DOT Truck (Tractor Trailer) marking requirements were set up by the FMCSA to help improve visibility in low light conditions and reduce the probability of fatal motor vehicle crashes into the sides or back of stopped or parked trucks and tractor trailers at night or in poor visibility conditions.
On December 10, 1992, the National Highway Traffic Safety Administration or NHTSA published a final ruling that required trailers manufactured on or after December 1, 1993 having an overall width of 80 inches or more and a gross vehicle weight rating (GVWR) of more than 10,000 pounds, be equipped on the sides and rear with a means for making them more visible on the road. The NHTSA ruling allows trailer manufacturers to install either red and white retro reflective tape or sheeting or reflex reflectors. This tape is commonly referred to as DOT-C2 reflective tape and is thus marked for easy identification (Exemption – pole trailers and trailers designed exclusively for living or office use)
While the term DOT C2 Red and White Reflective Tape is used quite often in regards to marking tractor trailer rigs 80 inches wide or wider and over 10,000 lbs GVWR, what the term “DOT C2” means is seldom discussed. Most people know that the letters DOT mean “Department of Transportation. Also, some people know that the term C2, C3 or C4 refers to the width of the tape. (2″,3″ or 4”) Most people do not know what it takes for a reflective tape to be certified as “DOT C2, C3, or C4”. This article is meant to help you understand what these requirements are so that you can be sure that you are using the correct product on your vehicle. In the event of an accident, having the proper markings is especially important. We recommend Oralite (formerly Reflexite) DOT tapes. They invented prismatic reflective tape and their products are respected and recognized around the world. The downsides to using a cheap substitute are simply not worth it.
In order to be certified as DOT C2, C3 or C4 tape, certain requirements have to be met. These requirements involve the construction of the tape, the color, the width, the spacing of the alternating colors, the performance, and the reflectivity. If a DOT C2 Red Reflective Tape has been certified to meet these standards then the manufacturer is allowed to put DOT C2 certification on it. The specifics of the requirements are as follows. (Source – Federal Motor Carrier Safety Administration 393.11)
Color – DOT tape must be made with white and red alternating colors. The white color on prismatic tapes often looks silver but reflects white at night.