A road is an identifiable route, way or path between two or more places. A road number is often assigned to a stretch of public roadway A trail is a Path or Road used for Walking, Cycling, Cross-country skiing, or other activities In Geography, location is a position or point in Physical space that something occupies on Earths' surface ^[1] Roads are typically smoothed, paved, or otherwise prepared to allow easy travel;^[2] though they need not be, and historically many roads were simply recognizable routes without any formal construction or maintenance. Travel is the change in location of people on a trip through the means of Transport from one location to another In the fields of Architecture and Civil engineering, construction is a process that consists of the Building or assembling of Infrastructure Maintenance repair and operations or maintenance repair and overhaul (MRO is fixing any sort of mechanical or Electrical device should it ^[3]

The term was also commonly used to refer to natural waterways that leant themselves to use by shipping. Notable examples being Hampton Roads, in Virginia, and Castle Roads, in Bermuda (also formerly in Virginia). Hampton Roads is the name of both a body of water and the region of land areas which surround it in southeastern Virginia in the USA. The Commonwealth of Virginia ( is an American state ' Castle Roads' is the primary channel by which vessels enter Castle Harbour, Bermuda, from the Atlantic Ocean. Ba (officially The Bermuda Islands or The Somers Isles) is a British overseas territory in the North Atlantic Ocean.

In urban areas roads may pass through a city or village and be named as streets, serving a dual function as urban space easement and route. A city is an Urban area with a large Population and a particular Administrative, Legal, or Historical status A village is a clustered human settlement or community, larger than a hamlet, but smaller than a Town or City. A street is a Public thoroughfare in the built environment It is a Public parcel of land adjoining Buildings in an urban context For railroad track easement see Track transition curve. An easement is the right or freedom to do something or the right to prevent ^[4] Economics and society depend heavily on efficient roads. Economics is the social science that studies the production distribution, and consumption of goods and services. A society is a Population of Humans characterized by patterns of relationships between individuals that share a distinctive Culture and Institutions In the European Union (EU) 44 % of all goods are moved by trucks over roads and 85 % of all persons are transported by cars, buses or coaches on roads. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in This article is about the semi-truck For the North American use of the word see Pickup truck. The term person is used in Common sense to mean an individual Human being. ^[5]

The United States has the largest network of roadways of any single country in the world with 6,430,366 km (2005). The United States of America —commonly referred to as the India has the second largest road system in the world with 3,383,344 km (2002). India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country People's Republic of China is third with 1,870,661 km of roadway (2004). Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES ^[6] When looking only at expressways the National Trunk Highway System (NTHS) in People's Republic of China has a total length of 45,000 km at the end of 2006, second only to the United States with 90,000 km in 2005. An expressway is a Divided highway for high-speed traffic with at least partial Control of access. This article is about the expressways of Mainland China. See also List of roads and streets in Hong Kong, List of roads in Macau, Highway System Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES ^[7][8]

Contents 1 Usage and etymology 2 History 2.1 Historical road construction dating to 4000 BC 3 Road transport economics 4 Environmental aspects 5 Driving on the right or the left 6 Construction 6.1 Duplication 7 Maintenance 8 Terminology 9 See also 10 References 11 External links

Usage and etymology

See also: Usage of the terms railroad and railway and Street name

In original usage, a "road" was simply any pathway fit for riding. A trail is a Path or Road used for Walking, Cycling, Cross-country skiing, or other activities For the Roman class see Equestrian (Roman Equestrianism refers to the skill of riding or driving Horses This broad description The word “street,” whose origin is the Latin strata, was kept for paved pathways that had been prepared to ease travel in some way. A street is a Public thoroughfare in the built environment It is a Public parcel of land adjoining Buildings in an urban context Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Thus, many "Roman Roads" have the word "street" as part of their name. ^[9][10] Roads are a prerequisite for road transport of goods on wheeled vehicles^[9]. Road transport ( British English) or road transportation ( American English) is Transport on Roads of passengers or goods A wheel is a circular device that is capable of rotating on its axis facilitating movement or transportation whilst supporting a load ( Mass) or performing labour in machines Vehicles, derived from the Latin word vehiculum, are non-living Means of transport.

Words with related usage include, Avenue, Boulevard, Court, Drive, Freeway, Highway, Lane, Parkway, Path, Street, Turnpike, and Way. British Archaeologists refine the general archaeological use of avenue to denote a long parallel-sided strip of land measuring up to about 30m in width open at either end and Boulevard ( French, from Bolwerk &ndash bolwark meaning bastion has several generally accepted meanings "Dead End Street" redirects here For the song by The Kinks see Dead End Street (song. * * * * * * * * * * * * * * * * * * * * * * Before adding any more images to this * * page please do carefully consider * * whether they would be mere decoration * * or actually improve The word lane has several meanings including and especially a portion of a paved Road which is intended for a single line of vehicles and is marked by White In the United States, Parkways are defined as follows A type of road A broad landscaped thoroughfare especially: one from which trucks and A trail is a Path or Road used for Walking, Cycling, Cross-country skiing, or other activities A street is a Public thoroughfare in the built environment It is a Public parcel of land adjoining Buildings in an urban context A toll road, (also known as a tollway, turnpike, pike, or toll highway, especially if it is constructed to Freeway standards

History

See also: History of road transport

That the first pathways were the trails made by animals has not been universally accepted, arguing that animals do not follow constant paths. A trail is a Path or Road used for Walking, Cycling, Cross-country skiing, or other activities ^[3] Others believe that some roads originated from humans following animal's trails. ^[11][12] The Icknield Way is given as an example of this type road origination were man and animal both selected the same natural line. This page refers to the old footpath Icknield Way. The modern footpath which partially follows the old route is called Icknield Way Path The ^[13] By about 10,000 BC, rough pathways were used by human travelers. ^[3]

Historical road construction dating to 4000 BC

• Stone paved streets are found in the city of Ur in the Middle East dating back to 4000 BC^[3]

• Corduroy road (log road) are found dating to 4,000 BC in Glastonbury, England^[3]

• The timber trackway; Sweet Track causeway in England, is one of the oldest engineered roads discovered and the oldest timber trackway discovered in Northern Europe. Cobblestones are stones that were frequently used in the pavement of early Streets "Cobblestone" is derived from the very old English word "cob" Ur ( Sumerian:urim; Akkadian: ?) is modern Tell el-Mukayyar, Iraq, and was a city in ancient Sumer. The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. A Corduroy road or log road is a type of Road made by placing Sand -covered Logs Perpendicular to the direction of the road over a low Glastonbury is a small town in Somerset, England, situated at a Dry point on the Somerset Levels, south of Bristol. The Sweet Track is an ancient Causeway in the Somerset Levels, England. In modern usage a causeway is a road or railway elevated by a bank usually across a broad Body of water or Wetland. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Northern Europe is a term for the northern part of Europe. The United Nations defines Northern Europe as (Finland Built in winter 3807 BC or spring 3806 BC, tree-ring dating (Dendrochronology) enabled very precise dating. Dendrochronology (from Greek grc δένδρον dendron, "tree" grc χρόνος khronos, "time" and grc -λογία It has been claimed to be the oldest road in the world. ^[14][9]

• Brick paved streets were used in India as early as 3000 BC^[3]

• In 500 BC, Darius I the Great started an extensive road system for Persia (Iran), including the famous Royal Road which was one of the finest highways of its time. A brick is a block of Ceramic material used in Masonry construction laid using mortar. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Darius I the Great (c 549 BC&ndash486 BC 𐎭𐎠𐎼𐎹𐎺𐎢𐏁 Dārayavahuš: "Possessing goodness" Having ascended to power amidst controversy and bloodshed The Persian Empire was a series of Iranian empires that ruled over the Iranian plateau, the original Persian homeland and beyond in Western Asia For a topic outline on this subject see List of basic Iran topics. The Persian Royal Road was an ancient highway reorganized and rebuilt by the Persian king Darius I of Achaemenid Empire in the 5th Century BC ^[15] The road remained in use after Roman times.

• In ancient times, transport by river was far easier and faster than transport by road,^[9] especially considering the cost of road construction and the difference in carrying capacity between carts and river barges. "Riverine" redirects here For the use of that term in Maritime geography, see there "CARTS" redirects here For the transportation system see Capital Area Rural Transportation System, or Chautauqua CARTS. BARGE, the Big August RecGambling Excursion is a yearly convention held in Las Vegas during the first weekend of August A hybrid of road transport and ship transport beginning in about 1740 is the horse-drawn boat in which the horse follows a cleared path along the river bank. Not to be confused with the modern Towboat. A horse-drawn boat or tow-boat is a historic Boat operating on a Canal ^[16][17]

• From about 312 BC, the Roman Empire built straight^[18] strong stone Roman roads throughout Europe and North Africa, in support of its military campaigns. The Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial The Roman Roads were essential for the growth of the Roman Empire, by enabling the Romans to move armies and trade goods and to communicate news North Africa or Northern Africa is the Northernmost Region of the African Continent, separated by the Sahara from Sub-Saharan At its peak the Roman Empire was connected by 29 major roads moving out from Rome and covering 78,000 kilometers or 52,964 Roman miles of paved roads. Rome ( Roma ˈroma Roma is the capital city of Italy and Lazio, and is Italy's largest and most populous city with more than 2 The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand A mile is a unit of Length, usually used to measure Distance, in a number of different systems including Imperial units United States ^[9]

• In the 1600's road construction and maintenance in Britain was traditionally done on a local parish basis. ^[9] This resulted in a poor and variable state of roads. To remedy this, the first of the 'Turnpike Trusts' around 1706, to build good roads and collect tolls from passing vehicles. Eventually there were approximately 1,100 Trusts in Britain and some 36,800 km of engineered roads. ^[9] The Rebecca Riots in Carmarthenshire and Rhayader from 1839 to 1844 contributed to having a Royal Commission and the demise of the system in 1844. The Rebecca Riots took place between 1839 and 1844 in South Wales and Mid Wales. Geography The county is bounded to the north by Ceredigion, to the east by Powys, Neath Port Talbot and Swansea, to the south by the Rhayader (Rhaeadr Gwy meaning Wye Falls is a historic Market town in Powys, Wales. ^[19]

Road transport economics

Main article: Transport economics

Transport economics is a branch of economics that deals with the allocation of resources within the transport sector and has strong linkages with civil engineering. Transport economics is a branch of Economics that deals with the allocation of resources within the transport sector and has strong linkages with Civil engineering Economics is the social science that studies the production distribution, and consumption of goods and services. Civil engineering is a professional engineering discipline that deals with the design construction and maintenance of the physical and naturally built Transport economics differs from some other branches of economics in that the assumption of a spaceless, instantaneous economy does not hold. Transport or transportation is the movement of people and goods from one place to another An economy is the realized social system of production exchange distribution and consumption of goods and services of a country or other area People and goods flow over networks at certain speeds. Demands peak. Advanced ticket purchase is often induced by lower fares. The networks themselves may or may not be competitive. Competitiveness is a comparative concept of the ability and performance of a firm sub-sector or country to sell and supply goods and/or services in a given Market A single trip (the final good from the point-of-view of the consumer) may require bundling the services provided by several firms, agencies and modes.

Although transport systems follow the same supply and demand theory as other industries, the complications of network effects and choices between non-similar goods (e. Supply and demand is an Economic model describing effects on price and quantity in a Market. In Economics and Business, a network effect (also called network externality) is the effect that one user of a good or service has g. car and bus travel) make estimating the demand for transportation facilities difficult. The development of models to estimate the likely choices between the non-similar goods involved in transport decisions "discrete choice" models led to the development of the important branch of econometrics, and a Nobel Prize for Daniel McFadden. In economics "discrete choice" problems involve choices between two or more discrete alternatives such as entering or not entering the Labor market, or choosing between modes Econometrics is concerned with the tasks of developing and applying Quantitative or Statistical methods to the study and elucidation of economic principles The Nobel Prize (Nobelpriset (Nobelprisen is a Swedish prize established in the 1895 will of Swedish chemist Alfred Nobel; it was first awarded in Peace, Literature Daniel Little McFadden (born July 29, 1937) is an econometrician who won (jointly with James Heckman) the 2000 Nobel Memorial Prize ^[20]

In transport, demand can be measured in numbers of journeys made or in total distance traveled across all journeys (e. Supply and demand is an Economic model describing effects on price and quantity in a Market. g. passenger-kilometres for public transport or vehicle-kilometres of travel (VKT) for private transport). Private Transport is the first album by The Guild League released in 2002 on Candle Records (catalogue number TGL02 Supply is considered to be a measure of capacity. The price of the good (travel) is measured using the generalised cost of travel, which includes both money and time expenditure. Price in Economics and Business is the result of an exchange and from that trade we assign a numerical Monetary value to a good, In Transport economics, the generalised cost is the sum of the Monetary and non-monetary costs of a journey Money is anything that is generally accepted as Payment for Goods and services and repayment of Debts. For other uses see Time (disambiguation Time is a component of a measuring system used to sequence events to compare the durations of The effect of increases in supply (capacity) are of particular interest in transport economics (see induced demand), as the potential environmental consequences are significant. Induced demand is the phenomenon that after supply increases more of a good is consumed

Road building and maintenance is an area of economic activity that remains dominated by the public sector (though often through private contractors). The public sector is the part of economic and administrative life that deals with the delivery of goods and services by and for the Government, whether national Regional In Economics, the private sector is that part of the economy which is both run for private Profit and is not controlled by the State. A general contractor is a group or individual that Contracts with another organization or individual (the owner for the Construction or Renovation ^[21] Roads (except those on private property not accessible to the general public) are typically paid for by taxes (often raised through levies on fuel),^[22] though some public roads, especially highways are funded by tolls. A public road or Highway is a Road that is open to common use by the general population * * * * * * * * * * * * * * * * * * * * * * Before adding any more images to this * * page please do carefully consider * * whether they would be mere decoration * * or actually improve A toll road, (also known as a tollway, turnpike, pike, or toll highway, especially if it is constructed to Freeway standards ^[23]

Environmental aspects

Motor vehicle traffic on roads generate noise pollution especially at higher operating speeds. Noise pollution (or environmental noise) is displeasing human- or machine-created sound that disrupts the activity or balance of human or animal life Therefore, considerable noise health effects are expected from road systems used by large numbers of motor vehicles. Noise health effects are the Health consequences of elevated Sound levels Elevated workplace or other Noise can cause Hearing impairment Noise mitigation strategies exist to reduce sound levels at nearby sensitive receptors. Noise mitigation is a set of strategies to reduce Noise pollution. The idea that road design could be influenced by acoustical engineering considerations first arose about 1973. ^[24]

Motor vehicles operating on roads contribute emissions, particularly for congested city street conditions and other low speed circumstances. Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort Concentrations of air pollutants and adverse respiratory health effects are greater near the road than at some distance away from the road. ^[25]

Driving on the right or the left

Main article: Driving on the left or right

Traffic flows on the right or on the left side of the road depending on the country. Traffic on Roads may consist of Pedestrians ridden or herded Animals Vehicles Streetcars and other Conveyances either singly ^[26] In countries where traffic flows on the right, traffic signs are mostly on the right side of the road, roundabouts and traffic circles go counter-clockwise, and pedestrians crossing a two-way road should watch out for traffic from the left first. Most countries post signage known as traffic signs or road signs, at the side of Roads to A roundabout is a type of Road junction at which Traffic enters a one-way stream around a central island A traffic circle is an intersection with a circular shape and usually a central island A pedestrian is a person travelling on foot whether Walking or Running. ^[27] In countries where traffic flows on the left, the reverse is true.

About 34% of the world by population drive on the left, and 66% keep right. In Biology a population is the collection of inter-breeding organisms of a particular Species; in Sociology By roadway distances, about 28% drive on the left, and 72% on the right,^[28] even though originally most traffic drove on the left worldwide. ^[29]

Construction

Road construction requires the creation of a continuous right-of-way, overcoming geographic obstacles and having grades low enough to permit vehicle or foot travel. A right-of-way is a strip of land that is granted – through an Easement or other mechanism – for Transportation purposes such as for a Rail line or The grade (or gradient or pitch or slope) of any physical feature such as a Hill, Stream, Roof, railroad, or Vehicles, derived from the Latin word vehiculum, are non-living Means of transport. Walking (also called ambulation) is the main form of Animal Locomotion on land, distinguished from Running and crawling ^{[30] (pg15)} and may be required to meet standards set by law^[31] or official guidelines. Law is a system of rules enforced through a set of Institutions used as an instrument to underpin civil obedience politics economics and society ^[32] The process is often begun with the removal of earth and rock by digging or blasting, construction of embankments, bridges and tunnels, and removal of vegetation (this may involve deforestation) and followed by the laying of pavement material. To keep a Road or rail line straight and/or flat and where the comparative cost or practicality of alternate solutions (such as diversion is too prohibitive the land over A bridge is a Structure built to span a Gorge, Valley, Road, railroad track, River, Body of water A tunnel is an underground passageway The definition of what constitutes a tunnel is not universally agreed upon Deforestation is the conversion of Forested areas to non-forest land for use such as Arable land, Pasture, urban use logged area or wasteland A variety of road building equipment is employed in road building. Engineering vehicles, known by the other terms construction Equipment, earth movers heavy equipment or just plain equipment are machines specifically designed to execute ^{[33] [34]}

After design, approval, planning, legal and environmental considerations have been addressed alignment of the road is set out by a surveyor. Design is used both as a Noun and a Verb. The term is often tied to the various Applied arts and Engineering (See design disciplines In the United States, presidential job approval ratings were introduced by George Gallup in the late 1930s (probably 1937 to gauge public support for the president Planning in Organizations and Public policy is both the organizational process of creating and maintaining a Plan; and the psychological process of Law is a system of rules enforced through a set of Institutions used as an instrument to underpin civil obedience politics economics and society Environmental policy is any (course of action deliberately taken (or not taken to manage human activities with a view to prevent reduce or mitigate harmful effects on nature and natural Surveying is the technique and science of accurately determining the terrestrial or three-dimensional space Position of points and the distances and angles between ^[18] The Radii and gradient are designed and staked out to best suit the natural ground levels and minimize the amount of cut and fill. Slope is used to describe the steepness incline gradient or grade of a straight line. ^{[32] (page34)} Great care is taken to preserve reference Benchmarks ^{[32] (page59)}

Roadways are designed and built for primary use by vehicular and pedestrian traffic. This article is about the use of bench marks in surveying for other uses see Bench mark. Vehicles, derived from the Latin word vehiculum, are non-living Means of transport. A pedestrian is a person travelling on foot whether Walking or Running. Traffic on Roads may consist of Pedestrians ridden or herded Animals Vehicles Streetcars and other Conveyances either singly Storm drainage and environmental considerations are a major concern. A storm drain, storm sewer ( US) stormwater drain ( Australia and New Zealand) or surface water system ( UK) Erosion and sediment controls are constructed to prevent detrimental effects. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Drainage lines are laid with sealed joints in the road easement with runoff coefficients and characteristics adequate for the land zoning and storm water system. A mechanical seal is a device which helps join systems or mechanisms together by preventing leakage (e For railroad track easement see Track transition curve. An easement is the right or freedom to do something or the right to prevent In Mathematics, a coefficient is a Constant multiplicative factor of a certain object Zoning is a term used in Urban planning for a system of land-use Regulation in various parts of the world including North America the United Kingdom Drainage systems must be capable of carrying the ultimate design flow from the upstream catchment with approval for the outfall from the appropriate authority to a watercourse, creek, river or the sea for drainage discharge. A watercourse is any flowing body of Water. These include Rivers Streams Brooks Anabranches et cetera A stream is a body of Water with a current, confined within a bed and stream-banks "Riverine" redirects here For the use of that term in Maritime geography, see there This article is about the body of water For other uses see SEA and Seas. ^{[32] (page38 to 40)}

A Borrow pit (source for obtaining fill, gravel, and rock) and a water source should be located near or in reasonable distance to the road construction site. A borrow pit, also known as a sand box is a term used in Construction and Civil engineering. Approval from local authorities may be required to draw water or for working (crushing and screening) of materials for construction needs. Local governments are administrative offices that are smaller than a State. Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm The top soil and vegetation is removed from the borrow pit and stockpiled for subsequent rehabilitation of the extraction area. Topsoil is the upper outermost layer of soil usually the top 2 to 8 inches Vegetation is a general term for the plant life of a region it refers to the Ground cover provided by plants Side slopes in the excavation area not steeper than one vertical to two horizontal for safety reasons. ^{[32] (page 53 to 56 )}

Old road surfaces, fences, and buildings may need to be removed before construction can begin. Trees in the road construction area may be marked for retention. A tree is a perennial Woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or These protected trees should not have the topsoil within the area of the tree's drip line removed and the area should be kept clear of construction material and equipment. Compensation or replacement may be required if a protected tree is damaged. Much of the vegetation maybe mulched and put aside for use during reinstatement. In Agriculture and Gardening, '''mulch''' is a protective cover placed over the Soil, primarily to modify the effects of the local Climate. The topsoil is usually stripped and stockpiled nearby for rehabilitation of newly constructed embankments along the road. Topsoil is the upper outermost layer of soil usually the top 2 to 8 inches Stumps and roots are removed and holes filled as required before the earthwork begins. Final rehabilitation after road construction is completed will include seeding, planting, watering and other activities to reinstate the area to be consistent with the untouched surrounding areas. ^{[32] (page 66 to 67 )}

Processes during earthwork include excavation, removal of material to spoil, filling, compacting, construction and trimming. If rock or other unsuitable material is discovered it is removed, moisture content is managed and replaced with standard fill compacted to 90% relative compaction. Generally blasting of rock is discouraged in the road bed. Rock blasting is the controlled use of Explosives to excavate or remove rock. When a depression must be filled to come up to the road grade the native bed is compacted after the topsoil has been removed. The fill is made by the "compacted layer method" where a layer of fill is spread then compacted to specifications, the process is repeated until the desired grade is reached. ^{[32] (page 68 to 69 )}

General fill material should be free of organics, meet minimum California bearing ratio (CBR) results and have a low plasticity index. Fill dirt is earthy material which is used to fill in a depression or hole in the ground An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. The California bearing ratio ( CBR) is a penetration test for evaluation of the Mechanical strength of Road Subgrades and basecourses The Atterberg limits are a basic measure of the nature of a fine-grained Soil. Select fill (sieved) should be composed of gravel, decomposed rock or broken rock below a specified Particle size and be free of large lumps of clay. Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Crushed stone or angular rock is a form of Construction aggregate, typically produced by mining a suitable rock deposit and breaking the removed rock down to the desired Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and Sand clay fill may also be used. Loam is Soil composed of Sand, Silt, and Clay in relatively even concentration (about 40-40-20% concentration respectively considered The road bed must be "proof rolled" after each layer of fill is compacted. If a roller passes over an area without creating visible deformation or spring the section is deemed to comply. A road roller (sometimes called a roller-compactor, or just roller) is a Compactor type Engineering vehicle used to compact soil ^{[32] (page 70 to 72 )}

The completed road way is finished by paving or left with a gravel or other natural surface. Dirt road is a common term for Unpaved roads made from the native material of the land surface through which they pass known to highway engineers as Subgrade The type of road surface is dependent on economic factors and expected usage. Various types of road are in use around the world Roads range in size from private Driveways to the stereotypical two-lane Highway, to high capacity Safety improvements like Traffic signs, Crash barriers, Raised pavement markers, and other forms of Road surface marking are installed. Most countries post signage known as traffic signs or road signs, at the side of Roads to A crash barrier is a barrier on a road designed to prevent vehicles from leaving the roadway to improve Road safety. A raised pavement marker is a safety device used on Roads. These devices are usually made with plastic ceramic or occasionally metal and come in a variety Road surface marking is any kind of device or material that is used on a road surface in order to convey official information

Duplication

When a single carriageway road is converted into dual carriageway by building a second separate carriageway alongside the first, it is usually referred to as duplication^[35] or twinning. Single carriageway is the British designation for the most common type of Road; one with no physical separation ( Central reservation) between A dual carriageway or divided highway is a road or Highway in which the two directions of traffic are separated by a central barrier or strip of land known as a The original carriageway is changed from two-way to become one-way, while the new carriageway is one-way in the opposite direction. In the same way as converting railway lines from single track to double track, the new carriageway is not always constructed directly alongside the existing carriageway. A single track Railway is one where traffic in both directions shares the same track A double track railway usually involves running one track in each direction compared to a single track railway where trains in both directions share the same track

Maintenance

Like all structures, roads deteriorate over time. Deterioration is primarily due to accumulated damage from vehicles, however environmental effects such as frost heaves, thermal cracking and oxidation often contribute. Frost heaving (or frost heave) occurs when Soil expands and contracts due to freezing and thawing ^[36] According to a series of experiments carried out in the late 1950s, called the AASHO Road Test, it was empirically determined that the effective damage done to the road is roughly proportional to the 4th power of axle weight . The 1950s Decade refers to the years of 1950 to 1959 inclusive The AASHO Road Test was a series of experiments carried out by the American Association of State Highway and Transportation Officials to determine how traffic contributed to Gross axle weight rating ( GAWR) is the maximum distributed weight that may be supported by an Axle of a road vehicle ^[37] A typical tractor-trailer weighing 80,000 pounds (36. truckcartransporterarp750pixjpg|thumb|right|A tractor with an auto-transport Semi-trailer. The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass 287 t) with 8,000 pounds (3. This article is about the tonne or metric ton For other tons see Ton. 6287 t) on the steer axle and 36,000 pounds (16. 329 t) on both of the tandem axle groups is expected to do 7,800 times more damage than a passenger vehicle with 2,000 pounds (0. 907 t) on each axle.

pothole

Pavements are designed for an expected service life or design life. Potholing can also be the sport of exploring vertical caves as a synonym of Caving. A product's service life is its expected lifetime or the acceptable period of use in service The design life of a component or product is the period of time during which the item is expected by its designers to work within its specified parameters in other words the life expectancy In some UK countries the standard design life is 40 years for new bitumen and concrete pavement. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Bitumen is a mixture of organic Liquids that are highly Viscous, black sticky entirely soluble in Carbon disulfide, and composed primarily Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag Maintenance is considered in the whole life cost of the road with service at 10, 20 and 30 year milestones. ^[38] Roads can be and are designed for a variety of lives (8-, 15-, 30-, and 60-year designs). When pavement lasts longer then its intended life, it may have been overbuilt, and the original costs may have been too high. When a pavement fails before its intended design life, the owner may have excessive repair and rehabilitation costs. Many concrete pavements built since the 1950's have significantly outlived their intended design lives. ^[39] Some roads like Chicago, Illinois's "Wacker Drive", a major two-level viaduct in downtown area are being rebuilt with a designed service life of 100 years. Chicago (ʃɪˈkɑːgoʊ is the largest City by population in the state of Illinois and the American Midwest of the United States. Wacker Drive is a major street in Chicago, Illinois, United States, running along the south side of the main branch and the east side of the south ^[40]

Virtually all roads require some form of maintenance before they come to the end of their service life. Pro-active agencies continually monitor road conditions and apply preventive maintenance treatments as needed to prolong the lifespan of their roads. Technically advanced agencies monitior the road network surface condition with sophisticated equipment such as laser/inertial Profilometers. Profilometer is a Measuring instrument used to measure a surface's profile in order to Quantify its Roughness. These measurements include road curvature, cross slope, unevenness, roughness, rutting and texture (roads). In Mathematics, curvature refers to any of a number of loosely related concepts in different areas of geometry Cross slope is a geometric feature of pavement surfaces the transversal slope with respect to the horizon Roughness is a measure of the texture of a Surface. It is quantified by the vertical deviations of a real surface from its ideal form This data is fed into a pavement management system, which recommends the best maintenance or construction treatment to correct the damage that has occurred. Pavement management system or PMS is a term that relates to a system that utilizes the condition coding of roadways coupled with the identification of strategies to determine maintenance

Maintenance treatments for asphalt concrete generally include crack sealing, surface rejuvenating, fog sealing, micro-milling and surface treatments. Asphalt concrete, normally known simply as Asphalt, is a Composite material commonly used for construction of pavement, Highways and Chip Seal is a pavement surface treatment that combines a layer of Asphalt with a layer of fine aggregate. Thin surfacing preserves, protects and improves the functional condition of the road while reducing the need for routing maintenance, leading to extended service life without increasing structural capacity. ^[41]

Terminology

• Alignment (road) - Cross slope/Banking/Superelevation, horizontal and vertical curvature of a road. The A22 is one of the two-digit major Roads in the south east of England. East Sussex is a county in South East England. It is bordered by the counties of Kent, Surrey and West Sussex, and to the England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland
• All-weather road - Unpaved road that is constructed of a material that does not create mud during rainfall.
• Bollard - Rigid posts that can be arranged in a line to close a road or path to vehicles above a certain width
• Byway - Highway over which the public have a right to travel for vehicular and other kinds of traffic, but which is used mainly as footpaths and bridleways
• Bypass Road that avoids or "bypasses" a built-up area, town, or village
• Bottleneck - Section of a road with a carrying capacity substantially below that of other sections of the same road
• Botts' dots - Non reflective raised pavement marker used on roads
• Cat's eye - reflective raised pavement marker used on roads
• Chicane - Sequence of tight serpentine curves (usually an S-shape curve or a bus stop) in a roadway
• Chipseal - Road surface composed of a thin layer of crushed stone 'chips' and asphalt emulsion. A bollard is a short vertical post typically found where large Ships dock See also the disambiguation page Byway A byway in the United Kingdom is a minor secondary or tertiary road In England and Wales, public rights of way are paths on which the public have a legally protected right to pass and re-pass A bypass is a Road or Highway that avoids or "bypasses" a built-up area town or village to let through Traffic flow without interference from Metaphorically a bottleneck is a section of a route with a carrying capacity substantially below that characterising other sections of the same route Botts' dots are round nonreflective Raised pavement markers In many U A raised pavement marker is a safety device used on Roads. These devices are usually made with plastic ceramic or occasionally metal and come in a variety Reflection is the change in direction of a Wave front at an interface between two different media so that the wave front returns into the medium from which A raised pavement marker is a safety device used on Roads. These devices are usually made with plastic ceramic or occasionally metal and come in a variety A chicane is a sequence of tight serpentine curves (usually an S-shape curve or a bus stop in a roadway used in Motor racing and Chip Seal is a pavement surface treatment that combines a layer of Asphalt with a layer of fine aggregate. It seals the surface and protects it from weather, but provides no structural strength. It is cheaper than asphalt concrete or a concrete, in the U.S. it is usually only used on low volume rural roads
• Corniche - Road on the side of a cliff or mountain, with the ground rising on one side and falling away on the other
• Curb - Edge where a raised pavement/sidewalk/footpath, road median, or road shoulder meets an unraised street or other roadway. Asphalt concrete, normally known simply as Asphalt, is a Composite material commonly used for construction of pavement, Highways and Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag The United States of America —commonly referred to as the The word corniche comes from the French route à corniche or road on a ledge — do not confuse with Cornice, which In Geography and Geology, a cliff is a significant vertical or near vertical rock exposure A mountain is a Landform that extends above the surrounding Terrain in a limited area with a peak A curb or kerb (see spelling differences) is the edge where a raised pavement/sidewalk/footpath, Road median, or Road shoulder A sidewalk (chiefly North American English) pavement ( British English and Philadelphia dialect) footpath ( Australian English On divided roads including Expressways Motorways or Autobahns the central reservation (British English, median (North American A hard shoulder, or simply shoulder, is a reserved area by the verge of a Road or Motorway. A street is a Public thoroughfare in the built environment It is a Public parcel of land adjoining Buildings in an urban context
• Curb extension - (or also kerb extension, bulb-out, nib, elephant ear, curb bulge and blister) Traffic calming measure, intended to slow the speed of traffic and increase driver awareness, particularly in built-up and residential neighborhoods. A curb extension (or also kerb extension, bulb-out, kerb build-out, nib, elephant ear, curb bulge and blister Traffic calming is a set of strategies used by Urban planners and traffic engineers which aim to slow down or reduce Traffic, thereby improving safety A neighbourhood or neighborhood (see spelling differences) is a geographically localised Community within a larger City, Town or
• Fork - (literally "fork in the road") Type of intersection where a road splits
• Guard rail - Prevents vehicles from veering off the road into oncoming traffic, crashing against solid objects or falling from a road
• Green lane - (UK) Unsurfaced road, may be so infrequently used that vegetation colonises freely, hence 'green'. In the field of Road transport, an intersection is a road junction where two or more Roads either meet or cross at grade (they are Guard rail, sometimes referred to as guide rail, is a system designed to keep people or vehicles from (in most cases unintentionally straying into dangerous or off-limits areas A green lane is a type of Road. England and Wales See also Byway (road In particular a green lane is unsurfaced and may be so The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Many green lanes are ancient routes that have existed for millennia, similar to a Byway
• Interstate Highway System - United States System of Interstate and Defense Highways
• Median - On divided roads, including expressways, motorways, or autobahns, the central reservation (British English), median (North American English), median strip (North American English and Australian English), neutral ground [Louisiana English] or central nature strip (Australian English) is the area which separates opposing lanes of traffic
• Mountain pass - Lower point that allows easier access through a range of mountains
• Milestone - One of a series of numbered markers placed along a road at regular intervals, showing the distance to destinations. See also the disambiguation page Byway A byway in the United Kingdom is a minor secondary or tertiary road The Dwight D Eisenhower National System of Interstate and Defense Highways, commonly called the Interstate Highway System (or simply the Interstate System) The United States of America —commonly referred to as the On divided roads including Expressways Motorways or Autobahns the central reservation (British English, median (North American An expressway is a Divided highway for high-speed traffic with at least partial Control of access. Motorway is a term for both a type of Road and a classification or designation (German ˈaʊtoːbaːn plural Autobahnen; English /ˈɔːtəʊbɑːn/ is the German word for a major high- Speed Road restricted to motor British English or UK English ( BrE, BE, en-GB) is the broad term used to distinguish the forms of the English language used in the North American English is a collective term used for the varieties of the English language that are spoken in North America, namely in the United States Australian English ( AuE, AusE, en-AU) is the form of the English language used in Australia. The word lane has several meanings including and especially a portion of a paved Road which is intended for a single line of vehicles and is marked by White Traffic on Roads may consist of Pedestrians ridden or herded Animals Vehicles Streetcars and other Conveyances either singly In a range of hills or especially of mountains, a pass (also gap, notch, col, saddle, bwlch,
• Pavement - The road regarded as a geoconstruction.
• Pedestrian crossing - Designated point on a road at which some means are employed to assist pedestrians wishing to cross safely
• Private highway - Highway owned and operated for profit by private industry
• Private road - Road owned and maintained by a private individual, organization, or company rather than by a government
• Public space - Place where anyone has a right to come without being excluded because of economic or social conditions
• Ranch road - U.S. road which serves to connect rural and agricultural areas to market towns
• Road number - Often assigned to a stretch of public roadway. Crosswalk button neJPG|right|thumb|The button one pushes to activate the crosswalk signal A private highway is a Highway owned and operated for profit by private industry In Economics, the private sector is that part of the economy which is both run for private Profit and is not controlled by the State. A private road is a road owned and maintained by a private individual organization or company rather than by a government The term person is used in Common sense to mean an individual Human being. An organization (or organisation &mdash see spelling differences) is a social arrangement which pursues collective goals which controls its own performance and Generally a company is a form of Business organization. The precise definition varies For the government of parliamentary systems see Executive (government. A public space refers to an area or place that is open and accessible to all citizens regardless of Gender, Race, Ethnicity, Age or Socioeconomics or socio-economics is the study of the relationship between economic activity and Social life. In the United States, a farm-to-market road or ranch-to-market road (sometimes farm road or ranch road for short is a State road The United States of America —commonly referred to as the Rural areas can be large and isolated (also referred to as "the country" and/or "the countryside over the course of time Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture Market town or market right is a legal term originating in the Medieval period for a European settlement that has the right to hold Markets A road number is often assigned to a stretch of public roadway The number chosen is often dependent on the type of road, with numbers differentiating between interstates, motorways, arterial thoroughfares, and so forth
• Road-traffic safety - Process to reduce the harm (deaths, injuries, and property damage) resulting from crashes of road vehicles traveling on public roads
• Roadworks - Part or all of the road has to be occupied for work or maintenance relating to the road
• Roughness - Deviations from a true planar pavement surface, which affects vehicle suspension deflection, dynamic loading, ride quality, surface drainage and winter operations. Various types of road are in use around the world Roads range in size from private Driveways to the stereotypical two-lane Highway, to high capacity Motorway is a term for both a type of Road and a classification or designation An arterial road is a moderate or high-capacity Road which is immediately below a Highway Level of service. Baustellesvg|thumb]] Roadworks occur when part of the Road, or in rare cases the entire road has to be occupied for work relating to the road most often in the case of road Roughness is a measure of the texture of a Surface. It is quantified by the vertical deviations of a real surface from its ideal form Roughness have wavelengths ranging from 500 mm up to some 40 m. The upper limit may be as high as 350 m when considering motion sickness aspects; motion sickness is generated by motion with down to 0. 1 Hz frequency; in an ambulance car driving 35 m/s (126 km/h), waves with up to 350 m will excite motion sickness.
• Shoulder - Reserved area by the verge of a road, generally it is kept clear of all traffic
• State highway - Road numbered by the state, falling below numbered national highways (like U.S. Routes) in the hierarchy OR A road maintained by the state, including nationally-numbered highways
• Texture (roads) - Deviations from a true planar pavement surface, which affects the interaction between road and tire. A hard shoulder, or simply shoulder, is a reserved area by the verge of a Road or Motorway. State highway, state road or state route can refer to one of three related concepts two of them related to a State government in a country that is divided A state is a political association with effective Sovereignty over a geographic Area and representing a Population. The system of United States Numbered Highways (often called U Microtexture have wavelengths below 0. 5 mm, Macrotexture below 50 mm and Megatexture below 500 mm.
• Traffic calming - Set of strategies used by urban planners and traffic engineers which aim to slow down or reduce traffic, thereby improving safety for pedestrians and bicyclists as well as improving the environment for residents
• Traffic light - also known as a traffic signal, stop light, stop-and-go lights, robot or semaphore, is a signaling device positioned at a road intersection, pedestrian crossing, or other location in order to indicate when it is safe to cross a road

See also

Corpse roads Design Manual for Roads and Bridges Habitat fragmentation Inca road system Line source List of roads and highways List of OECD countries by road network size

Road movie Roadway air dispersion model Roadway noise Street Strip road Towing Trade route

References

External links

• The Post-Roads of Europe 1781 Map
• National Alliance Against Tolls
• The Roadex project

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