application of Reflective Tape to Trucks
Nighttime visibility has always been a key component in accidents involving large trucks. The core problem is that drivers often fail to notice these large trucks in time to prevent a collision, especially in low-light conditions. In modern times, the most significant visibility issues arise from the use of either insufficient or poorly maintained reflective tape on trucks.

However, prior to 1992, the situation was more critical as there was no mandate for trucks to use retroreflective tape. Without this tape, trucks were even harder to spot at night, increasing the risk of accidents. The absence of mandatory retroreflective tape meant that many trucks blended into the dark surroundings, making them virtually invisible to other road users until it was too late to avoid a collision. The introduction of regulations requiring reflective tape on trucks was a significant step towards improving nighttime visibility and reducing accidents.

To address this, the NHTSA implemented a regulation in December 1992, mandating the use of retroreflective tape in specific locations on DOT-regulated trucks. By June 2001, all trucks were required to have this tape, and by June 2009, uniformity in truck markings was achieved. The minimum standard is DOT C2 tape, which is 2 inches wide, but wider options like DOT C3 and C4 tapes are also permitted and offer increased visibility.

A 2001 NHTSA study confirmed the effectiveness of this regulation, finding a 44% reduction in nighttime accidents involving trucks with the required retroreflective tape. This measure is estimated to prevent up to 5,000 injuries and 350 fatalities each year, demonstrating its efficacy.

However, issues persist with trucks that either lack sufficient markings as per DOT standards or use old, UV-damaged, and weathered tape, which compromises visibility and heightens accident risks. It’s vital to maintain proper markings with fresh, certified high-quality branded tape to enhance visibility and allow other drivers adequate time to spot and avoid trucks.

Interestingly, FMCSA regulations specify that trucks can use DOT retroreflective tape ranging from 2 inches (C2) to 4 inches (C4) in width. While all three sizes are available, 4-inch tape offers double the reflectivity and visibility. Despite this, 99% of trucks on the road use the minimum C2 tape.