In the United States, shipments larger than about 7,000 kg (15,432 lb)are classifiedas truckload freight (TL). It is more efficient and affordable for a large shipment to have exclusive use of one larger trailer. Thisis opposedto having to share space on a smaller Less than Truckload freight carrier.
Trailer stability can be defined as the tendency of a trailer to dissipate side-to-side motion. The initial motion may be caused by aerodynamic forces, such as from a cross wind or a passing vehicle. One common criterion for stability is the center of mass location with respect to the wheels, which can usually be detected by tongue weight. If the center of mass of the trailer is behind its wheels, therefore having a negative tongue weight, the trailer will likely be unstable. Another parameter which is less commonly a factor is the trailer moment of inertia. Even if the center of mass is forward of the wheels, a trailer with a long load, and thus large moment of inertia, may be unstable.
In the United States, the Commercial Motor Vehicle Safety Act of 1986 established minimum requirements that must be met when a state issues a commercial driver's license CDL. It specifies the following types of license: - Class A CDL drivers. Drive vehicles weighing 26,001 pounds or greater, or any combination of vehicles weighing 26,001 pounds or greater when towing a trailer weighing more than 10,000 pounds. Transports quantities of hazardous materials that require warning placards under Department of Public Safety regulations. - Class A Driver License permits. Is a step in preparation for Class A drivers to become a Commercial Driver. - Class B CDL driver. Class B is designed to transport 16 or more passengers (including driver) or more than 8 passengers (including the driver) for compensation. This includes, but is not limited to, tow trucks, tractor trailers, and buses.
In order toload or unloadbotsand other cargo to and from a trailer, trailer winchesare designedfor this purpose. They consist of a ratchet mechanism and cable. The handle on the ratchet mechanism is then turned to tighten or loosen the tension on the winch cable. Trailer winches vary, some are manual while othersare motorized. Trailer winches are mosttypicallyfound on the front of the trailer by towing an A-frame.
Some trailers canbe towed byan accessible pickup truck or van, which generally need no special permit beyond a regular license. Such examples wouldbe enclosedtoy trailers and motorcycle trailers. Specialized trailers like an open-air motorcycle trailer and bicycle trailers are accessible.Some trailers are much more accessible to small automobiles, as are some simple trailers pulled by a drawbar and riding on a single set of axles.Other trailers also have a variety, such as a utility trailer, travel trailers or campers, etc. to allow for varying sizes of tow vehicles.
The American Moving & Storage Association (AMSA) is a non-profit trade association.AMSA represents members of the professional moving industryprimarilybased in the United States. The association consists of approximately 4,000 members. They consist of van lines, their agents, independent movers, forwarders, and industry suppliers.However, AMSA does not represent the self-storage industry.