For other uses, see Asphalt (disambiguation). Note: The terms bitumen and asphalt are mostly interchangeable, Asphalt Maintenance in Northgate except where asphalt is used as a shorthand for asphalt concrete. Natural bitumen from the Dead Sea Refined asphalt The University of Queensland pitch drop experiment, demonstrating the viscosity of asphalt
Asphalt (/ˈæsˌfɔːlt, -ˌfɑːlt/), also known as bitumen (UK English: /ˈbɪtʃəmən, ˈbɪtjʊmən/, US English: /bɪˈt(j)uːmən, baɪˈt(j)uːmən/) is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used.
The primary use (70%) of asphalt Asphalt Driveway Paving Contractors Near Me is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs.
The terms “asphalt” and “bitumen” are often used interchangeably to mean both natural and manufactured forms of the substance. In American English, “asphalt” (or “asphalt cement”) is commonly used for a refined residue from the distillation process of selected crude oils. Outside the United States, the product is often called “bitumen”, and geologists worldwide often prefer the term for the naturally occurring variety. Common colloquial usage often refers to various forms of asphalt as “tar”, as in the name of the La Brea Tar Pits.
Naturally occurring asphalt is sometimes specified by the term “crude bitumen”. Asphalt Maintenance Its viscosity is similar to that of cold molasses while the material obtained from the fractional distillation of crude oil boiling at 525 °C (977 °F) is sometimes referred to as “refined bitumen”. The Canadian province of Alberta has most of the world’s reserves of natural asphalt in the Athabasca oil sands, which cover 142,000 square kilometres (55,000 sq mi), an area larger than England.
The word “asphalt” is derived from the late Middle English, in turn from French asphalte, based on Late Latin asphalton, asphaltum, which is the latinisation of the Greek ἄσφαλτος (ásphaltos, ásphalton), a word meaning “asphalt/bitumen/pitch” which perhaps derives from ἀ-, “without” and σφάλλω (sfallō), “make fall”. Crushed Asphalt Driveway the first use of asphalt by the ancients was in the nature of a cement for securing or joining together various objects, and it thus seems likely that the name itself was expressive of this application. Specifically, Herodotus mentioned that bitumen was brought to Babylon to build its gigantic fortification wall. From the Greek, the word passed into late Latin, and thence into French (asphalte) and English (“asphaltum” and “asphalt”). In French, the term asphalte is used for naturally occurring asphalt-soaked limestone deposits, and for specialised manufactured products with fewer voids or greater bitumen content than the “asphaltic concrete” used to pave roads.
The expression “bitumen” originated in the Sanskrit words jatu, meaning “pitch”, and jatu-krit, meaning “pitch creating” or “pitch producing” (referring to coniferous or resinous trees). The Latin equivalent is claimed by some to be originally gwitu-men (pertaining to pitch), and by others, pixtumens (exuding or bubbling pitch), which was subsequently shortened to bitumen, thence passing via French into English. From the same root is derived the Anglo-Saxon word cwidu (mastix), the German word Kitt (cement or mastic) and the old Norse word kvada.
In British English, “bitumen” is used instead of “asphalt”. The word “asphalt” is instead used to refer to asphalt concrete, a mixture of construction aggregate and asphalt itself (also called “tarmac” in common parlance). Bitumen mixed with clay was usually called “asphaltum”, but the term is less commonly used today.
In Australian English, “bitumen” is often used as the generic term for road surfaces.
In American English, “asphalt” is equivalent to the British “bitumen”. However, “asphalt” is also commonly used as a shortened form of “asphalt concrete” (therefore equivalent to the British “asphalt” or “tarmac”).
In Canadian English, the word “bitumen” is used to refer to the vast Canadian deposits of extremely heavy crude oil, while “asphalt” is used for the oil refinery product. Diluted bitumen (diluted with naphtha to make it flow in pipelines) is known as “dilbit” in the Canadian petroleum industry, while bitumen “upgraded” to synthetic crude oil is known as “syncrude”, and syncrude blended with bitumen is called “synbit”.
“Bitumen” is still the preferred geological term for naturally occurring deposits of the solid or semi-solid form of petroleum. “Bituminous rock” is a form of sandstone impregnated with bitumen. The tar sands of Alberta, Canada are a similar material.
Neither of the terms “asphalt” or “bitumen” should be confused with tar or coal tars.[further explanation needed]
See also: Asphaltene
The components of asphalt include four main classes of compounds:
The naphthene aromatics and polar aromatics are typically the majority components. Most natural bitumens also contain organosulfur compounds, resulting in an overall sulfur content of up to 4%. Nickel and vanadium are found at <10 parts per million, as is typical of some petroleum.
The substance is soluble in carbon disulfide. It is commonly modelled as a colloid, with asphaltenes as the dispersed phase and maltenes as the continuous phase. “It is almost impossible to separate and identify all the different molecules of asphalt, because the number of molecules with different chemical structure is extremely large”.
Asphalt may be confused with coal tar, which is a visually similar black, thermoplastic material produced by the destructive distillation of coal. During the early and mid-20th century, when town gas was produced, coal tar was a readily available byproduct and extensively used as the binder for road aggregates. The addition of coal tar to macadam roads led to the word “tarmac”, which is now used in common parlance to refer to road-making materials. However, since the 1970s, when natural gas succeeded town gas, asphalt has completely overtaken the use of coal tar in these applications. Other examples of this confusion include the La Brea Tar Pits and the Canadian oil sands, both of which actually contain natural bitumen rather than tar. “Pitch” is another term sometimes informally used at times to refer to asphalt, as in Pitch Lake.
Bituminous outcrop of the Puy de la Poix, Clermont-Ferrand, France
The majority of asphalt used commercially is obtained from petroleum. Nonetheless, large amounts of asphalt occur in concentrated form in nature. Naturally occurring deposits of bitumen are formed from the remains of ancient, microscopic algae (diatoms) and other once-living things. These remains were deposited in the mud on the bottom of the ocean or lake where the organisms lived. Under the heat (above 50 °C) and pressure of burial deep in the earth, the remains were transformed into materials such as bitumen, kerogen, or petroleum.
Natural deposits of bitumen include lakes such as the Pitch Lake in Trinidad and Tobago and Lake Bermudez in Venezuela. Natural seeps occur in the La Brea Tar Pits and in the Dead Sea.
Bitumen also occurs in unconsolidated sandstones known as “oil sands” in Alberta, Canada, and the similar “tar sands” in Utah, US. The Canadian province of Alberta has most of the world’s reserves, in three huge deposits covering 142,000 square kilometres (55,000 sq mi), an area larger than England or New York state. These bituminous sands contain 166 billion barrels (26.4×10^9 m3) of commercially established oil reserves, giving Canada the third largest oil reserves in the world. Although historically it was used without refining to pave roads, nearly all of the output is now used as raw material for oil refineries in Canada and the United States.
The world’s largest deposit of natural bitumen, known as the Athabasca oil sands, is located in the McMurray Formation of Northern Alberta. This formation is from the early Cretaceous, and is composed of numerous lenses of oil-bearing sand with up to 20% oil. Isotopic studies show the oil deposits to be about 110 million years old. Two smaller but still very large formations occur in the Peace River oil sands and the Cold Lake oil sands, to the west and southeast of the Athabasca oil sands, respectively. Of the Alberta deposits, only parts of the Athabasca oil sands are shallow enough to be suitable for surface mining. The other 80% has to be produced by oil wells using enhanced oil recovery techniques like steam-assisted gravity drainage.
Much smaller heavy oil or bitumen deposits also occur in the Uinta Basin in Utah, US. The Tar Sand Triangle deposit, for example, is roughly 6% bitumen.
Bitumen may occur in hydrothermal veins. An example of this is within the Uinta Basin of Utah, in the US, where there is a swarm of laterally and vertically extensive veins composed of a solid hydrocarbon termed Gilsonite. These veins formed by the polymerization and solidification of hydrocarbons that were mobilized from the deeper oil shales of the Green River Formation during burial and diagenesis.
Bitumen is similar to the organic matter in carbonaceous meteorites. However, detailed studies have shown these materials to be distinct. The vast Alberta bitumen resources are considered to have started out as living material from marine plants and animals, mainly algae, that died millions of years ago when an ancient ocean covered Alberta. They were covered by mud, buried deeply over time, and gently cooked into oil by geothermal heat at a temperature of 50 to 150 °C (120 to 300 °F). Due to pressure from the rising of the Rocky Mountains in southwestern Alberta, 80 to 55 million years ago, the oil was driven northeast hundreds of kilometres and trapped into underground sand deposits left behind by ancient river beds and ocean beaches, thus forming the oil sands.
The use of natural bitumen for waterproofing, and as an adhesive dates at least to the fifth millennium BC, with a crop storage basket discovered in Mehrgarh, of the Indus Valley Civilization, lined with it. By the 3rd millennia BC refined rock asphalt was in use, in the region, and was used to waterproof the Great Bath, Mohenjo-daro.
In the ancient Middle East, the Sumerians used natural bitumen deposits for mortar between bricks and stones, to cement parts of carvings, such as eyes, into place, for ship caulking, and for waterproofing. The Greek historian Herodotus said hot bitumen was used as mortar in the walls of Babylon.
The 1 kilometre (0.62 mi) long Euphrates Tunnel beneath the river Euphrates at Babylon in the time of Queen Semiramis (ca. 800 BC) was reportedly constructed of burnt bricks covered with bitumen as a waterproofing agent.
Bitumen was used by ancient Egyptians to embalm mummies. The Persian word for asphalt is moom, which is related to the English word mummy. The Egyptians’ primary source of bitumen was the Dead Sea, which the Romans knew as Palus Asphaltites (Asphalt Lake).
Approximately 40 AD, Dioscorides described the Dead Sea material as Judaicum bitumen, and noted other places in the region where it could be found. The Sidon bitumen is thought to refer to material found at Hasbeya. Pliny refers also to bitumen being found in Epirus. It was a valuable strategic resource, the object of the first known battle for a hydrocarbon deposit—between the Seleucids and the Nabateans in 312 BC.
In the ancient Far East, natural bitumen was slowly boiled to get rid of the higher fractions, leaving a thermoplastic material of higher molecular weight that when layered on objects became quite hard upon cooling. This was used to cover objects that needed waterproofing, such as scabbards and other items. Statuettes of household deities were also cast with this type of material in Japan, and probably also in China.
In North America, archaeological recovery has indicated bitumen was sometimes used to adhere stone projectile points to wooden shafts. In Canada, aboriginal people used bitumen seeping out of the banks of the Athabasca and other rivers to waterproof birch bark canoes, and also heated it in smudge pots to ward off mosquitoes in the summer.
In 1553, Pierre Belon described in his work Observations that pissasphalto, a mixture of pitch and bitumen, was used in the Republic of Ragusa (now Dubrovnik, Croatia) for tarring of ships.
An 1838 edition of Mechanics Magazine cites an early use of asphalt in France. A pamphlet dated 1621, by “a certain Monsieur d’Eyrinys, states that he had discovered the existence (of asphaltum) in large quantities in the vicinity of Neufchatel”, and that he proposed to use it in a variety of ways – “principally in the construction of air-proof granaries, and in protecting, by means of the arches, the water-courses in the city of Paris from the intrusion of dirt and filth”, which at that time made the water unusable. “He expatiates also on the excellence of this material for forming level and durable terraces” in palaces, “the notion of forming such terraces in the streets not one likely to cross the brain of a Parisian of that generation”.
But the substance was generally neglected in France until the revolution of 1830. In the 1830s there was a surge of interest, and asphalt became widely used “for pavements, flat roofs, and the lining of cisterns, and in England, some use of it had been made of it for similar purposes”. Its rise in Europe was “a sudden phenomenon”, after natural deposits were found “in France at Osbann (Bas-Rhin), the Parc (Ain) and the Puy-de-la-Poix (Puy-de-Dôme)”, although it could also be made artificially. One of the earliest uses in France was the laying of about 24,000 square yards of Seyssel asphalt at the Place de la Concorde in 1835.
Among the earlier uses of bitumen in the United Kingdom was for etching. William Salmon’s Polygraphice (1673) provides a recipe for varnish used in etching, consisting of three ounces of virgin wax, two ounces of mastic, and one ounce of asphaltum. By the fifth edition in 1685, he had included more asphaltum recipes from other sources.
The first British patent for the use of asphalt was “Cassell’s patent asphalte or bitumen” in 1834. Then on 25 November 1837, Richard Tappin Claridge patented the use of Seyssel asphalt (patent #7849), for use in asphalte pavement, having seen it employed in France and Belgium when visiting with Frederick Walter Simms, who worked with him on the introduction of asphalt to Britain. Dr T. Lamb Phipson writes that his father, Samuel Ryland Phipson, a friend of Claridge, was also “instrumental in introducing the asphalte pavement (in 1836)”. Indeed, mastic pavements had been previously employed at Vauxhall by a competitor of Claridge, but without success.
Claridge obtained a patent in Scotland on 27 March 1838, and obtained a patent in Ireland on 23 April 1838. In 1851, extensions for the 1837 patent and for both 1838 patents were sought by the trustees of a company previously formed by Claridge. Claridge’s Patent Asphalte Company—formed in 1838 for the purpose of introducing to Britain “Asphalte in its natural state from the mine at Pyrimont Seysell in France”,—”laid one of the first asphalt pavements in Whitehall”. Trials were made of the pavement in 1838 on the footway in Whitehall, the stable at Knightsbridge Barracks,”and subsequently on the space at the bottom of the steps leading from Waterloo Place to St. James Park”. “The formation in 1838 of Claridge’s Patent Asphalte Company (with a distinguished list of aristocratic patrons, and Marc and Isambard Brunel as, respectively, a trustee and consulting engineer), gave an enormous impetus to the development of a British asphalt industry”. “By the end of 1838, at least two other companies, Robinson’s and the Bastenne company, were in production”, with asphalt being laid as paving at Brighton, Herne Bay, Canterbury, Kensington, the Strand, and a large floor area in Bunhill-row, while meantime Claridge’s Whitehall paving “continue(d) in good order”.
Asphalt Maintenance in Northgate ?A high-speed toll booth on SR 417 near Orlando, Florida, United States. A toll collection area in the United Kingdom. Hong Kong toll booth.
A toll road, also known as a turnpike or tollway, is a public or private road for which a fee (or toll) is assessed for passage. It is a form of road pricing typically implemented to help recoup the cost of road construction and maintenance.
Toll roads have existed in some form since antiquity, with tolls levied on passing travellers on foot, wagon or horseback; but their prominence increased with the rise of the automobile, and many modern tollways charge fees for motor vehicles exclusively. The amount of the toll usually varies by vehicle type, weight, or number of axles, with freight trucks often charged higher rates than cars.
Tolls are often collected at toll booths, toll houses, plazas, stations, bars, or gates. Some toll collection points are unmanned and the user deposits money in a machine which opens the gate once the correct toll has been paid. To cut costs and minimise time delay many tolls today are collected by some form of automatic or electronic toll collection equipment which communicates electronically with a toll payer's transponder. Some electronic toll roads also maintain a system of toll booths so people without transponders can still pay the toll, but many newer roads now use automatic number plate recognition to charge drivers who use the road without a transponder, and some older toll roads are being upgraded with such systems.
Criticisms of toll roads include the time taken to stop and pay the toll, and the cost of the toll booth operators—up to about one third of revenue in some cases. Automated toll paying systems help minimise both of these. Others object to paying "twice" for the same road: in fuel taxes and with tolls.
In addition to toll roads, toll bridges and toll tunnels are also used by public authorities to generate funds to repay the cost of building the structures. Some tolls are set aside to pay for future maintenance or enhancement of infrastructure, or are applied as a general fund by local governments, not being earmarked for transport facilities. This is sometimes limited or prohibited by central government legislation. Also road congestion pricing schemes have been implemented in a limited number of urban areas as a transportation demand management tool to try to reduce traffic congestion and air pollution.A table of tolls in pre-decimal currency for the College Road, Dulwich, London SE21 tollgate.
Toll roads have existed for at least the last 2,700 years, as tolls had to be paid by travellers using the Susa–Babylon highway under the regime of Ashurbanipal, who reigned in the 7th century BC. Aristotle and Pliny refer to tolls in Arabia and other parts of Asia. In India, before the 4th century BC, the Arthashastra notes the use of tolls. Germanic tribes charged tolls to travellers across mountain passes.
A 14th-century example (though not for a road) is Castle Loevestein in the Netherlands, which was built at a strategic point where two rivers meet. River tolls were charged on boats sailing along the river. The Øresund in Scandinavia was once subject to a toll to the Danish Monarch, which once provided a sizable portion of the king's revenue.
Many modern European roads were originally constructed as toll roads in order to recoup the costs of construction, maintenance and as a source of tax money that is paid primarily by someone other than the local residents. In 14th-century England, some of the most heavily used roads were repaired with money raised from tolls by pavage grants. Widespread toll roads sometimes restricted traffic so much, by their high tolls, that they interfered with trade and cheap transportation needed to alleviate local famines or shortages.
Tolls were used in the Holy Roman Empire in the 14th and 15th centuries.
Industrialisation in Europe needed major improvements to the transport infrastructure which included many new or substantially improved roads, financed from tolls. The A5 road in Britain was built to provide a robust transport link between Britain and Ireland and had a toll house every few miles.
In the 20th century, road tolls were introduced in Europe to finance the construction of motorway networks and specific transport infrastructure such as bridges and tunnels. Italy was the first European country to charge motorway tolls, on a 50 km motorway section near Milan in 1924. It was followed by Greece, which made users pay for the network of motorways around and between its cities in 1927. Later in the 1950s and 1960s, France, Spain and Portugal started to build motorways largely with the aid of concessions, allowing rapid development of this infrastructure without massive State debts. Since then, road tolls have been introduced in the majority of the EU Member States.
In the United States, prior to the introduction of the Interstate Highway System and the large federal grants supplied to states to build it, many states constructed their first controlled-access highways by floating bonds backed by toll revenues. Starting with the Pennsylvania Turnpike in 1940, and followed by similar roads in New Jersey (Garden State Parkway (1946) and New Jersey Turnpike, 1952), New York (New York State Thruway, 1954), Massachusetts (Massachusetts Turnpike, 1957), and others, numerous states throughout the 1950s established major toll roads. With the establishment of the Interstate Highway System in the late 1950s, toll road construction in the U.S. slowed down considerably, as the federal government now provided the bulk of funding to construct new freeways, and regulations required that such Interstate highways be free from tolls. Many older toll roads were added to the Interstate System under a grandfather clause that allowed tolls to continue to be collected on toll roads that predated the system. Some of these such as the Connecticut Turnpike and the Richmond–Petersburg Turnpike later removed their tolls when the initial bonds were paid off. Many states, however, have maintained the tolling of these roads, however, as a consistent source of revenue.
As the Interstate Highway System approached completion during the 1980s, states began constructing toll roads again to provide new controlled-access highways which were not part of the original interstate system funding. Houston's outer beltway of interconnected toll roads began in 1983, and many states followed over the last two decades of the 20th century adding new toll roads, including the tollway system around Orlando, Florida, Colorado's E-470, and Georgia State Route 400.
London, in an effort to reduce traffic within the city, instituted the London congestion charge in 2003, effectively making all roads within the city tolled.
In the United States, as states looked for ways to construct new freeways without federal funding again, to raise revenue for continued road maintenance, and to control congestion, new toll road construction saw significant increases during the first two decades of the 21st century. Spurred on by two innovations, the electronic toll collection system, and the advent of high occupancy and express lane tolls, many areas of the U.S saw large road building projects in major urban areas. Electronic toll collection, first introduced in the 1980s, reduces operating costs by removing toll collectors from roads. Tolled express lanes, by which certain lanes of a freeway are designated "toll only", increases revenue by allowing a free-to-use highway collect revenue by allowing drivers to bypass traffic jams by paying a toll. The E-ZPass system, compatible with many state systems, is the largest ETC system in the U.S., and is used for both fully tolled highways and tolled express lanes. Maryland Route 200 and the Triangle Expressway in North Carolina were the first toll roads built without toll booths, with drivers charged via ETC or by optical license plate recognition and are billed by mail.19th-century toll booth in Brooklyn, New York Toll bar in Romania, 1877 Plaque commemorating the suppression of toll on a York bridge in 1914. Main article: Toll roads in Great Britain
Turnpike trusts were established in England and Wales from about 1706 in response to the need for better roads than the few and poorly-maintained tracks then available. Turnpike trusts were set up by individual Acts of Parliament, with powers to collect road tolls to repay loans for building, improving, and maintaining the principal roads in Britain. At their peak, in the 1830s, over 1,000 trusts administered around 30,000 miles (48,000 km) of turnpike road in England and Wales, taking tolls at almost 8,000 toll-gates. The trusts were ultimately responsible for the maintenance and improvement of most of the main roads in England and Wales, which were used to distribute agricultural and industrial goods economically. The tolls were a source of revenue for road building and maintenance, paid for by road users and not from general taxation. The turnpike trusts were gradually abolished from the 1870s. Most trusts improved existing roads, but some new roads, usually only short stretches, were also built. Thomas Telford's Holyhead road followed Watling Street from London but was exceptional in creating a largely new route beyond Shrewsbury, and especially beyond Llangollen. Built in the early 19th century, with many toll booths along its length, most of it is now the A5. In the modern day, one major toll road is the M6 Toll, relieving traffic congestion on the M6 in Birmingham. A few notable bridges and tunnels continue as toll roads including the Severn Bridge, the Dartford Crossing and Mersey Gateway bridge.
Some cities in Canada had toll roads in the 19th century. Roads radiating from Toronto required users to pay at toll gates along the street (Yonge Street, Bloor Street, Davenport Road, Kingston Road) and disappeared after 1895.
19th-century plank roads were usually operated as toll roads. One of the first U.S. motor roads, the Long Island Motor Parkway (which opened on October 10, 1908) was built by William Kissam Vanderbilt II, the great-grandson of Cornelius Vanderbilt. The road was closed in 1938 when it was taken over by the state of New York in lieu of back taxes.Main article: Road pricing
Road tolls were levied traditionally for a specific access (e.g. city) or for a specific infrastructure (e.g. roads, bridges). These concepts were widely used until the last century. However, the evolution in technology made it possible to implement road tolling policies based on different concepts. The different charging concepts are designed to suit different requirements regarding purpose of the charge, charging policy, the network to the charge, tariff class differentiation etc.:
Time Based Charges and Access Fees: In a time-based charging regime, a road user has to pay for a given period of time in which they may use the associated infrastructure. For the practically identical access fees, the user pays for the access to a restricted zone for a period or several days.
Motorway and other Infrastructure Tolling: The term tolling is used for charging a well-defined special and comparatively costly infrastructure, like a bridge, a tunnel, a mountain pass, a motorway concession or the whole motorway network of a country. Classically a toll is due when a vehicle passes a tolling station, be it a manual barrier-controlled toll plaza or a free-flow multi-lane station.
Distance or Area Charging: In a distance or area charging system concept, vehicles are charged per total distance driven in a defined area.
Some toll roads charge a toll in only one direction. Examples include the Sydney Harbour Bridge, Sydney Harbour Tunnel and Eastern Distributor (these all charge tolls city-bound) in Australia, the Severn Bridges where the M4 and M48 in Great Britain crosses the River Severn, in the United States, crossings between Pennsylvania and New Jersey operated by Delaware River Port Authority and crossings between New Jersey and New York operated by Port Authority of New York and New Jersey.This technique is practical where the detour to avoid the toll is large or the toll differences are small.
.Balintawak toll plaza of the North Luzon Expressway in Caloocan, Philippines. The toll barrier has both electronic toll collection and cash payment in the same barrier, before a new toll plaza was added. Tipo toll plaza in Subic–Clark–Tarlac Expressway, Hermosa, Bataan The open road tolling lanes at the West 163rd Street toll plaza, on the Tri-State Tollway near Markham, Illinois, United States
.Overhead cameras and reader attach to gantry on Highway 407 in Ontario. See also: Electronic toll collection
Traditionally tolls were paid by hand at a toll gate. Although payments may still be made in cash, it is more common now to pay by credit card, by pre-paid card, or by an electronic toll collection system. In some places, payment is made using stickers which are affixed to the windscreen.
Three systems of toll roads exist: open (with mainline barrier toll plazas); closed (with entry/exit tolls) and open road (no toll booths, only electronic toll collection gantries at entrances and exits, or at strategic locations on the mainline of the road). Modern toll roads often use a combination of the three, with various entry and exit tolls supplemented by occasional mainline tolls: for example the Pennsylvania Turnpike and the New York State Thruway implement both systems in different sections.
On an open toll system, all vehicles stop at various locations along the highway to pay a toll. (Not to be confused with "open road tolling", where no vehicles stop to pay toll.) While this may save money from the lack of need to construct toll booths at every exit, it can cause traffic congestion while traffic queues at the mainline toll plazas (toll barriers). It is also possible for motorists to enter an 'open toll road' after one toll barrier and exit before the next one, thus travelling on the toll road toll-free. Most open toll roads have ramp tolls or partial access junctions to prevent this practice, known in the U.S. as "shunpiking".
With a closed system, vehicles collect a ticket when entering the highway. In some cases, the ticket displays the toll to be paid on exit. Upon exit, the driver must pay the amount listed for the given exit. Should the ticket be lost, a driver must typically pay the maximum amount possible for travel on that highway. Short toll roads with no intermediate entries or exits may have only one toll plaza at one end, with motorists traveling in either direction paying a flat fee either when they enter or when they exit the toll road. In a variant of the closed toll system, mainline barriers are present at the two endpoints of the toll road, and each interchange has a ramp toll that is paid upon exit or entry. In this case, a motorist pays a flat fee at the ramp toll and another flat fee at the end of the toll road; no ticket is necessary. In addition, with most systems, motorists may pay tolls only with cash and/or change; debit and credit cards are not accepted. However, some toll roads may have travel plazas with ATMs so motorists can stop and withdraw cash for the tolls.
The toll is calculated by the distance travelled on the toll road or the specific exit chosen. In the United States, for instance, the Kansas Turnpike, Ohio Turnpike, Pennsylvania Turnpike, New Jersey Turnpike, most of the Indiana Toll Road, New York State Thruway, and Florida's Turnpike currently implement closed systems.
The Union Toll Plaza on the Garden State Parkway was the first ever to use an automated toll collection machine. A plaque commemorating the event includes the first quarter collected at its toll booths.
The first major deployment of an RFID electronic toll collection system in the United States was on the Dallas North Tollway in 1989 by Amtech (see TollTag). The Amtech RFID technology used on the Dallas North Tollway was originally developed at Sandia Labs for use in tagging and tracking livestock. In the same year, the Telepass active transponder RFID system was introduced across Italy.
Highway 407 in the province of Ontario, Canada, has no toll booths, and instead reads a transponder mounted on the windshields of each vehicle using the road (the rear licence plates of vehicles lacking a transponder are photographed when they enter and exit the highway). This made the highway the first all-automated toll highway in the world. A bill is mailed monthly for usage of the 407. Lower charges are levied on frequent 407 users who carry electronic transponders in their vehicles. The approach has not been without controversy: In 2003 the 407 ETR settled a class action with a refund to users.
Throughout most of the East Coast of the United States, E-ZPass (operated under the brand I-Pass in Illinois) is accepted on almost all toll roads. Similar systems include SunPass in Florida, FasTrak in California, Good to Go in Washington State, and ExpressToll in Colorado. The systems use a small radio transponder mounted in or on a customer's vehicle to deduct toll fares from a pre-paid account as the vehicle passes through the toll barrier. This reduces manpower at toll booths and increases traffic flow and fuel efficiency by reducing the need for complete stops to pay tolls at these locations.E-ZPass lanes at a New Jersey Turnpike (I-95) Toll Gate for Exit 8A in Monroe Township, New Jersey, United States
By designing a tollgate specifically for electronic collection, it is possible to carry out open-road tolling, where the customer does not need to slow at all when passing through the tollgate. The U.S. state of Texas is testing a system on a stretch of Texas 121 that has no toll booths. Drivers without a TollTag have their license plate photographed automatically and the registered owner will receive a monthly bill, at a higher rate than those vehicles with TollTags.
The first all-electric toll road in the eastern United States, the InterCounty Connector (Maryland Route 200) was partially opened to traffic in February 2011, and the final segment was completed in November 2014. The first section of another all-electronic toll road, the Triangle Expressway, opened at the beginning of 2012 in North Carolina.
Some toll roads are managed under such systems as the Build-Operate-Transfer (BOT) system. Private companies build the roads and are given a limited franchise. Ownership is transferred to the government when the franchise expires. This type of arrangement is prevalent in Australia, Canada, Hong Kong, India, South Korea, Japan and the Philippines. The BOT system is a fairly new concept that is gaining ground in the United States, with California, Delaware, Florida, Illinois, Indiana, Mississippi, Texas, and Virginia already building and operating toll roads under this scheme. Pennsylvania, Massachusetts, New Jersey, and Tennessee are also considering the BOT methodology for future highway projects.
The more traditional means of managing toll roads in the United States is through semi-autonomous public authorities. Kansas, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, and West Virginia manage their toll roads in this manner. While most of the toll roads in California, Delaware, Florida, Texas, and Virginia are operating under the BOT arrangement, a few of the older toll roads in these states are still operated by public authorities.
In France, all toll roads are operated by private companies, and the government takes a part of their profit.
Toll roads have been criticized as being inefficient in various ways:
- They require vehicles to stop or slow down (except open road tolling); manual toll collection wastes time and raises vehicle operating costs.
- Collection costs can absorb up to one-third of revenues, and revenue theft is considered to be comparatively easy.
- Where the tolled roads are less congested than the parallel "free" roads, the traffic diversion resulting from the tolls increases congestion on the road system and reduces its usefulness.
- By tracking the vehicle locations, their drivers are subject to an effectual restriction of their freedom of movement and freedom from excessive surveillance.
A number of additional criticisms are also directed at toll roads in general:
- Toll roads are a form of regressive taxation; that is, compared to conventional taxes for funding roads, they benefit wealthier citizens more than poor citizens.
- If toll roads are owned or managed by private entities, the citizens may lose money overall compared to conventional public funding because the private owners/operators of the toll system will naturally seek to profit from the roads.
- The managing entities, whether public or private, may not correctly account for the overall social costs, particularly to the poor, when setting pricing and thus may hurt the neediest segments of society.
SidewalkMacadam country road[dubious – discuss]
Macadam is a type of road construction, pioneered by Scottish engineer John Loudon McAdam around 1820, in which single-sized crushed stone layers of small angular stones are placed in shallow lifts and compacted thoroughly. A binding layer of stone dust (crushed stone from the original material) may form; it may also, after rolling, be covered with a binder to keep dust and stones together. The method simplified what had been considered state of the art at that point.
Pierre-Marie-Jérôme Trésaguet is sometimes considered the first person to bring post-Roman science to road building. A Frenchman from an engineering family, he worked paving roads in Paris from 1757 to 1764. As chief engineer of road construction of Limoges, he had opportunity to develop a better and cheaper method of road construction. In 1775, Tresaguet became engineer-general and presented his answer for road improvement in France, which soon became standard practice there.
Trésaguet had recommended a roadway consisting of three layers of stones laid on a crowned subgrade with side ditches for drainage. The first two layers consisted of angular hand-broken aggregate, maximum size 3 inches (7.6 cm), to a depth of about 8 inches (20 cm). The third layer was about 2 inches (5 cm) thick with a maximum aggregate size of 1 inch (2.5 cm). This top level surface permitted a smoother shape and protected the larger stones in the road structure from iron wheels and horse hooves. To keep the running surface level with the countryside, this road was put in a trench, which created drainage problems. These problems were addressed by changes that included digging deep side ditches, making the surface as solid as possible, and constructing the road with a difference in elevation (height) between the two edges, that difference being referred to interchangeably as the road's camber or cross slope.Laying Telford paving in Aspinwall, Pennsylvania, 1908
Thomas Telford, born in Dumfriesshire Scotland, was a surveyor and engineer who applied Tresaguet's road building theories. In 1801 Telford worked for the British Commission of Highlands Roads and Bridges. He became director of the Holyhead Road Commission between 1815 and 1830. Telford extended Tresaguet's theories, but emphasized high-quality stone. He recognized that some of the road problems of the French could be avoided by using cubical stone blocks.
Telford used roughly 12 in × 10 in × 6 in (30 cm × 25 cm × 15 cm) partially shaped paving stones (pitchers), with a slight flat face on the bottom surface. He turned the other faces more vertically than Tresaguet's method. The longest edge was arranged crossways to the traffic direction, and the joints were broken in the method of conventional brickwork, but with the smallest faces of the pitcher forming the upper and lower surfaces.
Broken stone was wedged into the spaces between the tapered perpendicular faces to provide the layer with good lateral control. Telford kept the natural formation level and used masons to camber the upper surface of the blocks. He placed a 6-inch (15 cm) layer of stone no bigger than 6 cm (2.4 in) on top of the rock foundation. To finish the road surface he covered the stones with a mixture of gravel and broken stone. This structure came to be known as "Telford pitching." Telford's road depended on a resistant structure to prevent water from collecting and corroding the strength of the pavement. Telford raised the pavement structure above ground level whenever possible.
Where the structure could not be raised, Telford drained the area surrounding the roadside. Previous road builders in Britain ignored drainage problems and Telford's rediscovery of these principles was a major contribution to road construction. Though notably of around the same time, John Metcalf was a strong advocate that drainage was in fact an important factor to road construction, and astonished colleagues by building dry roads through marshland. He accomplished this by installing a layer of brushwood and heather.John Loudon McAdam (1756–1836)
John Loudon McAdam was born in Ayr, Scotland, in 1756. In 1787, he became a trustee of the Ayrshire Turnpike in the Scottish Lowlands and during the next seven years this hobby became an obsession. He moved to Bristol, England, in 1802 and became a Commissioner for Paving in 1806. On 15 January 1816, he was elected Surveyor-General of roads for the Turnpike Trust and was now responsible for 149 miles of road. He then put his ideas about road construction into practice, the first 'macadamised' stretch of road being Marsh Road at Ashton Gate, Bristol. He also began to actively propagate his ideas in two booklets called Remarks (or Observations) on the Present System of Roadmaking, (which ran nine editions between 1816 and 1827) and A Practical Essay on the Scientific Repair and Preservation of Public Roads, published in 1819.Photograph of macadam road, ca 1850s, Nicolaus, California
McAdam's method was simpler, yet more effective at protecting roadways: he discovered that massive foundations of rock upon rock were unnecessary, and asserted that native soil alone would support the road and traffic upon it, as long as it was covered by a road crust that would protect the soil underneath from water and wear.
Unlike Telford and other road builders of the time, McAdam laid his roads as level as possible. His 30-foot-wide (9.1 m) road required only a rise of 3 inches (7.6 cm) from the edges to the centre. Cambering and elevation of the road above the water table enabled rain water to run off into ditches on either side.
Size of stones was central to the McAdam's road building theory. The lower 20-centimetre (7.9 in) road thickness was restricted to stones no larger than 7.5 centimetres (3.0 in). The upper 5-centimetre (2.0 in) layer of stones was limited to 2 centimetres (0.79 in) size and stones were checked by supervisors who carried scales. A workman could check the stone size himself by seeing if the stone would fit into his mouth. The importance of the 2 cm stone size was that the stones needed to be much smaller than the 10 cm width of the iron carriage tyres that travelled on the road.
McAdam believed that the "proper method" of breaking stones for utility and rapidity was accomplished by people sitting down and using small hammers, breaking the stones so that none of them was larger than six ounces in weight. He also wrote that the quality of the road would depend on how carefully the stones were spread on the surface over a sizeable space, one shovelful at a time.
McAdam directed that no substance that would absorb water and affect the road by frost should be incorporated into the road. Neither was anything to be laid on the clean stone to bind the road. The action of the road traffic would cause the broken stone to combine with its own angles, merging into a level, solid surface that would withstand weather or traffic.
Through his road-building experience, McAdam had learned that a layer of broken angular stones would act as a solid mass and would not require the large stone layer previously used to build roads. Keeping the surface stones smaller than the tyre width made a good running surface for traffic. The small surface stones also provided low stress on the road, so long as it could be kept reasonably dry.Construction of the first macadamized road in the United States (1823). In the foreground, workers are breaking stones "so as not to exceed 6 ounces [170 g] in weight or to pass a two-inch [5 cm] ring".
The first macadam road built in the United States was constructed between Hagerstown and Boonsboro, Maryland and was named at the time Boonsborough Turnpike Road. This was the last section of unimproved road between Baltimore on the Chesapeake Bay to Wheeling on the Ohio River. Stagecoaches traveling the Hagerstown to Boonsboro road in the winter took 5 to 7 hours to cover the 10-mile (16 km) stretch. This road was completed in 1823, using McAdam's road techniques, except that the finished road was compacted with a cast-iron roller instead of relying on road traffic for compaction. The second American road built using McAdam principles was the Cumberland Road which was 73 miles (117 km) long and was completed in 1830 after five years of work.
McAdam's renown is due to his effective and economical construction, which was a great improvement over the methods used by his generation. He emphasized that roads could be constructed for any kind of traffic, and he helped to alleviate the resentment travelers felt toward increasing traffic on the roads. His legacy lies in his advocacy of effective road maintenance and management. He advocated a central road authority and the trained professional official, who could be paid a salary that would keep him from corruption. This professional could give his entire time to his duties and be held responsible for his actions.
McAdam's road building technology was applied to roads by other engineers. One of these engineers was Richard Edgeworth, who filled the gaps between the surface stones with a mixture of stone dust and water, providing a smoother surface for the increased traffic using the roads. This basic method of construction is sometimes known as water-bound macadam. Although this method required a great deal of manual labour, it resulted in a strong and free-draining pavement. Roads constructed in this manner were described as "macadamized."New macadam road construction at McRoberts, Kentucky: pouring tar. 1926
With the advent of motor vehicles, dust became a serious problem on macadam roads. The area of low air pressure created under fast-moving vehicles sucked dust from the road surface, creating dust clouds and a gradual unraveling of the road material. This problem was approached by spraying tar on the surface to create tar-bound macadam. On March 13, 1902 in Monaco, a Swiss doctor, Ernest Guglielminetti, came upon the idea of using tar from Monaco's gasworks for binding the dust. Later a mixture of coal tar and ironworks slag, patented by Edgar Purnell Hooley as tarmac, was introduced.
A more durable road surface (modern mixed asphalt pavement) sometimes referred to in the US as blacktop, was introduced in the 1920s. This pavement method mixed the aggregates into the asphalt with the binding material before they were laid. The macadam surface method laid the stone and sand aggregates on the road and then sprayed it with the binding material. While macadam roads have now been resurfaced in most developed countries, some are preserved along stretches of roads such as the United States' National Road.
Because of the historic use of macadam as a road surface, roads in some parts of the United States (as parts of Pennsylvania) are often referred to as macadam, even though they might be made of asphalt or concrete. Similarly, the term "tarmac" is sometimes colloquially misapplied to asphalt roads or aircraft runways.