1.
Thermal expansion
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Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature. Temperature is a function of the average molecular kinetic energy of a substance. When a substance is heated, the energy of its molecules increases. Thus, the molecules begin vibrating/moving more and usually maintain an average separation. Materials which contract with increasing temperature are unusual, this effect is limited in size, the degree of expansion divided by the change in temperature is called the materials coefficient of thermal expansion and generally varies with temperature. If an equation of state is available, it can be used to predict the values of the expansion at all the required temperatures and pressures. A number of contract on heating within certain temperature ranges. For example, the coefficient of expansion of water drops to zero as it is cooled to 3. Also, fairly pure silicon has a coefficient of thermal expansion for temperatures between about 18 and 120 Kelvin. Unlike gases or liquids, solid materials tend to keep their shape when undergoing thermal expansion, in general, liquids expand slightly more than solids. The thermal expansion of glasses is higher compared to that of crystals, at the glass transition temperature, rearrangements that occur in an amorphous material lead to characteristic discontinuities of coefficient of thermal expansion and specific heat. These discontinuities allow detection of the transition temperature where a supercooled liquid transforms to a glass. Absorption or desorption of water can change the size of common materials. Common plastics exposed to water can, in the long term, the coefficient of thermal expansion describes how the size of an object changes with a change in temperature. Specifically, it measures the change in size per degree change in temperature at a constant pressure. Several types of coefficients have been developed, volumetric, area, which is used depends on the particular application and which dimensions are considered important. For solids, one might only be concerned with the change along a length, the volumetric thermal expansion coefficient is the most basic thermal expansion coefficient, and the most relevant for fluids. In general, substances expand or contract when their temperature changes, substances that expand at the same rate in every direction are called isotropic
2.
Building
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A building or edifice is a structure with a roof and walls standing more or less permanently in one place, such as a house or factory. To better understand the term building compare the list of nonbuilding structures, Buildings serve several needs of society – primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a division of the human habitat. Ever since the first cave paintings, buildings have become objects or canvasses of much artistic expression. In recent years, interest in planning and building practices has also become an intentional part of the design process of many new buildings. The word building is both a noun and a verb also an adverb, the structure itself and the act of making it. As a noun, a building is a structure that has a roof and walls and stands more or less permanently in one place, there was a building on the corner. In the broadest interpretation a fence or wall is a building, however, the word structure is used more broadly than building including natural and man-made formations and does not necessarily have walls. Structure is more likely to be used for a fence, as a verb, building is the act of construction. Structural height in technical usage is the height to the highest architectural detail on building from street-level, depending on how they are classified, spires and masts may or may not be included in this height. Spires and masts used as antennas are not generally included, the definition of a low-rise vs. a high-rise building is a matter of debate, but generally three storeys or less is considered low-rise. A report by Shinichi Fujimura of a shelter built 500000 years ago is doubtful since Fujimura was later found to have faked many of his findings. Supposed remains of huts found at the Terra Amata site in Nice purportedly dating from 200000 to 400000 years ago have also called into question. There is clear evidence of homebuilding from around 18000 BC, Buildings became common during the Neolithic. Single-family residential buildings are most often called houses or homes, residential buildings containing more than one dwelling unit are called a duplex, apartment building to differentiate them from individual houses. A condominium is an apartment that the occupant owns rather than rents, houses which were built as a single dwelling may later be divided into apartments or bedsitters, they may also be converted to another use e. g. an office or a shop. Building types may range from huts to multimillion-dollar high-rise apartment blocks able to house thousands of people, increasing settlement density in buildings is usually a response to high ground prices resulting from many people wanting to live close to work or similar attractors. Other common building materials are brick, concrete or combinations of either of these with stone, also if the residents are in need of special care such as a nursing home, orphanage or prison, or in group housing like barracks or dormitories
3.
Bridge
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A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose, the Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg, of the same meaning. The word can be traced back to Proto-Indo-European *bʰrēw-. The word for the game of the same name has a different origin. The first bridges made by humans were probably spans of cut wooden logs or planks and eventually stones, using a simple support, some early Americans used trees or bamboo poles to cross small caverns or wells to get from one place to another. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence, several intact arched stone bridges from the Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were the ancient Romans, the Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs. An example is the Alcántara Bridge, built over the river Tagus, the Romans also used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, brick and mortar bridges were built after the Roman era, as the technology for cement was lost. In India, the Arthashastra treatise by Kautilya mentions the construction of dams, a Mauryan bridge near Girnar was surveyed by James Princep. The bridge was swept away during a flood, and later repaired by Puspagupta, the use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India and this bridge is also historically significant as it is the worlds oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge, rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century. During the 18th century there were innovations in the design of timber bridges by Hans Ulrich Grubenmann, Johannes Grubenmann. The first book on bridge engineering was written by Hubert Gautier in 1716, a major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross the river Severn, with the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a tensile strength, much larger bridges were built. In 1927 welding pioneer Stefan Bryła designed the first welded bridge in the world
4.
Sidewalk
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A sidewalk or pavement, also known as a footpath or footway, is a path along the side of a road. A sidewalk may accommodate moderate changes in grade and is separated from the vehicular section by a curb. There may also be a strip or road verge either between the sidewalk and the roadway or between the sidewalk and the boundary. In some places, the term may also be used for a paved path, trail or footpath that is not next to a road, for example. The term sidewalk is usually preferred in most of North America, the term pavement is more common in the United Kingdom, as well as parts of the Mid-Atlantic United States such as Philadelphia and New Jersey. Many Commonwealth countries use the term footpath, the professional, civil engineering and legal term for this in North America is sidewalk while in the United Kingdom it is footway. In the United States, the sidewalk is used for the pedestrian path beside a road. Shared use paths or multi-use paths are available for use by pedestrians and bicyclists. Walkway is a comprehensive term that includes stairs, ramps, passageways. In the UK, the footpath is mostly used for paths that do not abut a roadway. The term shared-use path is used where cyclists are able to use the same section of path as pedestrians. There is evidence that sidewalks were built in ancient times and it was claimed that the Greek city of Corinth was paved by the 4th-century, and the Romans were particularly prolific sidewalk builders – they called them semitas. However, by the Middle Ages, narrow roads had reverted to being used by pedestrians and wagons without any formal separation between the two categories. Early attempts at ensuring the maintenance of foot-ways or sidewalks were often made, such as the 1623 Act for Colchester. Following the Great Fire of London in 1666, attempts were made to bring some order to the sprawling city. Purbeck stone was used as a durable paving material. Bollards were also installed to protect pedestrians from the traffic in the middle of the road, the Corporation was also made responsible for the regular upkeep of the roads, including their cleaning and repair, for which they charged a tax from 1766. By the late 19th-century large and spacious sidewalks were constructed in European capitals
5.
Track (rail transport)
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The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, railroad ties and ballast, plus the underlying subgrade. It enables trains to move by providing a surface for their wheels to roll upon. For clarity it is referred to as railway track or railroad track. Tracks where electric trains or electric trams run are equipped with a system such as an overhead electrical power line or an additional electrified rail. The term permanent way also refers to the track in addition to structures such as fences etc. Most railroads with heavy traffic use continuously welded rails supported by sleepers attached via baseplates that spread the load, a plastic or rubber pad is usually placed between the rail and the tieplate where concrete sleepers are used. The rail is held down to the sleeper with resilient fastenings. For much of the 20th century, rail track used softwood timber sleepers and jointed rails, jointed rails were used at first because contemporary technology did not offer any alternative. The joints also needed to be lubricated, and wear at the mating surfaces needed to be rectified by shimming. For this reason jointed track is not financially appropriate for heavily operated railroads, timber sleepers are of many available timbers, and are often treated with creosote, copper-chrome-arsenic, or other wood preservative. Pre-stressed concrete sleepers are used where timber is scarce and where tonnage or speeds are high. Steel is used in some applications, the track ballast is customarily crushed stone, and the purpose of this is to support the sleepers and allow some adjustment of their position, while allowing free drainage. A disadvantage of traditional track structures is the demand for maintenance, particularly surfacing and lining to restore the desired track geometry. Weakness of the subgrade and drainage deficiencies also lead to maintenance costs. This can be overcome by using ballastless track, in its simplest form this consists of a continuous slab of concrete with the rails supported directly on its upper surface. There are a number of systems, and variations include a continuous reinforced concrete slab. Many permutations of design have been put forward, however, ballastless track has a high initial cost, and in the case of existing railroads the upgrade to such requires closure of the route for a long period. Its whole-life cost can be lower because of the reduction in maintenance, some rubber-tyred metros use ballastless tracks
6.
Cornish Main Line
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The Cornish Main Line is a railway line in Cornwall in the United Kingdom. It runs from Penzance to Plymouth, crossing from Cornwall into Devon over the famous Royal Albert Bridge at Saltash. It directly serves Truro, St Austell, Bodmin, and Liskeard, there are branches off the main line serving St Ives, Falmouth, Newquay, and Looe. It is the southernmost railway line in the United Kingdom, the West Cornwall Railway was itself based on the Hayle Railway, opened in 1837 as a purely local mineral railway. Through goods trains started running in 1866 and passenger trains in 1867, the Associated Companies merged into the Great Western Railway, and in 1892 the Great Western converted all its broad gauge track to standard gauge, a process called the gauge conversion. Those on the Cornwall Railway section are described at Cornwall Railway viaducts, the most iconic structure on the route, however, is the Royal Albert Bridge spanning the River Tamar and opened in 1859, it remains in use to the present day. The physical limitations of the steeply graded line imposed severe problems during the busiest times, equally famous was the line’s use for transporting vegetable produce from Cornwall, famously broccoli and cauliflower, and cut flowers from the Isles of Scilly. To cope with the traffic the line was gradually doubled between 1893 and 1930. The historical development of the line is more fully dealt with at Hayle Railway, West Cornwall Railway, the Cornwall Main Line has been a very safe railway for passengers, although a number of railwaymen have been killed and there have been some memorable accidents over the years. These include, Grove Viaduct, St Germans – derailment,6 May 1859, St Austell – runaway train,29 October 1872. Menheniot – collision,2 December 1873, Bodmin Road – derailment,13 April 1895. The communities served are, Plymouth, Saltash, St Germans, Menheniot, Liskeard, Bodmin, Lostwithiel, Par, St Austell, Truro, Redruth, Camborne, Hayle, St Erth, Penzance. In addition branch lines link Plymouth with Bere Alston, Calstock, and Gunnislake, Liskeard with Looe, Par with Newquay, Truro with Penryn and Falmouth, the railway stations at St Austell and Penzance are adjacent to bus stations. In addition, integrated bus services operate from Bodmin Parkway to Bodmin, Wadebridge, and Padstow, from St Austell to The Eden Project, and from Redruth to Helston and RNAS Culdrose. The route has a number of viaducts, but the most significant structure is the Royal Albert Bridge which crosses the River Tamar at Saltash. Nominal line speed is 65 mph but there are local restrictions at many places, the route is mostly double-tracked and cleared for trains up to W7 and W6A gauges. The second track was restored in August 2004, the total cost of the project was £14.3 million and was funded by Objective One, Strategic Rail Authority and Cornwall County Council. The number of travelling on the Cornish Main Line has increased in the last few years
7.
Railroad switch
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A railroad switch, turnout or points is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off. The switch consists of the pair of linked tapering rails, known as points and these points can be moved laterally into one of two positions to direct a train coming from the point blades toward the straight path or the diverging path. A train moving from the end toward the point blades is said to be executing a facing-point movement. Passage through a switch in this direction is known as a trailing-point movement, a switch generally has a straight through track and a diverging route. The handedness of the installation is described by the side that the track leaves. Right-hand switches have a path to the right of the straight track, when coming from the point blades. In many cases, such as yards, many switches can be found in a short section of track. Sometimes a switch merely divides one track into two, at others, it serves as a connection between two or more tracks, allowing a train to switch between them. A straight track is not always present, for example, both tracks may curve, one to the left and one to the right, or both tracks may curve, with differing radii, while still in the same direction. A railroad cars wheels are guided along the tracks by coning of the wheels, only in extreme cases does it rely on the flanges located on the insides of the wheels. When the wheels reach the switch, the wheels are guided along the route determined by which of the two points is connected to the track facing the switch. In the illustration, if the point is connected, the left wheel will be guided along the rail of that point. If the right point is connected, the right wheels flange will be guided along the rail of that point, and the train will continue along the straight track. Only one of the points may be connected to the track at any time. A mechanism is provided to move the points from one position to the other, historically, this would require a lever to be moved by a human operator, and some switches are still controlled this way. However, most are now operated by a remotely controlled electric motor or by pneumatic or hydraulic actuation and this both allows for remote control and for stiffer, strong switches that would be too difficult to move by hand, yet allow for higher speeds. In a trailing-point movement, the flanges on the wheels will force the points to the proper position and this is sometimes known as running through the switch. Some switches are designed to be forced to the position without damage
8.
Metal expansion joint
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Metal expansion joints are compensating elements for thermal expansion and relative movement in pipelines, containers and machines. They consist of one or more metal bellows, connectors at both ends, and tie rods that depend on the application and they are differentiated according to the three basic types of movement, axial, angular and lateral expansion joints. Emil Witzenmann was considered the inventor of expansion joints, in 1920, he applied for a patent for the first so-called flexible metal tube expansion joint, German Reichspatent No.367185, from 29 July 1920. From a technical point of view, this precursor of todays expansion joints is a large, in the 1930s, the metal hose or flexible metal tube principle was replaced by the metal bellows as the central functional element. This design principle – metal bellows with connection pieces – is still the basis of modern metal expansion joints today. However, records now show that a factory was Founding of Henri Ehrmann & Co. a factory for metal cartridges in Karlsruhe / Germany in 1872, in modern expansion joints, the metal bellows are often produced with a so-called multi-ply design. To increase both flexibility and stability, multiple thin plies of metal are layered to form the bellows walls, there are two basic design types, The multi-ply and the multi-walled bellows structure. The multi-ply structure consists of a pressure-tight, longitudinally welded outer and inner cylinder of stainless steel, in between these cylinders is an open, spiral cylinder which forms multiple plies depending on the design. The multi-walled structure consists of concentric, longitudinally welded cylinders. Each cylinder forms a pressure-tight and closed wall, in axial compensation, the thermal expansion of a straight line section between two fixed points is absorbed by an axial expansion joint. The distance between two fixed points defines the pipeline length requiring compensation, and thus determines the movement that must be achieved by the expansion joint. The fixed points must be designed to withstand the pressure and spring forces of the expansion joint, the frictional forces of the pipe guides. Long pipes must be protected against kinking between the points using pipe guides. The axial expansion joint should be installed in the vicinity of a fixed point. Impermissibly large fixed point loads can be prevented by using axial expansion joints that are relieved of pressure forces, the angular compensation of thermal expansion requires at least two, and for full compensation even three, angular expansion joints. Angular expansion joints offer a variety of combination options in so-called two-hinge or three-hinge systems. The following basic rules apply to angular compensation, Always at least two angular expansion joints are needed, angular expansion joints are always associated with multiple redirections of flow by 90°. Angular compensation is specifically designed for complex multi-plane pipework, lateral compensation is likewise associated with a redirection of flow by 90° within single-plane or multi-plane piping systems
9.
Flange
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Thus flanged wheels are wheels with a flange on one side to keep the wheels from running off the rails. The term flange is used for a kind of tool used to form flanges. Pipes with flanges can be assembled and disassembled easily, a flange can also be a plate or ring to form a rim at the end of a pipe when fastened to the pipe. A blind flange is a plate for covering or closing the end of a pipe, a flange joint is a connection of pipes, where the connecting pieces have flanges by which the parts are bolted together. Surrey and York flanges fit to the top of the hot water tank allowing all the water to be taken without disturbance to the tank and they are often used to ensure an even flow of water to showers. An Essex flange requires a hole to be drilled in the side of the tank, there is also a Warix flange which is the same as a York flange but the shower output is on the top of the flange and the vent on the side. The York and Warix flange have female adapters so that they fit onto a male tank, a closet flange provides the mount for a toilet. There are many different flange standards to be found worldwide, to allow easy functionality and inter-changeability, these are designed to have standardised dimensions. Common world standards include ASA/ANSI/ASME, PN/DIN, BS10, and JIS/KS, in most cases these are interchangeable as most local standards have been aligned to ISO standards, however some local standards still differ. Further, many of the flanges in each standard are divided into pressure classes, again these are not generally interchangeable. These pressure classes also have differing pressure and temperature ratings for different materials, the ANSI/ASME pressure classes for Flat-Face flanges are 125# and 250#. The classes for Ring-Joint, Tongue & Groove, and Raised-Face flanges are 150#, 300#, 600#, 900#, 1500#, and 2500#. The flange faces are made to standardized dimensions and are typically flat face, raised face, tongue and groove, or ring joint styles. Flange designs are available as weld neck, slip-on, lap joint, socket weld, threaded, Pipe flanges that are made to standards called out by ASME B16.5 or ASME B16.47 are typically made from forged materials and have machined surfaces. B16.5 refers to nominal pipe sizes from ½ to 24, B16.47 covers NPSs from 26 to 60. However these classes do not correspond to maximum pressures in psi, instead, the maximum pressure depends on the material of the flange and the temperature. For example, the pressure for a Class 150 flange is 285 psi. The gasket type and bolt type are generally specified by the standard, however, sometimes the standards refer to the ASME Boiler and these flanges are recognized by ASME Pipe Codes such as ASME B31.1 Power Piping, and ASME B31.3 Process Piping
10.
Steam
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Steam is water in the gas phase, which is formed when water boils. Steam is invisible, however, steam often refers to wet steam, at lower pressures, such as in the upper atmosphere or at the top of high mountains, water boils at a lower temperature than the nominal 100 °C at standard pressure. If heated further it becomes superheated steam, piston type steam engines played a central role to the Industrial Revolution and modern steam turbines are used to generate more than 80% of the worlds electricity. If liquid water comes in contact with a hot surface or depressurizes quickly below its vapor pressure. Steam explosions have been responsible for many accidents, and may also have been responsible for much of the damage to the plant in the Chernobyl disaster. Steam is traditionally created by heating a boiler via burning coal and other fuels, water vapor that includes water droplets is described as wet steam. As wet steam is heated further, the droplets evaporate, and at a high temperature all of the water evaporates. Superheated steam is steam at a higher than its boiling point for the pressure. Steam tables contain thermodynamic data for water/steam and are used by engineers and scientists in design. Additionally, thermodynamic phase diagrams for water/steam, such as a diagram or a Mollier diagram shown in this article. Steam charts are used for analysing thermodynamic cycles. In agriculture, steam is used for sterilization to avoid the use of harmful chemical agents. Steams capacity to transfer heat is used in the home, for cooking vegetables, steam cleaning of fabric, carpets and flooring. In each case, water is heated in a boiler, steam is also used in ironing clothes to add enough humidity with the heat to take wrinkles out and put intentional creases into the clothing. About 90% of all electricity is generated using steam as the working fluid, in electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. However, in cogeneration, steam is piped into buildings through a heating system to provide heat energy after its use in the electric generation cycle. The worlds biggest steam generation system is the New York City steam system, in other industrial applications steam is used for energy storage, which is introduced and extracted by heat transfer, usually through pipes. Steam is a reservoir for thermal energy because of waters high heat of vaporization
11.
Bellows
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A bellows or pair of bellows is a device constructed to furnish a strong blast of air. It has many applications, in particular blowing on a fire to supply it with air, the term bellows is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight bag allowing the distance between the lens and film of a photographic camera to be varied is called a bellows. Bellows is only used in plural, the Old English name for bellows was blǽstbęlg, blást-bęlg blast-bag, blowing-bag, the prefix was dropped and by the eleventh century the simple bęlg, bylg, bylig was used. The word is cognate with belly, there are similar words in Old Norse, Swedish, and Danish, but the derivation is not certain. Bellows appears not to be cognate with the apparently similar Latin follis, several processes, such as metallurgical iron smelting and welding, require so much heat that they could only be developed after the invention, in antiquity, of the bellows. The bellows are used to deliver air to the fuel, raising the rate of combustion. Various kinds of bellows are used in metallurgy, Box bellows were and are used in Asia. Pot bellows were used in ancient Egypt, accordion bellows, with the characteristic pleated sides, have been used in Europe for many centuries. Piston bellows were developed in the middle of the 18th century in Europe, however, the double action piston bellows were utilised by the Han rulers in ancient China as early as the 3rd century BC. Metal bellows were made to absorb axial movement in a dynamic condition, often referred to as Axial Dynamics bellows types. The Han Dynasty Chinese mechanical engineer Du Shi is credited with being the first to apply power, through a waterwheel. His invention was used to operate piston bellows of blast furnaces in order to forge cast iron, the ancient Greeks, ancient Romans, and other civilizations used bellows in bloomery furnaces producing wrought iron. Bellows are also used to send pressurized air in a manner in a fired heater. In modern industry, reciprocating bellows are usually replaced with motorized blowers and these bellows blow a more constant, and thus stronger, blast than simple bellows. Such bellows existed in China at least since the 5th century BC, when it was invented, a piston is enclosed in a rectangular box with a handle coming out one side. The piston edges are covered with feathers, fur, or soft paper to ensure that it is airtight and lubricated. As the piston is pulled, air from one side enters and flows through the nozzle and as it is pushed air enters from the opposite side, the middle leave is fixed in place
12.
Stainless steel
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In metallurgy, stainless steel, also known as inox steel or inox from French inoxydable, is a steel alloy with a minimum of 10. 5% chromium content by mass. Stainless steel is notable for its resistance, and it is widely used for food handling. Stainless steel does not readily corrode, rust or stain with water as ordinary steel does, however, it is not fully stain-proof in low-oxygen, high-salinity, or poor air-circulation environments. There are various grades and surface finishes of stainless steel to suit the environment the alloy must endure, Stainless steel is used where both the properties of steel and corrosion resistance are required. Stainless steel differs from carbon steel by the amount of chromium present, unprotected carbon steel rusts readily when exposed to air and moisture. This iron oxide film is active and accelerates corrosion by making it easier for more iron oxide to form, since iron oxide has lower density than steel, the film expands and tends to flake and fall away. In comparison, stainless steels contain sufficient chromium to undergo passivation and this layer prevents further corrosion by blocking oxygen diffusion to the steel surface and stops corrosion from spreading into the bulk of the metal. Passivation occurs only if the proportion of chromium is high enough, Stainless steel’s resistance to corrosion and staining, low maintenance, and familiar lustre make it an ideal material for many applications. Storage tanks and tankers used to transport orange juice and other food are made of stainless steel. This also influences its use in kitchens and food processing plants, as it can be steam-cleaned and sterilized. High oxidation resistance in air at ambient temperature is achieved with addition of a minimum of 13% chromium. The chromium forms a layer of chromium oxide when exposed to oxygen. The layer is too thin to be visible, and the metal remains lustrous, the layer is impervious to water and air, protecting the metal beneath, and this layer quickly reforms when the surface is scratched. This phenomenon is called passivation and is seen in other metals, corrosion resistance can be adversely affected if the component is used in a non-oxygenated environment, a typical example being underwater keel bolts buried in timber. When stainless steel parts such as nuts and bolts are forced together, when forcibly disassembled, the welded material may be torn and pitted, a destructive effect known as galling. Galling can be avoided by the use of materials for the parts forced together, for example bronze and stainless steel. However, two different alloys electrically connected in a humid, even mildly acidic environment may act as a voltaic pile, nitronic alloys, made by selective alloying with manganese and nitrogen, may have a reduced tendency to gall. Additionally, threaded joints may be lubricated to provide a film between the two parts and prevent galling, low-temperature carburizing is another option that virtually eliminates galling and allows the use of similar materials without the risk of corrosion and the need for lubrication
13.
Polytetrafluoroethylene
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Polytetrafluoroethylene is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. The best known name of PTFE-based formulas is Teflon by Chemours. Chemours is a spin-off of DuPont Co. which discovered the compound in 1938, PTFE is a fluorocarbon solid, as it is a high-molecular-weight compound consisting wholly of carbon and fluorine. PTFE is hydrophobic, neither water nor water-containing substances wet PTFE, PTFE has one of the lowest coefficients of friction of any solid. PTFE is used as a coating for pans and other cookware. It is very non-reactive, partly because of the strength of carbon–fluorine bonds, where used as a lubricant, PTFE reduces friction, wear and energy consumption of machinery. It is commonly used as a material in surgical interventions. Also, it is employed as coating on catheters, this interferes with the ability of bacteria and other infectious agents to adhere to catheters. PTFE was accidentally discovered in 1938 by Roy Plunkett while he was working in New Jersey for DuPont. Since Plunkett was measuring the amount of gas used by weighing the bottle, he became curious as to the source of the weight and he found the bottles interior coated with a waxy white material that was oddly slippery. Analysis showed that it was polymerized perfluoroethylene, with the iron from the inside of the container having acted as a catalyst at high pressure, Kinetic Chemicals patented the new fluorinated plastic in 1941, and registered the Teflon trademark in 1945. By 1948, DuPont, which founded Kinetic Chemicals in partnership with General Motors, was producing two million pounds of Teflon brand PTFE per year in Parkersburg, West Virginia. In 1954, the wife of French engineer Marc Grégoire urged him to try the material he had been using on fishing tackle on her cooking pans and he subsequently created the first Teflon-coated, non-stick pans under the brandname Tefal. In the United States, Marion A. Trozzolo, who had been using the substance on scientific utensils, marketed the first US-made Teflon-coated pan, The Happy Pan, however, Tefal was not the only company to utilize PTFE in nonstick cookware coatings. Other cookware companies, such as Meyer Corporations Anolon, use Teflon nonstick coatings purchased from DuPont, in the 1990s, it was found that PTFE could be radiation cross-linked above its melting point in an oxygen-free environment. Electron beam processing is one example of radiation processing, cross-linked PTFE has improved high-temperature mechanical properties and radiation stability. This was significant because, for years, irradiation at ambient conditions has been used to break down PTFE for recycling. This radiation-induced chain scission allows it to be more easily reground, PTFE is produced by free-radical polymerization of tetrafluoroethylene
14.
Elastomer
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An elastomer is a polymer with viscoelasticity and very weak inter-molecular forces, generally having low Youngs modulus and high failure strain compared with other materials. The term, which is derived from elastic polymer, is used interchangeably with the term rubber. Each of the monomers which link to form the polymer is made of carbon. Elastomers are amorphous polymers existing above their glass transition temperature, so that considerable segmental motion is possible, at ambient temperatures, rubbers are thus relatively soft and deformable. Their primary uses are for seals, adhesives and molded flexible parts, application areas for different types of rubber are manifold and cover segments as diverse as tires, shoe soles, and dampening and insulating elements. The importance of rubbers can be judged from the fact that global revenues are forecast to rise to US$56 billion in 2020, Rubber like solids with elastic properties are called elastomers. Polymer chains are held together in elastomers by weakest intermolecular forces and this weak binding forces permit the polymers to be stretched. Natural rubber, neoprene rubber, buna-s and buna-n are elastomers, elastomers are usually thermosets but may also be thermoplastic. The long polymer chains cross-link during curing, i. e. vulcanizing, the molecular structure of elastomers can be imagined as a spaghetti and meatball structure, with the meatballs signifying cross-links. The elasticity is derived from the ability of the chains to reconfigure themselves to distribute an applied stress. The covalent cross-linkages ensure that the elastomer will return to its original configuration when the stress is removed, as a result of this extreme flexibility, elastomers can reversibly extend from 5-700%, depending on the specific material. Without the cross-linkages or with short, uneasily reconfigured chains, the stress would result in a permanent deformation. Temperature effects are present in the demonstrated elasticity of a polymer. It is also possible for a polymer to exhibit elasticity that is not due to covalent cross-links, butyl rubber Halogenated butyl rubbers Styrene-butadiene Rubber Nitrile rubber, also called Buna N rubbers Hydrogenated Nitrile Rubbers Therban and Zetpol. One should go through all differentiation while editing between Plastics and articles thereof and Rubber and articles thereof
15.
Rubber
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Natural rubber, also called India rubber or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds, plus water. Malaysia and Indonesia are two of the leading rubber producers, forms of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the tree or others. The latex is a sticky, milky colloid drawn off by making incisions in the bark, the latex then is refined into rubber ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup, the coagulated lumps are collected and processed into dry forms for marketing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials, in most of its useful forms, it has a large stretch ratio and high resilience, and is extremely waterproof. The major commercial source of rubber latex is the Pará rubber tree. This species is preferred because it grows well under cultivation, a properly managed tree responds to wounding by producing more latex for several years. Congo rubber, formerly a source of rubber, came from vines in the genus Landolphia. These cannot be cultivated, and the drive to collect latex from wild plants was responsible for many of the atrocities committed under the Congo Free State. The latex exhibits the quality as the natural rubber from rubber trees. In the wild types of dandelion, latex content is low, in Nazi Germany, research projects tried to use dandelions as a base for rubber production, but failed. In collaboration with Continental Tires, IME began a pilot facility, many other plants produce forms of latex rich in isoprene polymers, though not all produce usable forms of polymer as easily as the Pará. Some of them require more processing to produce anything like usable rubber. Some produce other desirable materials, for example gutta-percha and chicle from Manilkara species, the term gum rubber is sometimes applied to the tree-obtained version of natural rubber in order to distinguish it from the synthetic version. The first use of rubber was by the cultures of Mesoamerica. The earliest archeological evidence of the use of latex from the Hevea tree comes the Olmec culture. The Pará rubber tree is indigenous to South America, charles Marie de La Condamine is credited with introducing samples of rubber to the Académie Royale des Sciences of France in 1736
16.
Earthquake
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An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earths lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to people around. The seismicity or seismic activity of an area refers to the frequency, type, Earthquakes are measured using measurements from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe and these two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly imperceptible or weak and magnitude 7 and over potentially cause damage over larger areas. The largest earthquakes in historic times have been of magnitude slightly over 9, intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the damage to structures it causes. At the Earths surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground, when the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity, in its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of faults, but also by other events such as volcanic activity, landslides, mine blasts. An earthquakes point of rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter, tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior, once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the portion of the fault. This energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface and this process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of a total energy is radiated as seismic energy. Most of the energy is used to power the earthquake fracture growth or is converted into heat generated by friction
17.
Toroidal expansion joint
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Convolutions are the portion of the bellows that allow it to be flexible. The convolutions are formed around reinforcing bands so that only the portion of the torus allows for flexibility. Toroidal expansion joints are used in high pressure applications, where little movement is required. Usually, they are formed, but others are free formed. These expansion joints are also referred to as Omega bellows due to their shape resembling the Greek letter, expansion Joint Manufacturers Association EJMA http, //www. ejma. org
18.
Copper in architecture
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Copper has earned a respected place in the related fields of architecture, building construction, and interior design. The history of copper in architecture can be linked to its durability, corrosion resistance, prestigious appearance, for centuries, craftsmen and designers utilized these attributes to build aesthetically pleasing and long-lasting building systems. For the past quarter century, copper has been designed into a wider range of buildings, incorporating new styles, varieties of colors. Copper clad walls are a design element in both indoor and outdoor environments. Some of the worlds most distinguished modern architects have relied on copper, architect Frank O. Gehry’s enormous copper fish sculpture atop the Vila Olimpica in Barcelona is an example of the artistic use of copper. Copper’s most famous trait is its display from a metallic colour to iridescent brown to near black. Architects describe the array of browns as russet, chocolate, plum, mahogany, the metal’s distinctive green patina has long been coveted by architects and designers. This article describes practical and aesthetic benefits of copper in architecture as well as its use in applications, interior design elements. Copper has played a role in architecture for thousands of years, for example, in ancient Egypt, massive doors to the temple of Amen-Re at Karnak were clad with copper. In the 3rd Century B. C. copper roof shingles were installed atop of the Lowa Maha Paya Temple in Sri Lanka, and the Romans used copper as roof covering for the Pantheon in 27 B. C. Centuries later, copper and its alloys were integral in medieval architecture, the doors of the Church of the Nativity at Bethlehem are covered with plates of bronze, cut out in patterns. Those of Hagia Sophia at Constantinople, of the 8th and 9th century, are wrought in bronze, bronze doors on the Aachen Cathedral in Germany date back to about 800 A. D. Bronze baptistery doors at the Cathedral of Florence were completed in 1423 A. D. by Ghiberti, the copper roof of Hildesheim Cathedral, installed in 1280 A. D. survives to this day. And the roof at Kronborg, one of northern Europes most important Renaissance castles that was immortalized as Elsinore Castle in Shakespeare’s Hamlet, was installed in 1585 A. D, the copper on the tower was renovated in 2009. For years, copper was reserved mainly for public institutions, such as churches, government buildings, Copper roofs are often one of the most architecturally distinguishable features of these structures. In the 21st century, the use of copper continues to evolve in the indoor environment and its recently proven antimicrobial properties reduce pathogenic bacterial loads on such products as handrails, bedrails, bathroom fixtures, counter tops, etc. These antimicrobial copper-based products are now being incorporated into public facilities as well as in residential buildings because of the health benefits. As an architectural metal, copper provides excellent corrosion resistance, Copper surfaces form tough oxide-sulfate patina coatings that protect underlying copper surfaces and resist corrosion for a very long time
19.
Reinforced rubber
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Although seldom shared under this name, one of the largest groups of composite materials worldwide is that of the reinforced rubber products. Familiar examples are automobile tyres, hoses and conveyor belts, reinforced rubber products combine a rubber matrix and a reinforcing material, so high strength to flexibility ratios can be achieved. The reinforcing material, usually a kind of fibre, provides the strength, the rubber matrix, with low strength and stiffness, provides air-fluid tightness and supports the reinforcing materials to maintain their relative positions. These positions are of importance because they influence the resulting mechanical properties. A composite structure where all fibres are loaded equally everywhere when pressurized, is called an isotropic structure, to meet the isotensoidal concept the structure geometry must have an isotensoid meridian profile and the fibres must be positioned following geodesic paths. A geodesic path connects two points on a continuous surface by means of the shortest possible way. To achieve optimal loading in a rubber hose the fibres must be positioned under an angle of approximately 54.7 angular degrees. The magic angle of 54.7 exactly balances the internal-pressure-induced longitudinal stress, if the fiber angle is initially above or below 54. The equilibrium state is an angle of 54.7. In this situation the fibres tend to be loaded purely in tension, when the fibres of the reinforcement structure are placed under angles larger than 54.7 angular degrees, the fibres want to relocate to their optimal path when pressurized. This means that the fibres will re-orient themselves until they have reached their force equilibrium, in this case this will lead to an increase in length and a decrease in diameter. With angles smaller than 54.7 degrees the opposite will occur, a product which makes use of this principle is a pneumatic muscle. For a cylinder with a constant diameter the reinforcement angle is constant as well and is 54. 7º and this also known as the magic angle or neutral angle. The neutral angle is the angle where a structure is in equilibrium. For a cylinder this is 54. 7º, but for a complex shape like a bellows which has a varying radius over the length of the product. In other words, for complex shapes there is not one magic angle, to obtain a reinforcement structure with isotensoidal loading the geometry of the complex shape must follow an isotensoid meridian profile. The mil fabric reinforcement can be applied on the products with different processes. For straight hoses the most used processes are braiding, spiralling, knitting and wrapping, the first three processes have in common that multiple strands of fibres are applied to the product simultaneously on a predetermined pattern in an automated process
20.
Wayback Machine
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The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
21.
Types of road
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Many types of road exist around the world, all of which are thoroughfares which can be used by motorized traffic. Roads are not necessarily available for use by the public without permission, highways are available to the public. In places the highway is reserved for high capacity roads. Different terms are used in different countries for broadly the same design, for example, freeway USA, motorway UK and autobahn Germany all of which are broadly similar. A road can consist of one or more carriageways
22.
Limited-access road
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The degree of isolation from local traffic allowed varies between countries and regions. The precise definition of these terms varies by jurisdiction, the first implementation of limited-access roadways in the United States was the Bronx River Parkway in New York, in 1907. The New York State Parkway System was constructed as a network of high-speed roads in, the first limited access highway built is thought to be the privately built Long Island Motor Parkway in Long Island, New York. The Southern State Parkway opened in 1927, while the Long Island Motor Parkway was closed in 1937 and replaced by the Northern State Parkway, in the United States, the national Manual on Uniform Traffic Control Devices uses full control of access only for freeways. This definition is used by some states, some of which also restrict freeways only to motor vehicles capable of maintaining a certain speed. Some other states use controlled access to mean a higher standard than limited access, while Australias larger capital cities feature controlled-access highway networks, the smaller metropolitan areas mostly rely on limited-access highways for high-speed local traffic. In South Australia the terms expressway and freeway can be synonymous, the Southern and Northern Expressways are both controlled-access highways. However, perhaps confusingly, the Port River Expressway is a limited-access highway, dual carriageways that connect capital cities and regional centres, such as the M31 Hume Highway between Sydney and Melbourne, are almost all limited-access highways. In spite of this, freeway terminology is used on signage for most regional limited access highways in the state of Victoria, the Expressway Network of the Peoples Republic of China is the longest highway system in the world. The network is known as National Trunk Highway System. As of 2011, the length is 85,000 kilometres. Expressways in China are a recent addition to a complex network of roads. Chinas first expressway was built in 1988, until 1993, very few expressways existed. The network is expanding rapidly after 2000, in 2011,11,000 kilometres of expressways were added to the network. The Philippines has many expressways and highways particularly concentrated on the island of Luzon, the country currently has 6 completed and available expressways and 8 major highways including the Pan-Philippine Highway also known as Asian Highway 26. The Expressways of Pakistan are a network of multiple-lane, high-speed highways in Pakistan and they are one class lower than the countrys motorways and are usually upgraded versions of the national highways. The total length of Pakistans expressways is 260-kilometre as of November,2016, around 770-kilometre of expressways are currently under construction in different part of country. Most of these expressways will be complete between 2017 and 2020, Expressways in Taiwan may be controlled-access highways similar to National Freeways or limited-access roads
23.
Controlled-access highway
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A controlled-access highway is a type of highway which has been designed for high-speed vehicular traffic, with all traffic flow and ingress/egress regulated. Common English terms are freeway, motorway and expressway, other similar terms include Interstate and parkway. Some of which may be limited-access highways, although this term can refer to a class of highway with somewhat less isolation from other traffic. In countries following Vienna convention, the motorway qualification implies they are forbidden for walking or parking, a controlled-access highway provides an unhindered flow of traffic, with no traffic signals, intersections or property access. They are free of any at-grade crossings with roads, railways, or pedestrian paths. Entrances and exits to the highway are provided at interchanges by slip roads, on the controlled-access highway, opposing directions of travel are generally separated by a median strip or central reservation containing a traffic barrier or grass. Elimination of conflicts with other directions of traffic dramatically improves safety and capacity, controlled-access highways evolved during the first half of the 20th century. Italy opened its first autostrada in 1924 connecting Milan to Varese, Germany began to build its first 30-kilometre autobahn controlled-access highway without speed limits in 1932 between Cologne and Bonn. It then rapidly constructed a system of such roads in anticipation of their use in the Second World War. The first North American freeways opened in the New York City area in the 1920s, Britain, heavily influenced by the railways, did not build its first motorway, the Preston By-pass, until 1958. Most technologically advanced nations feature a network of freeways or motorways to provide high-capacity urban travel, or high-speed rural travel. Many have a national-level or even international-level system of route numbering, exit is marked with another symbol. The definitions of motorway from the OECD and PIARC are almost identical, british Standards Motorway, Limited-access dual carriageway road, not crossed on the same level by other traffic lanes, for the exclusive use of certain classes of motor vehicle. ITE Freeway, A divided major roadway with full control of access and this definition applies to toll as well as toll-free roads. Freeway A, This designates roadways with greater complexity and high traffic volumes. Usually this type of freeway will be found in areas in or near the central core. Freeway B, This designates all other divided roadways with full control of access where lighting is needed, principal arterials may cross through urban areas, serving suburban movements. The traffic is characterized by high speeds and full or partial access control, other roads leading to a principal arterial are connected to it through side collector roads
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Dual carriageway
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A dual carriageway is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation. Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, a road without a central reservation is a single carriageway regardless of the number of lanes. Dual carriageways have improved road traffic safety over single carriageways and typically have speed limits as a result. In some places, express lanes and local/collector lanes are used within a system to provide more capacity. A very early example of a dual carriageway was the Via Portuensis, in 1907 the Long Island Motor Parkway opened, and roughly 20% of it featured a semi-dual-carriageway design. The New York City Belt Parkway system, which was built between 1907 and 1934, also pioneered the same design, however the majority of it featured concrete or brick railings as lane dividers instead of grass medians. In 1924 the first Italian autostrada was opened running 55 km from Milan to Varese and it featured a broad road bed and did not feature lane dividers except near cities and through the mountains. The London end of the Great West Road became Britains first dual carriageway when it was opened in 1925 by King George V, in 1927 the Rome bypass was opened. It ran 92 km bypassing Rome to the east, almost the entire length featured a dual-carriageway design. In the early 1930s it was extended all the way to Naples. Most of the routing was destroyed by the Allies in the World War II. By 1930 several US and European cities had built dual-carriageway highways, in 1932 the first German autobahn opened between Cologne and Bonn. It ran 21 km and became a precedent for future highways, although it, like the first autostrada, did not feature a dual-carriageway design, it inspired the mass construction of future high-speed roadways. During the 1930s, Germany, Italy, and the Soviet Union began construction of a network of dual carriageway expressways. By 1942, Germany had over 3,200 km of dual carriageway roads, Italy had nearly 1,300 km, opened to traffic in 1940, the 160-mile-long Pennsylvania Turnpike was the first rural dual carriageway built in the United States. By 1955 several states had built dual carriageway freeways and turnpikes, completed in 1994, the major highway system links all the major cities of the United States. In the UK, although the dual carriageway applies to any road with physically separated lanes. Such major dual carriageways usually have two lanes of traffic in each direction, with the lane nearest the centre being reserved for overtaking, occasionally dual carriageways have only one lane in each direction, or more than two lanes each way
25.
Highways in Australia
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Prior to European settlement, the earliest needs for trade and travel were met by narrow bush tracks, used by tribes of Indigenous Australians. The formal construction of roads began in 1788, after the founding of the colony of New South Wales, similar road networks were established in the other colonies of Australia. Local government authorities, often known as Road Boards, were established to be primarily responsible for funding and undertaking road construction. The early 1900s saw both the widespread use of motorised transportation, and the creation of state road authorities in each state. These authorities managed each states road network, with the arterial roads controlled and maintained by the state. The federal government became involved in funding in the 1920s. The depression of the 1930s slowed the funding and development of the road network until the onset on World War II. Supply roads leading to the north of the country were considered vital, resulting in the construction of Barkly, Stuart, in 1974, the federal government assumed responsibility for funding the nations most important road links, between state and territory capitals cities, which were declared National Highways. Some sections of the 16, 000-kilometre-long National Highway system were no more than dirt tracks, the network was gradually improved, and by 1989, all gravel road sections had been sealed. National Routes were assigned to significant interstate routes which, both now and in the future, comprise the more important arteries of road communications throughout Australia in all its aspects. East-west routes were planned to have numbers, increasing from south to north, while north-south routes would have odd numbers. National Route 1 would be an exception, as a route along the coastline of Australia. A state route marking systems was designed to supplement the system, for inter-regional. Each state could choose their own numbering scheme, as long as National Route and State Route numbers werent duplicated in the same state, or nearby routes in another state. When the National Highway system was introduced, National Routes along it became National Highway routes with the same numbers, during the 1990s, planning began for a new alphanumeric route system. Alphanumeric routes have been introduced in most states and territories in Australia, the earliest needs for trade and travel were met by narrow bush tracks, used by tribes of Indigenous Australian prior to European settlement. The formal construction of roads began in 1788, after the founding of the colony of New South Wales and these roads were little more than cleared paths, constructed without grading, drainage systems, and road surfaces. By the end of his term in 1822 the colony had a network of three roads, with the Great Western Road as the most important link, traversing the Blue Mountains from Sydney to Bathurst
26.
Brazilian Highway System
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The Brazilian Highway System is the highway system of Brazil. As of 2010, the system consists of almost 2 million kilometers of roads, the national speed limit for cars driving in non-urban roads is 110 km/h unless otherwise stated, regardless of the road design, weather or daylight. Brazilian Regional highways are named YY-XXX, where YY is the abbreviation of the state where the highway is running in, Brazilian National highways are named BR-XXX. National highways connect multiple states altogether, are of importance to the national economy and/or connect Brazil to another country. The meaning of the numbers are, 000-099 - it means that the highway runs radially from Brasília and it is an exception to the cases below. 100-199 - it means that the runs in a south-north way 200-299 - it means that the highway runs in a west-east way 300-399 - it means that the highway runs in a diagonal way. Highways with odd numbers run northeast-southwest, while even numbers run northwest-southeast, 400-499 - it means that the highway interconnects two major highways. Often Brazilian highways receive names, but continue to have a YY/BR-XXX name, see highway system of São Paulo for numbering designation for São Paulo state roads, also used in some other states. It would be the major accomplishment on the area for years, most of these roads follow poor standards, but they created links where there were none. The military presidents would mostly follow these standards to expand the system. The exceptions would be the modern highways built by the São Paulo State Government, in the same year, the Via Dutra was modernized, allowing a fast and modern trip between São Paulo and Rio de Janeiro. The country would reach 200,000 km paved in 2000, between 1995 and 2005 three major highways were modernized. Until then, most of these highways were known for their high mortality due to traffic accidents. In this region, highways, when they are present, generally are unpaved, Manaus, for example, has no major paved highways connecting it to any other city but Boa Vista in the north. Due to the growth and the associated traffic increase, the Government has started the construction and adaptation of main road sections into motorways. Nowadays, the Government and the sector are planning to duplicate thousands of kilometers. All major Brazilian paved highways have toll roads, in the 1990s, many state governments decided to privatize public-controlled paved highways, in order to generate extra income to the states budget. These governments argued that funding would make problematic highways much better
27.
Expressways of China
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The expressway network of China is an integrated system of national and provincial-level expressways in China. It is the worlds largest expressway system by length, having surpassed the length of the American Interstate Highway System in 2011. Between the end of 2014 and 2015, the length of the network grew from 111,950 kilometres to 123,000 kilometres meaning 11,050 kilometres of expressway were built in 2015 alone. This backbone is known as the 71118 network, in addition, the provincial-level divisions of China each have their own expressway systems. Expressways in China are a recent addition to the transportation infrastructure in the country. Previously, the road network consisted of a system of at-grade China National Highways. Chinas first expressway, the Shanghai–Jiading Expressway, opened in October 1988 and this 17.37 kilometres expressway now forms part of Shanghais expressway network. The early 1990s saw the start of the countrys massive plan to upgrade its network of roads, in 1999, the length of the network exceeded 10,000 kilometres in length. Many of the major expressways parallel routes of the older China National Highways, prior to the 1980s, freight and passenger transport activities were predominantly achieved by rail transport rather than by road. The 1980s and 1990s saw a trend toward roads as a method of transportation. In 1978, rail transport accounted for 54. 4% of the freight movement in China. By 1997, road transports share of freight movement had increased to 13. 8% while the railways share decreased to 34. 3%. Similarly, roads share of transport increased from 29. 9% to 53. 3% within the same time period. The shift from rail to road can be attributed to the development of the expressway network in China. On 7 June 1984, Chinas expressway ambitions began when construction of the Shenyang–Dalian Expressway began between the cities of Shenyang and Dalian, the expressway is now part of the longer G15 Shenyang–Haikou Expressway. Later that year, construction began on the Shanghai–Jiading Expressway in the city of Shanghai, the Shanghai–Jiading Expressway opened on 31 October 1988, becoming the first completed expressway in China. This replaced the proposal for five north-south and seven east-west core routes. The total costs of the expressway network are estimated to be 2 trillion yuan
28.
Highways in Croatia
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Highways in Croatia are the main transport network in Croatia. The Croatian classification includes several classes of highways, The main motorways are named A accompanied by one or two digits, by and large they are toll highways with a ticket system. Expressways are limited-access roads with grade-separated intersections and by and large an increased speed limit without tolling and they are similar to motorways, but arent always dual carriageway, they have no emergency lanes, and their speed limit is always lower. They either have standalone designations or are parts of state routes. Roads dedicated for vehicles, which is a category for highways which are limited-access roads, usually similar to multiple-lane motorways/expressways. It has no naming convention, only a dedicated traffic sign. An example is the Jadranska Avenue in Zagreb, designated as county road. County roads always are marked by letter Ž and a four digit number, the lowest classification comprises local roads, marked by letter L and a five digit number. Road operators differ according to the system, The designated motorways are operated by four different concessionaires. The state roads are maintained almost exclusively by Hrvatske ceste, while the county, the road maintenance agencies are governed by various laws issued by the Parliament as well as bylaws issued by the Ministry of Transport. The primary high-speed motorways are called autoceste, and they are defined as roads with at least three lanes in each direction and a limit of not less than 80 kilometres per hour. They are marked with a road sign, similar to the road sign depicting a motorway/autoroute/autobahn in other parts of Europe. In Croatia this sign has green background, the national speed limit on an autocesta, effective in case no other speed limits are present, is 130 kilometres per hour, with a legal tolerance of 10% on speeds over 100 km/h. The term autocesta is sometimes translated by Croatians simply as highway, which can be confusing because a highway can be any road. The Croatian motorway network is 1,313.8 kilometres long, motorways in Croatia are defined by the Ministry of Sea, Transport and Infrastructure. The same applies to names of the interchanges and rest areas. Likewise, the same legislation defines the origin of motorway chainages - at the northern or the western terminus of the motorway -, generally, the motorways in Croatia are developed and maintained by the state-owned company Hrvatske autoceste. A major reason for the motorway construction mania of the 2000s is a previous political halt of the major Croatian highway project, todays A1, in the 1970s and 1980s under former Yugoslavia
29.
Highways in the Czech Republic
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Highways in the Czech Republic are no longer divided into motorways and expressways as the category of expressways has been abolished by 31 December 2015. This concerned especially the expressway R35 between Liberec and Turnov which has classified as of 1 January 2016 as a road for motorcars. The motorways are managed by the state-owned Road and Motorway Directorate of the Czech Republic – ŘSD ČR, the ŘSD currently manages and maintains 1,250 km of motorways, whose speed limit is of 130 km/h or 80 mph. The present-day national motorway network is due to be of about 2,000 km before 2030, generally said, a motorway road sign means that a toll vignette is obligatory. Only sections not subject to vignette are designated with a road sign. As of 2017, the following sections are subject to the time-based fee for motorcars up to 3. As of 1 January 2010, this also to vehicles over 3.5 tons. There is a public discussion on imposition of electronic toll for all cars. The definitive route, including a Prague ring motorway, was approved shortly after the Munich Agreement on 4 November 1938 for a speed limit of 120 km/h. However, only a construction of the route within Bohemia and Moravia was initiated and it still sporadically appears in some current Czech motorway plans. On 1 December 1938 the Nazi Germany had already initiated a construction of so-called Sudetenautobahn in the route Streitau – Eger – Carlsbad – Lobositz – Leipa a. d. The technical parameters of motorways were adjusted to those of German Reichsautobahn as Czech motorways should be integrated within the German Reichsautobahn network. The project for the first segment Prague - Lužná was ready in January 1939, the construction in Bohemia from Prague on began on 2 May 1939, with switch to right-hand traffic in Bohemia and Moravia already gone without a hitch. The motorway should have reached Brno in 1940, but building materials, the construction in the route of approx. 77 km from Prague towards Brno advanced notably when a prohibition of all civil constructions by German authorities came into force in 1942, the construction sites of the partly inaugurated construction of the Sudetenautobahn were completely abandoned, as well as that of the Breslau - Vienna motorway. The latter was, however, incorporated in some plans as a future connection motorway between Brno and the D35 motorway, the construction was solemnly inaugurated on 8 September 1967. Due to a change of parameters, some bridges finished before 1950 were replaced. The Prague - Brno motorway, initiated on 2 May 1939, reached Brno in 1980, the pace of construction of highways has always been rather slow up to the present days
30.
Autobahn
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The Autobahn is the federal controlled-access highway system in Germany. The official German term is Bundesautobahn, which translates as federal motorway, the literal meaning of the word Bundesautobahn is Federal Auto Track. German autobahns have no federally mandated speed limit for some classes of vehicles, however limits are posted in areas that are urbanized, substandard, accident-prone, or under construction. On speed-unrestricted stretches, a speed limit of 130 kilometres per hour applies. A2008 estimate reported that 52% of the network had only the advisory speed limit, 15% had temporary speed limits due to weather or traffic conditions. Measurements from the German State of Brandenburg in 2006 showed average speeds of 142 km/h on a 6-lane section of autobahn in free-flowing conditions. Germanys autobahn network has a length of about 12,993 kilometres in 2016. Longer similar systems can be found in the United States and India, only federally built controlled-access highways with certain construction standards including at least two lanes per direction are called Bundesautobahn. They have their own, white-on-blue signs and numbering system, in the 1930s, when construction began on the system, the official name was Reichsautobahn. Various other controlled-access highways exist on the federal, state, district and these highways are considered autobahnähnlich and are sometimes colloquially called Gelbe Autobahn because most of them are Bundesstraßen with yellow signs. Some controlled-access highways are classified as Bundesautobahn in spite of not meeting the construction standard. Nearly all exits are to the right, in the postwar years, a thicker asphaltic concrete cross-section with full paved hard shoulders came into general use. The top design speed was approximately 160 km/h in flat country, a flat-country autobahn that was constructed to meet standards during the Nazi period, could support the speed of up to 150 km/h on curves. The current autobahn numbering system in use in Germany was introduced in 1974, all autobahns are named by using the capital letter A, which simply stands for Autobahn followed by a blank and a number. The main autobahns going all across Germany have a single digit number, shorter autobahns that are of regional importance have a double digit number. The first digit used is similar to the system above, depending on the region, east-west routes are always even-numbered, north-south routes are always odd-numbered. The north-south autobahns are generally numbered using odd numbers from west to east, that is to say, similarly, the east-west routes are numbered using even numbers from north to south. One project was the private initiative HaFraBa which planned a car only road crossing Germany from Hamburg in the North via central Frankfurt am Main to Basel in Switzerland
31.
Highways in Greece
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Highways in Greece are generally organized so that the odd numbered highways are of north-south alignment and even numbered highways are of east-west alignment. The designation of some important roads of Greece as national was decided by a 1955 decree, in 1998, a survey of the Hellenic Statistical Authority defined some new national roads that were constructed after the 1963 decision. Furthermore, motorway numbers in Greece are different and irrelevant to other highways numbers, for example, Motorway 6 refers to the Attiki Odos motorway, while GR-6 refers to a different road. Greeces motorway network has been extensively modernised throughout the 2000s and part of it is still under construction, most of it is expected to be completed by early 2017. There are a total of 10 main routes throughout the Greek mainland and Crete, from which some feature numerous branches/auxiliary routes, most of the route has been upgraded to motorway standards, expept for 25 kilometres through the Tempe Valley. As of summer 2008, works were in progress around the Malian Gulf, most of the route around the bay, was completed in April 2008, but due to delays, the last part was finally given to traffic on March 16,2015. At Tempe valley, works started in 2008, in order to be completed around 2012 and this part will include 11 km of tunnels, made mostly for environmental protection and, of course, road safety. Furthermore, the section between Thessaloniki and Evzoni, is yet to be converted into motorway, but this is not planned to happen in the near future. The full length of motorway is around 553 km or 346 miles. Note that until recently, the P in PAThE referred to Patras, Motorway 11 is a branch of the A1, connecting it with the city of Chalcis. Motorway 12 is another branch of the A1, connecting it with the city of Volos, although it is a dual carriageway throughout its length, parts of it remain with traffic lights and not all sections of the branch are up to motorway standards. Ongoing construction has been happening to upgrade it to such and it also includes a tunnel near the village of Goritsa. Motorway 13 is a branch of the A1, from Thiva to Elefsina, connecting it with the Olympia Odos motorway. Motorway 2, colloquially referred to as the Egnatia Odos, is a new motorway starting at the port of Igoumenitsa, specifically, there are auxiliary routes to Albania and Bulgaria, with the main route leading to Turkey. The Republic of Macedonia is accessed through the A1, as described above, another auxiliary route runs close to the Evros river in the prefecture of the same name, reaching a point where Greeces, Turkeys and Bulgarias borders meet. Some of those routes are not motorways, but typical 2-lane highways. The project, was completed in 2009, with the length of the route being 670 kilometres or 416 miles. As it passes through the eastern periphery of Thessaloniki the A25 becomes part of the Thessaloniki Inner Ring Road, Motorway 27 is another branch of the A2, at Kozani which leads towards Ptolemaida and from there to Florina and the border crossing with the Republic of Macedonia
32.
Indian road network
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India has a road network of over 5,472,144 kilometres as on 31 March 2015, the second largest road network in the world. However, qualitatively Indias roads are a mix of modern highways and narrow, unpaved roads, as on 31 March 2015,61. 05% of Indian roads were paved. Adjusted for its population, India has less than 3.8 kilometres of roads per 1000 people. In terms of quality, all season,4 or more highways, India has less than 0.07 kilometres of highways per 1000 people. These are some of the lowest road and highway densities in the world, for context, United States has 21 kilometres of roads per 1000 people, while France about 15 kilometres per 1000 people – predominantly paved and high quality in both cases. In terms of all season,4 or more highways, developed countries such as United States. India in its past did not allocate enough resources to build or maintain its road network and this has changed since 1995, with major efforts currently underway to modernize the countrys road infrastructure. According to the CIA World Factbook, as of 2015, India had about 96,000 kilometers of highways and expressways. Major projects are being implemented under the National Highways Development Project, the Government of India is attempting to promote foreign investment in road projects. The first evidence of development in the Indian subcontinent can be traced back to approximately 2800 BC from the ancient cities of Harrapa. Ruling emperors and monarchs of ancient India had constructed roads to connect the cities, archaeological excavations give us fresh information about road connectivity in ancient India. The Grand Trunk Road was built by Sher Shah Suri in 1540-45 connecting Sonargaon near Dhaka in Bangladesh with Peshawar in modern-day Pakistan linking several cities from in India, India inherited a poor road network infrastructure at the time of its independence in 1947. Beyond that, between 1947 and 1988, India witnessed no new projects, and the roads were poorly maintained. Predominantly all roads were single lane, and most were unpaved, India had no expressways, and less than 200 kilometers of 4-lane highways. In 1988, an entity called the National Highways Authority of India was established in India by an Act of Parliament. The Act empowered this entity to develop, maintain and manage Indias road network through National Highways, however, even though the Authority was created in 1988, not much happened till India introduced widespread economic liberalization in the early 1990s. Road transport is vital to Indias economy and it enables the countrys transportation sector to contribute 4.7 percent towards India’s gross domestic product, in comparison to railways that contributed 1 percent, in 2009–2010. Road transport has gained its importance over the years despite significant barriers and inefficiencies in inter-state freight and passenger movement compared to railways, the government of India considers road network as critical to the countrys development, social integration and security needs of the country
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High-quality dual carriageway
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A High-quality dual carriageway is a category of road in Ireland. It is a dual carriageway road type built to near motorway standards. High-quality dual carriageways have full grade-separated access and do not have junctions with minor roads, such roads in the Republic of Ireland have been built as part of the 2000-2006 and 2007-2013 National Development Plans, including interurban routes from Dublin to other cities. While HQDCs or roads of similar type exist in a number of countries this article concentrates mainly on such roads in Ireland, standard motorways,52,000 vehicles AADT - annual average daily traffic. The road type is all-purpose dual carriageway, but with the specifications as motorway, a carriageway width of 7 metres. HQDCs are limited access and not intended to have junctions with minor roads, junctions with major roads are grade-separated and to motorway standards. All HQDCs in Ireland currently form part of primary roads. There are exceptions however, as speed limits may now be specified for sections of road if the local authority passes a by-law. For example, a section of the N1 from the end of the M1 motorway has a 120 km/h speed limit. Signage on Irish HQDCs is similar to signage used on Irish motorways, however signage on HQDCs uses a green background instead of the blue background used on Irish motorway signage. In the event of an HQDC being a road, black text on a white background would be used instead. Also, as on other roads, signs should include patches for roads of other classifications. As high-quality dual carriageways are not motorways, they do not need to conform to motorway regulations, HQDCs have a hard shoulder marked with a broken yellow line, rather than the solid yellow line used to mark the hard shoulder of an Irish motorway. Also, L-Drivers, who are not permitted to drive on motorways can do so on high-quality dual carriageways, HQDCs are a road type, not a classification, and the normal rules and regulations applying to all-purpose roads apply on HQDCs. The M9 Carlow bypass was built with lay-bys as it was originally to be built as an HQDC section of the N9 route, the lay-bys were removed after the road was reclassified as a motorway. Lay-bys on other HQDCs which were reclassified as motorways were restricted to authorised vehicles only and are likely to be used mainly by Garda Síochána patrol vehicles, the standard speed limit for cars on Irish motorways is 120 km/h. The standard speed limit on roads is 100 km/h. A number of authorities have passed special speed limit by-laws permitting dual carriageways in their administrative area to carry motorway speed limits of 120 km/h
34.
Autostrade of Italy
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The Autostrade are roads forming the Italian national system of motorways. The total length of the system is about 6,758 kilometres, in North and Central Italy this is mainly as tollways, with the biggest portion in concession to the Atlantia group which operates some 3,408 km. Italy was the first country in the world to build motorways, i. e. fast roads, the Milano-Laghi motorway was devised by Piero Puricelli, a civil engineer and entrepreneur. He received the first authorization to build a public-utility fast road in 1921, by the end of the 1930s, over 400 kilometers of multi- and dual-single-lane motorways were constructed throughout Italy, linking cities and rural towns. Italys autostrade have a speed limit of 130 km/h for cars. Limits for other vehicles are lower, in 2016, no road was taking advantage of this possibility. The first speed limit, to 120 km/h, was enacted in November 1973 as a result of the 1973 oil crisis, the designation A2 is to be used instead of A3 for the A3 Naples - Campo Calabro in future and the A3 will be retired. After a link was built bypassing Rome, the designation A2 was withdrawn, the residual connections to the Grande Raccordo Anulare were designated as raccordi. Until 1973, the designation A17 referred to the current A16, and this is a list of tangenziali classified as autostrada. Bretelle, diramazioni or raccordi are generally connections between two motorways, or connections between motorways and important cities without a motorway. They have the number as one of the two autostrade linked, a combination of the numbers of the two autostrade linked, or the number of the main autostrada. Important alpine tunnels are identified by the capital letter T followed by a single digit number, currently there are only three T-classified tunnels, Mont Blanc Tunnel, Great St Bernard Tunnel and Frejus Road Tunnel. Tunnels that cross the border between Italy and France or Switzerland, are treated as motorways, although they are not proper motorways, the code T3 was once assigned to the Bargagli-Ferriere Tunnel in Ligurian Appennines before it was reclassified as SP226. RA stands for Raccordo autostradale, a short spur route that connects an autostrada to a nearby city or tourist resort not directly served by the motorway. These spurs are owned and managed by ANAS, some spurs are toll-free motorways, but most are type-B or type-C roads. All RA have separate carriageways with two lanes in each direction, generally, they do not have an emergency lane. Access restrictions on highways are exactly the same as autostrade. Signage at the beginning and the end of the highways is the same, the general speed limit on strade extraurbane principali is 110 km/h
35.
Roads in Portugal
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Roads in Portugal are defined by National Road Plan, which describes the existing and planned network of Portuguese roads. The present plan in force is the 2000 National Road Plan and it has replaced the previous PRN1985, which itself had replaced the PRN1945. The Portuguese road infrastructure is considered the best in Europe and the second best in the World by the World Economic Forum in its Global Competitiveness Report for 2014–2015. The scenic road between Peso da Régua and Pinhão, in Northern Portugal, was considered the World Best Driving Road and this road is a section of the N222 which route follows the Douro Valley. The precognized network was classified in 1850 as estradas and caminhos, with the estradas being classified as 1st, caminhos were routes of mere local interest. In 1862, the roads were classified as 1st class roads or estradas reais, 2nd class roads or estradas distritais, the estradas reais were those with direct or indirect origin in Lisbon) and the estradas municipais were those managed by the municipalities. With the abolition of the Monarchy in 1910, the estradas reais were renamed estradas nacionais, in 1913, the Law of 22 February establishes a commission to study the new classification of the roads and presents the guidelines to proceed to that classification. However, The new classification and road plan would only be established 13 years later, both the 1st and 2nd class roads would be designated estradas nacionais, with the term estrada distrital disappearing. They would be designated EN xx-x, in a way that the number before the - designated the number of the road and this plan established 23 roads of 1st class and 112 roads of 2nd class. The General Plan of National Roads would be reviewed and definitely approved by the Decree nº16075 of 30 September 1928. The preliminary report was clear to state that from the 16000 km of the road network,4000 km were to be completed. The roads were then reclassified as estradas nacionais, estradas municipais and caminhos públicos, in 1933, the whole network totalized 16900 km. By that date, the National and Municipal network, comprised 20500 km, branch roads, emerging from a determinated road, which was identified in the X factor, with a number of order according to point of origin, identified in the Y factor. The road with most branch roads was N1, originally with 16 roads, the National Roads Statutes were subsequently approved in 1949. The first urban highways have been also in the 1960s. The road classes where identified by colour codes, red for 1st class, blue for 2nd class, green for 3rd class, yellow for municipal roads and these colors were applied in the bases of the location markers and occasionally in the background of the road numbers. The numbering distribution for main roads was according to the importance of its route in the network, and for N101 and over were numbered in a North to South growing fashion. The extension of the roads had no relation with its class, with existing 3rd class roads more than 100 km long, the longest road of the 1945 Plan was N2, connecting Chaves to Faro, extending for 738 km
36.
Highways in Spain
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The Spanish motorway network is the eleventh largest in the world by length. As of 2013, there are 16,583 km of High Capacity Roads in the country, there are two main types of such roads, autopistas and autovías, which historically differed in the strictness of the standards they are held up to. The distinction between two kinds of high capacity roads is mainly a historical one, seldom with practical consequences for most, both kinds are divided highways with full access control and at least two lanes per direction. General speed limits for both are mandated by the Spanish Traffic Law as 60–120 km/h, though there are groups that ask for the latter to be raised to 140 km/h, specific limits may be imposed based on road, meteorologic or traffic conditions. Autopistas are specifically reserved for travel, so all vehicles not able to sustain at least 60 km/h are banned from them. Thus, they may not be an upgrade to an older road, many, but not all, autopistas are toll roads, which also mandates an alternate toll-free route under the Spanish laws. An example is the AP-2 toll autopista, which links Zaragoza with Barcelona through the Monegros desert, in this case, the alternative is the N-II, the national road that preceded the A-2 autovía. On the other hand, autovías are usually upgrades from older roads, in general, slow vehicles like bicycles and agricultural machinery are allowed under certain restrictions so as to not disrupt the traffic excessively or cause any danger. Furthermore, an autovía will most likely follow the road very closely, only deviating from it to avoid direct penetration into towns. Thus, the road usually serves as the base for one of the two directions of the new autovía, which means the turns can be steeper than in autopistas. All in all, an autovía, Allows traffic banned from an autopista, however, if the autovía is built as a new road instead of an upgrade to an older one, this traffic may be banned too. May have little to no shoulders, which are marked with a solid line instead of the broken line of a transitable shoulder. May have acceleration and deceleration lanes that are shorter than those of autopistas. May have tighter turns and steeper gradients than an autopista is allowed, if space-constrained, it may even have bus stops on a service lane in the autovía itself, as opposed to requiring them to be placed on a service lane physically separated from the main road. In those cases, the freeway would make a semi-loop called a variante around the town, new autovías usually have perfectly normal acceleration and deceleration lanes, very safe turns and transitable shoulders. Usually, the DGC manages all road maintenance, but in the case of the tolled autopistas, for example, the M-50 is further from the city of Madrid than the M-40. City access motorways are named similarly to beltways, like TO-21 for a leaving the A-40 towards Toledo. Tolled roads add a P before the dash, and must be identified as such in road signs
37.
Highway system in Taiwan
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As a general rule, the odd numbers represent north-south highways and even numbers represent east-west. The numbers increase moving west to east and north to south, major north-south provincial highways are indicated by a one-digit number. Special routes of a highway use the number, followed by a heavenly stem character. However, for English translation, these characters are replaced by letters in the alphabetical order and their design is heavily based on the Interstate Highway System of the United States. The first controlled-access highway, and a predecessor to the highways in Taiwan, was the MacArthur Thruway. Construction on the first modern highway, National Highway 1 began in 1971. The northern section between Keelung and Zhongli was completed in 1974, and the freeway was completed in 1978. It runs from the harbor city of Keelung to the southern harbor city of Kaohsiung. Construction began on the freeways in the late 1980s. The northern section of the second freeway between Xizhi and Hsinchu was completed in 1997. 1A Branch was extended to link No.3 Freeway at Yingge, Taipei, three other short freeways were built to link the two north-south freeways in Taichung County, Tainan County, and Kaohsiung County, respectively. The entire No.3 Freeway was completed in January 2004, to ease the congestion of No. The construction of a freeway connecting the Taipei metropolitan area and Yilan County began in 1991 and was completed in June 2006 and it includes a 12. 9-kilometre tunnel, which is the ninth-longest road tunnel in the world. An extension from Yilan County to Hualien County is planned, however, its construction is being delayed by environmental concerns. In 2013, the system was converted to a distance-based one. Tolls are no longer collected at toll booths but automatically by electronic toll collection. Every one tenth of a kilometer is marked on the freeway with Arabic numerals to indicate freeway mileage, that is, Exit numbers are based on the freeway mileage. There are four types of exit notification signs, the first notification sign appears two kilometers before the exit, providing the destination name and an Exit 2 km notice
38.
Roads in the United Kingdom
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Roads in the United Kingdom form a network of varied quality and capacity. Road distances are shown in miles or yards and UK speed limits are indicated in miles per hour or by the use of the speed limit symbol. Some vehicle categories have various lower maximum limits enforced by speed limiters, enforcement of UK road speed limits increasingly uses speed guns, automated in-vehicle systems and automated roadside traffic cameras. A unified numbering system is in place for Great Britain, whilst in Northern Ireland, the earliest specifically engineered roads were built during the British Iron Age. The road network was expanded during the Roman occupation, some of these survive and others were lost. New roads were added in the Middle Ages and from the 17th century onwards, certain aspects of the legal framework remain under the competence of the United Kingdom parliament. Although some roads have much older origins, the network was subject to development from the 1950s to the mid-1990s. From then, construction of roads has become controversial with direct action campaigns by environmentalists in opposition. In the UK, vehicles drive on the left and on multi-lane carriageways drivers are expected to keep to the left lane except when overtaking, in Great Britain, the Highway Code applies to drivers. In Northern Ireland, the Highway Code for Northern Ireland applies, UK speed limits are shown in mph. With a few exceptions, they are in multiples of 10, unless a lower speed limit is posted on a road, the national speed limit applies, which varies between class of vehicles and the type of road. In a built-up area, unless signs indicate otherwise, a limit of 30 miles per hour applies, other limits are shown in the table. For a road to be classed as a carriageway, the two directions of traffic flow must be physically separated by a central reservation. Roads in the UK are classified as M, A, or B roads, as well as categories of more minor roads, for internal purposes. These numbers follow a zonal system, there is no available explanation for the allocation of road numbers in Northern Ireland. The majority of the major routes are motorways, and are designed to carry long distance traffic. The next category is the A roads, which form the route network. A primary route is defined as, primary destinations are usually cities and large towns, to which, as a result of their size, a high volume of traffic is expected to go
39.
Numbered highways in the United States
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Highways in the United States are split into at least four different types of systems, Interstate Highways, U. S. Highways, state highways, and county highways. Highways are generally organized by a number or letter. These designations are generally displayed along the route by means of a highway shield, each system has its own unique shield design that will allow quick identification to which system the route belongs. Below is a list of the different highway shields used throughout the United States, Interstate highways are all constructed to precise standards, designed to maximize high-speed travel safety and efficiency. Interstate Highways also contain auxiliary routes, which are assigned a three-digit route number. All Interstate Highways are part of the National Highway System, a network of highways deemed essential to the defense, economy and this has led to the decommissioning and truncation of U. S. Highways that were formerly vital long-haul routes, such as U. S. Route 21, each state also has a state highway system. State highways are of varying standards and quality, some state highways become so heavily traveled they are built to Interstate Highway standards. Others are so lightly traveled that they are roads of low quality, many state highway markers are designed to suggest the geographic shape of the state or some other state symbol such as its flag. Most of the others are generically rectangular or some other neutral shape, the default design for state highway markers is the circular highway shield, which is how state highways are designated on most maps. Currently, five states—Delaware, Iowa, Kentucky, Mississippi, there are also numbered highways in Washington, D. C. and several U. S. territories. Likewise, they may vary in standards and quality. Some states may include a highway system to supplement the main one. For example, Texas established a system of roads to specifically improve access to rural areas. Nebraska has Connecting Link, Spur, and Recreation Highways to provide access to small towns, the Missouri supplemental route system was designed to provide access to most farm houses, schools, churches, cemeteries, and stores within the state. The final administrative level in some states is the county highway, as the name suggests, this type of road is maintained by a county. In Louisiana, parish roads exist in place of county highways, county roads vary widely from well-traveled multilane highways to dirt roads into remote parts of the county. Other highway systems include, Forest Highway, Highways connecting U. S. National Forests to the state highway systems
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Arterial road
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An arterial road or arterial thoroughfare is a high-capacity urban road. The primary function of a road is to deliver traffic from collector roads to freeways or expressways. As such, many arteries are limited-access roads, or feature restrictions on private access, though the design of arterial roads varies from country to country, city to city, and even within cities, they share a number of common design characteristics. For example, in cities, arteries are arranged in concentric circles or in a grid. Many jurisdictions also classify arterial roads as either principal or minor, in traffic engineering hierarchy, an arterial road delivers traffic between collector roads and freeways. For new arterial roads, intersections are often reduced to increase traffic flow, in California, arterial roads are usually spaced every half mile, and have intersecting collector and streets. The Traffic Engineering Handbook describes Arterials as being either principal or minor, both classes serve to carry longer-distance flows between important centers of activity. Arterials are laid out as the backbone of a network and should be designed to afford the highest level of service, as is practical. The construction and development of roads is achieved through two methods. By far the most common is the upgrading of an existing right-of-way during subdivision development, when existing structures prohibit the widening of an existing road however, bypasses are often constructed. Because of the placement and general continuity of arterial road corridors, sewers, water mains, conduits, in North America, traffic signals are used at most intersections. In Europe, large roundabouts are more commonly seen at the busier junctions, speed limits are typically between 30 and 50 mph, depending on the density of use of the surrounding development. In school zones, speeds may be reduced, likewise, in sparsely developed or rural areas. The width of arterial roads can range from four lanes to ten or more, some are divided at the center, while others share a common center lane, such as a contraflow lane or central turning lane. As with other types, environmental consequences derive from arterial roadways, including air pollution generation, noise pollution
41.
Collector road
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A collector road or distributor road is a low-to-moderate-capacity road which serves to move traffic from local streets to arterial roads. Unlike arterials, collector roads are designed to access to residential properties. Rarely, jurisdictions differentiate major and minor roads, the former being generally wider and busier. Collector roads can vary widely in appearance, some urban collectors are wide boulevards entering communities or connecting sections. Others are residential streets, which are wider than local roads. Small-scale commercial areas can be found on roads in residential areas. Key community functions such as schools, churches, and recreational facilities can often be found on collector roads, a collector road usually consists of a mixture of signaled intersections, roundabouts, traffic circles, or stop signs, often in the form of a four‑way stop. Two-way stops are used at intersections with local streets that favour traffic movement on the collector. In North America, a collector road normally has traffic lights at an intersection with an arterial road, traffic calming is occasionally used in older areas on collector roads as well. Collector roads can originate in different ways. Most often, they are planned within a suburban layout and built expressly for that purpose, occasionally, UK Government Planning Portal, Glossary, D
42.
County highway
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A county highway is a road in the United States and in the Canadian province of Ontario that is designated and/or maintained by the county highway department. Route numbering can be determined by each county alone, by agreement among counties. Any county-maintained road, whether or not it is given a signed number, many other systems are also used, some counties rather arbitrarily assign numbers to all maintained roads, but do not sign them at all or only sign them on standard street sign blades. County roads and highways vary greatly in design standards, funding, some county highways in urban areas are freeways or expressways. County roads that link communities or serve residential areas are often indistinguishable from state highways or residential streets, in rural areas, many county roads carry very little traffic, these roads are maintained less frequently. They may be in poor condition or not paved at all, in remote areas, county roads are made of sand, gravel, or graded earth, seeing only occasional foot, equestrian, and four wheel drive traffic. Some states, such as Wisconsin, use county highways in great numbers, linking major highways, in England and Wales, the term County Road means a road for which the county council is the highway authority. County highway shields are usually a yellow-on-blue pentagon, a black-on-white rectangle, some states, like Virginia and North Carolina, have no county highways in most of their counties, the state government maintains all roads in unincorporated areas. Others, like Connecticut, have no county routes because there is no government at the county level, alaskas county-equivalent boroughs maintain roads in unincorporated areas but none are numbered, Louisianas county equivalents are parishes, and, accordingly, have parish routes. Ohios county roads vary widely in construction, signage, and naming from county to county, in Minnesota, some county roads are known as County state aid highways. These roads are constructed and maintained by counties, but they are eligible for funding from the County State Aid Highway Fund, differences in signage between CSAH routes and other county roads depends on the county. Some counties, such as Stearns County, delineate between the two by using the standard blue pentagon shield for CSAH routes and Minnesotas normal white square shield for other county routes. Most county roads in Minnesota are designated with numbers, although a few non-CSAHs in Dodge County utilize letters instead, a few roads that cross county borders are also signed with an inter-county designation and a letter, but this system is not shown on most maps. In the United States, county highways are denoted in various ways, in states like Wisconsin, county highways are marked with letters—in Wisconsin with 1 to 3 letter combinations. Wisconsins county highways are frequently and clearly marked at most intersections, because the county names are non-exclusive, the state has many county roads with similar or identical names. These highways are marked at the beginning of the highway and marked occasionally throughout the route. In Iowa, county roads are marked with a single letter, the latter generally use numbers in the 600-series with some counties having routes in the 700s along with one route in the 800s. Two counties, Bergen and Monmouth, along some routes in Ocean County, have routes outside this range with 1- or 2-digit numbers along with some numbers in the 100s
43.
Local-express lanes
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Where highway ramps between express and local/collector lanes cross over another this is commonly known as braided ramps. Given the considerable overall width of this design, new suburban freeways are often designed with interchanges spaced far apart to avoid the need for parallel roadways. Ontario, Gardiner Expressway from Wickman Road to Royal York Road, Ontario, Highway 400 in York Region, from the Highway 7 interchange to south of Langstaff Road. Ontario, Highway 401 in Peel Region, Toronto and Durham Region, from Hurontario Street to Highway 427. From east of Kipling Avenue—serving the interchange with Highway 409—to west of Brock Road, Ontario, Highway 404 traffic from westbound 401 and eastbound 401 has a brief collector-express separation and ends just north of Sheppard Avenue East. Ontario, Highway 403 from the Highway 401/410 interchange to Cawthra Road, Ontario, Highway 427 from Queen Elizabeth Way/Gardiner Expressway to Highway 401 in Toronto. Ontario, Conestoga Parkway from Lancaster Street to Krug Street in Kitchener, Quebec, Autoroute 40 in Repentigny, Quebec. From Larochelle Blvd to Industrial Blvd, from Route 341 to Route 343. Nova Scotia, Nova Scotia Highway 118, in Dartmouth, Nova Scotia, California, State Route 180 at the State Route 41 and the State Route 168 interchanges. This interchange is unusual because it allows traffic to flow between State Route 41 and State Route 168, bypassing the State Route 180 main line. Google Maps California, Interstate 5 at the El Toro Y in Irvine, California, Interstate 10 west of downtown Los Angeles from the Harbor Freeway to Arlington Avenue. California, Interstate 805 in Chula Vista, between the H Street and E Street/Bonita Road exits, northbound, from Interstate 280 to Julian Street along Downtown San Jose. Southbound, from Interstate 280 to Alma Avenue, California, U. S. Route 101 near San Francisco International Airport Florida, I-110 in Pensacola becomes a controlled-access freeway between the Airport Blvd and the Bayou Blvd exits. Georgia, I-85 in Atlanta, old HOV lane became express lane in 2011,16 miles between Exit 94 and Exit 109. Illinois, The Dan Ryan Expressway and Kennedy Expressway, between 71st Street and Interstate 55, and between Ohio Street and the Edens and it is not a freeway, instead it is called a junior expressway. Grade-level intersections require vehicles to execute left hook turns from the local lanes. Illinois, Illinois Route 53 between Interstate 290 at its end and Kirchhoff Road follows a local-express format. Indiana, The Borman Expressway in Gary, indiana, The I-65/I-70 junction in Indianapolis
44.
Farm-to-market road
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In the United States, a farm-to-market road or ranch-to-market road is a state road or county road that connects rural or agricultural areas to market towns. These are better quality roads, usually a highway, that farmers and ranchers use to transport products to market towns or distribution centers, Texas established this system in 1949 to improve access to rural areas. The system consists primarily of paved, two-lane roads, though some segments are freeways and these roads are signed with route markers that contain the words FARM ROAD or RANCH ROAD, but the formal name is Farm to Market Road and Ranch to Market Road. The only road that uses the name Ranch Road is Ranch Road 1. As with other state-maintained highways in Texas, all Farm or Ranch to Market roads are paved, speed limits along these roads vary, but may be as high as 75 mph in rural areas, such as in Andrews and Pecos Counties. The first farm to market road in Texas was completed in January 1937 and it connected Mount Enterprise and the former community of Shiloh in Rusk County. The route was 5.8 miles long and was constructed at a cost of $48,015.12 and this route is now part of Texas State Highway 315. The first highway designated as FM1 was authorized in 1941. In 1945, the commission authorized a three-year pilot program for the construction of 7,205 miles of farm-to-market roadway, with cost shared equally by the state. As the program grew, efforts were made by legislators from rural areas, including State Senator Grady Hazlewood of Amarillo, neveille Colson and State Representative Dolph Briscoe. In 1962, the Texas legislature increased this amount to no less than $23 million annually, through federal fund matching, the system now accounts for over half of the mileage in the Texas Department of Transportation system. Guide signs designating these roads use a white rectangle with the abbreviation F. M. or R. M. As a result of growth and the expansion of urban areas, many Farm to Market and Ranch to Market roads that originally served rural areas now serve urban areas. Other than a few markers, such as on FM1315 near Victoria, most signs were not changed. However, though the Farm to Market and Ranch to Market designations remain in place on route signage, for example, the mileage of FM544 in the Plano area was transferred from FM544 to UR544 in 1995. As part of the highway system, Urban Roads are eligible for state maintenance, however, unlike rural Farm to Market and Ranch to Market roads. Farm to Market and Ranch to Market roads are numbered as a set of roads. There is not an FM and an RM with the route number
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