Tractor-trailers operate as a part of either domestic or international transport infrastructures to support containerized cargo shipments. With millions of tractor-trailers on the road, blind spot areas are in abundance and threaten the safety of all drivers who share the road.
Generally speaking, larger vehicles have larger rear blind spots. The blind spot behind tractor-trailers can contain entire vehicles, which is one reason many trucks carry warnings not to follow too close, such as "if you can't see my mirrors, I can't see you." This is partly because the driver's position is higher in a tractor-trailer. Larger vehicles also have much larger front and side blind spots. Tractor-trailers have not only large rear quarter blind spots, but also a large blind spot directly to their left and to their front-right.
Every tractor-trailer operator is aware of the simple problem of blind spots. They want their vehicles to function safely in every area of operation. Truck owners know that the roadways are getting more and more congested everyday and the costs associated even with a minor accident, continue to sky-rocket. Insurance costs go up and there is ultimately an effect on the bottom-line of the income statement of the operation.
Sound accident and safety prevention programs can greatly aid the operator. It is also extremely important to remember that, in addition to thorough training, part of the programs need to include giving the operator the tools necessary to put that training into practice.
An analysis of the typical tractor-trailer combination can provide an outline to discuss problems with all equipment.
Government regulations and mandates as to exterior mirrors
Many operators have expressed concerns regarding the Federal Motor Vehicle Safety Standards (FMVSS) developed by the National Highway Traffic Safety Administration (NHTSA) that sets regulation for the mirrors on vehicles that travel the roadways.
The reality of this regulation is that, it only applies to the manufacturer of the vehicle at the time the vehicle is delivered to the buyer. Once the owner takes delivery of the vehicle, they are not bound by the standard. Further, the regulation is deemed by NHTSA to only state “minimum requirements”. Finally, the manufacturer is only required by FMVSS 111 standards, to provide a 7 x 7 inch flat glass mirror (Unit of Magnification) on both sides of the vehicle. There are no requirements in the Standard for supplementary mirrors on these types of vehicles. It is important to note however; that owners and operators are allowed to exceed these requirements if they want to.
The operator of the tractor-trailer combination must clearly understand that the flat glass (Unit of Magnification) mirror provides a field of view for the operator totally determined by the size of the mirror. This type of mirror will only provide some 5 to 10 degrees coverage of the 360 degrees of view necessary. We recognize that this will help the operator in backing the unit, because it will give the driver an accurate perception of the area behind the vehicle.
These mirrors will be of no aid to operator when making lane changes and turning maneuvers on the road. A supplementary mirror, that will provide additional view, becomes a necessity.
Role of the truck manufacturer in the mirroring process
The truck manufacturer has attempted to fill the need of the purchaser and operator by expanding the mirror coverage on their units. The typically offer only a few choices at the time the truck is being purchased.
Historically, truck manufacturers have not spent a great deal of time understanding the function of the mirrors they are placing on their trucks. Most of them offer many types and options but they really do not have any idea what these options will accomplish and generally purchase what "looks good".
The operator is then left with the final determination and this poses the following questions:
Do they buy the mirror because it looks good on the vehicle.
Do they buy the mirror because we have always bought this way?
Do they buy the mirror because that is all that is offered?
More importantly, do they buy the mirror with some knowledge of what they want the mirrors to accomplish?
Inherent problems with configuration of the tractor-trailer combination that contribute to mirroring problems
The manufacturer has placed the exterior mirrors on the door frame on each side of these vehicles, which places the mirrors some 10 to 15 feet from the front end of the truck. Unless the operator can physically see into these areas, it is impossible to detect any obstacle in the blind spot in front of these mirrors.
Currently, the practice is to build larger and larger trucks and, without proper mirrors, the operator must stand up in the seat to look into these blind areas. This feat is not easily accomplished under any conditions and is especially dangerous in heavy traffic conditions.
Because of the many blind spots on commercial vehicles, motorists find themselves in these blind spots and in turn experience accidents when big trucks change lanes. The National Highway Traffic Safety Administration was asked to make a requirement that big trucks have supplementary mirrors placed on the front fenders to prevent this type of accident. The petition was denied by te Administration on grounds that further research was necessary.
Thankfully, a large part of the trucking industry has recognized the common sense of the need for this type of mirror configuration. They are voluntarily equipping their fleets with fender mounted mirrors on both sides of the vehicles. Once the decision has been reached as to the proper location on the front fender, the selection of the proper spot mirror to do the job is required. Currently, the industry-standard mirror for fender or hood mounting is the round 8 inch convex mirror.
When we developed our spot mirror technology we considered the most often used spot mirror the 8 inch round convex that has become the mirror of choice for front fender mounts.
We examined where this type of technology could be improved and concluded that there were 3 major areas where performance could be improved.
Field of view in the Truck
The field of view provided by the round convex supplemental mirror is cone shaped. This basically gives the operator a triangular view, starting at the mirror location and, traveling back to the spot where the ground first becomes visible.Spot mirrors, that are located on the front fenders, are usually about 6 feet from the ground level.We found that the location where the operator first sees the ground is 40 to 50 feet from the mirror location.This means that persons or objects along the immediate side of the unit, are in the blind spot and are unseen by the operator. Even a small vehicle could be in this area and would be invisible to the operator during a turn or lane change.
Glare
When hood or fender mounted mirrors are located in front of the driver, glare from bright lights or the sun could directly reflect into the operator's eyes.This in turn can create a blind spot and some confusion regarding what is actually seen in the mirror.
Our M-C technology solution was to use anti-glare glass in our mirrors. This provided a glass that drastically reduces blindness from bright sunny days and glaring headlights at night. Our mirrors will give the operator a maximum view no matter what light conditions are present.
Distortion
Distortion is another critical problem that operators have had to contend with in using the standard convex mirrors. This makes it very difficult to determine what the obstacle is and precludes the driver from correctly assessing where that person or object is in relation to their vehicle. This makes it extremely difficult to safely make maneuvers and lane changes. For over thirty years, the NHSTA has used distortion as one of the major factors to endorse or require standard spot mirrors for trucks under the Federal Motor Vehicle Safety Standards.
NHTSA states the problem in NHSTA Docket No. 2002-12347 as follows:
“The main difference is that, the image of an object in a standard convex mirror, is both distorted and smaller than that of the same object viewed in a flat mirror. Therefore, such an object appears farther away and, could be less recognizable when viewed in a convex mirror.Additionally, if the object were approaching or receding, its rate of speed and change in position are more difficult to judge as well."
The simple fact remains that, anytime glass is bent, as it is with the convex mirror, the images produced will be changed from the original.
Tractor-trailers operate as a part of either domestic or international transport infrastructures to support containerized cargo shipments. With millions of tractor-trailers on the road, blind spot areas are in abundance and threaten the safety of all drivers who share the road. 
Field of view in the Truck
