A semi-trailer truck, also known as a semitruck, is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called a fifth wheel.
An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle is supported. In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type of axle is referred to as a spindle.
Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.
Four-wheel drive, also called 4×4 or 4WD, refers to a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case providing an additional output drive shaft and, in many instances, additional gear ranges.
quattro is the trademark used by the automotive brand Audi to indicate that all-wheel drive (AWD) technologies or systems are used on specific models of its automobiles.
A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.
Weigh-in-motion or weighing-in-motion (WIM) devices are designed to capture and record the axle weights and gross vehicle weights as vehicles drive over a measurement site. Unlike static scales, WIM systems are capable of measuring vehicles traveling at a reduced or normal traffic speed and do not require the vehicle to come to a stop. This makes the weighing process more efficient, and, in the case of commercial vehicles, allows for trucks under the weight limit to bypass static scales or inspection.
Road signs in the United Kingdom and in its associated Crown dependencies and overseas territories conform broadly to European design norms, though a number of signs are unique: direction signs omit European route numbers and road signs generally use the Imperial System of units, unlike the rest of Europe. Signs in Wales and parts of Scotland are bilingual.
Road signs in Sweden are regulated in Vägmärkesförordningen, VMF (2007:90), and are to be placed 2 metres from the road with the sign 1.6 m from the base for motorized roads. Except for route numbers, there are a maximum of three signs on a pole, with the most important sign at the top. All signs have a reflective layer added on selected parts of the sign as is custom in European countries; most larger signs also have their own illumination.
Route Availability (RA) is the system by which the permanent way and supporting works of the railway network of Great Britain are graded. All routes are allocated an RA number between 1 and 10.
A tractor unit is a characteristically heavy-duty towing engine that provides motive power for hauling a towed or trailered load. These fall into two categories: heavy- and medium-duty military and commercial rear-wheel-drive semi-tractors used for hauling semi-trailers, and very heavy-duty typically off-road-capable, often 6×6, military and commercial tractor units, including ballast tractors.
A truck scale (US), weighbridge (non-US) or railroad scale is a large set of scales, usually mounted permanently on a concrete foundation, that is used to weigh entire rail or road vehicles and their contents. By weighing the vehicle both empty and when loaded, the load carried by the vehicle can be calculated.
Truck classifications are typically based upon the maximum loaded weight of the truck, typically using the gross vehicle weight rating (GVWR) and sometimes also the gross trailer weight rating (GTWR), and can vary among jurisdictions.
The Federal Bridge Gross Weight Formula, also known as Bridge Formula B or the Federal Bridge Formula, is a mathematical formula in use in the United States by truck drivers and Department of Transportation (DOT) officials to determine the appropriate maximum gross weight for a commercial motor vehicle (CMV) based on axle number and spacing. The formula is part of federal weight and size regulations regarding interstate commercial traffic. The formula is necessary to prevent heavy vehicles from damaging roads and bridges. CMVs are most often tractor-trailers or buses, but the formula is of most interest to truck drivers due to the heavy loads their vehicles often carry.
The Military Load Classification (MLC) is a system of standards used by NATO to classify the safe amount of load a surface can withstand. Load-carrying capacity is shown in whole numbers for vehicles, bridges, roads, and routes. Vehicles are classified by weight, type, and effect on routes. Bridges, roads, and routes are classified by physical characteristics, type and flow of traffic, effects of weather, and other special conditions.
The use of markings on British military vehicles expanded and became more sophisticated following the mass production and mechanization of armies in World War II.
Military markings on United States army vehicles were upgraded in August 1942 when specific new rules were adopted. New marks, from the national identification symbol downwards were ordered to be put on "all motor vehicles assigned to tactical units".
Road signs in the Philippines are regulated and standardized by the Department of Public Works and Highways (DPWH). Most of the signs reflect minor influences from US and Australian signs, but keep a design closer to the Vienna Convention on Road Signs and Signals in which the Philippines is an original signatory.
A platform chassis is a form of vehicle frame / automobile chassis, constructed as a flat plate or platform, sometimes integrating a backbone or frame-structure with a vehicle's floor-pan.
Vehicle weight is a measurement of wheeled motor vehicles; either an actual measured weight of the vehicle under defined conditions or a gross weight rating for its weight carrying capacity.
