Commercial vehicles are obviously much larger than a typical passenger car or pickup truck, and they operate much differently. While a passenger car generally weighs 5000 pounds or less, a big rig can weigh up to 80,000 pounds.
The gross axle weight rating on a tractor-trailer is the maximum weight that an axle is designed to carry. Such things as the suspension type, the number of wheels pro axle, and suggested tire ratings can all affect the gross axle weight rating. The gross axle weight is the weight of the load that a particular axle is supporting. An axle rating should never be exceeded for the axle Period.
The gross vehicle weight rating or (GVWR), is the maximum cargo weight plus the vehicle weight which a big rig is designed to accommodate. The gross combined weight rating is the maximum combined safe weight that the tractor-trailer can accommodate. Many people mistakenly believe that adding the gross vehicle weight rating of the tractor and also the trailer gives the combined total for the vehicle. That is not the case, however.
In today’s trucking industry big rigs are assembled by various different manufactures components. The largest truck manufacturers for the United States market include Navistar, Freightliner, Peterbilt, Mack, Kenworth, and Volvo. Trainers can come from a variety of different manufacturers, and motor carriers are striving to achieve a balance between truck weight and efficiency of care enough for cargo.
Transporting the materials by big trucks is essential to the American economy and is a big part of our economic system. The importance of getting products and materials from one point to another, both timely and economically, can’t be overstated.
As you probably know, most big rigs are run on diesel fuel, however many large companies particularly those whose truck business revolves around a fixed local area are converting their big rigs to natural gas in order to achieve more economical results.
One of the most important areas of concern involving the safety of a tractor-trailer is the braking system. While great advances have been made with the brakes on 18-wheelers, it is still a fact that a big truck takes much longer to stop than a passenger car or pickup truck. Commercial vehicles are typically outfitted with air brakes to stop the heavy vehicles. It is the combination of tractor breaks and trailer brakes working together that safely stop a big rig.
As part of an ongoing safety requirement, commercial drivers must inspect their vehicles prior to beginning any trip. This is called a pre-trip inspection and is akin to the checklist a pilot may go over before getting airborne. Checking of the air brakes is one of the items that must be checked before the big truck is put on the highway. Unfortunately, many professional drivers tend to gloss over the pre-trip inspection in an effort to get on the highway as quickly as possible.
Because a semi-truck is so much heavier than the other traffic around it, the potential for devastating injuries in an accident is always present. It does not take much in the way of speed to result in incapacitating injuries from a big rig accident.