Road

RoadA road is an identifiable route, way or path between two or more places. Roads are typically smoothed, paved, or otherwise prepared to allow easy travel; though they need not be, and historically many roads were simply recognizable routes without any formal construction or maintenance. 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. Economics and society depend heavily on efficient roads. 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.

In original usage, a "road" was simply any pathway fit for riding. The word street, whose origin is the Latin strata, was kept for paved pathways that had been prepared to ease travel in some way. Thus, many "Roman Roads" have the word "street" as part of their name. Roads are a prerequisite for road transport of goods on wheeled vehicles.

Words with related usage include, Avenue, Boulevard, Court, Drive, Freeway, Highway, Lane, Street, Turnpike and Way.

That the first pathways were the trails made by animals has not been universally accepted, arguing that animals do not follow constant paths. Others believe that some roads originated from humans following animals trails. The Icknield Way is given as an example of this type road origination were man and animal both selected the same natural line. By about 10,000 BC, rough pathways were used by human travelers.

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 Corduroy road (log road) are found dating to 4,000 BC in Glastonbury, England 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. Built in winter 3807 BC or spring 3806 BC, tree-ring dating (Dendrochronology) enabled very precise dating. It has been claimed to be the oldest road in the world. Brick paved streets were used in India as early as 3000 BC 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. The road remained in use after Roman times. In ancient times, transport by river was far easier and faster than transport by road, especially considering the cost of road construction and the difference in carrying capacity between carts and river barges. 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. From about 312 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, in support of its military campaigns. 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. In the 1600's road construction and maintenance in Britain was traditionally done on a local parish basis. 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. 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.

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 differs from some other branches of economics in that the assumption of a spaceless, instantaneous economy does not hold. 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. 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.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.

Sources

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In transport, demand can be measured in numbers of journeys made or in total distance traveled across all journeys (e.g. passenger-kilometres for public transport or vehicle-kilometres of travel (VKT) for private transport). 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. The effect of increases in supply (capacity) are of particular interest in transport economics (see induced demand), as the potential environmental consequences are significant.

Road building and maintenance is an area of economic activity that remains dominated by the public sector (though often through private contractors). Roads (except those on private property not accessible to the general public) are typically paid for by taxes (often raised through levies on fuel), though some public roads, especially highways are funded by tolls.

Prior to the advent of the internal combustion engine, a principal environmental effect was production of animal excrement from horses, cattle and other animals on drovers' roads and other streets. In the 19th century this issue became significant enough to have some European city officials call for more cleanliness on the roads. Beginning in the 20th century the excrement issue has been overshadowed by vehicle production of noise and air pollution emissions.

Motor vehicle traffic on roads generate noise pollution especially at higher operating speeds. Therefore, considerable noise health effects are expected from road systems used by large numbers of motor vehicles. Noise mitigation strategies exist to reduce sound levels at nearby sensitive receptors. The idea that road design could be influenced by acoustical engineering considerations first arose about 1973.

Motor vehicles operating on roads contribute emissions, particularly for congested city street conditions and other low speed circumstances. Concentrations of air pollutants and adverse respiratory health effects are greater near the road than at some distance away from the road.

Traffic flows on the right or on the left side of the road depending on the country. 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. 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. By roadway distances, about 28% drive on the left, and 72% on the right, even though originally most traffic drove on the left worldwide.

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. (pg15) and may be required to meet standards set by law or official guidelines. 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. A variety of road building equipment is employed in road building.

After design, approval, planning, legal and environmental considerations have been addressed alignment of the road is set out by a surveyor. The Radii and gradient are designed and staked out to best suit the natural ground levels and minimize the amount of cut and fill. (page34) Great care is taken to preserve reference Benchmarks (page59)

Roadways are designed and built for primary use by vehicular and pedestrian traffic. Storm drainage and environmental considerations are a major concern. Erosion and sediment controls are constructed to prevent detrimental effects. 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. 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. (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. Approval from local authorities may be required to draw water or for working (crushing and screening) of materials for construction needs. The top soil and vegetation is removed from the borrow pit and stockpiled for subsequent rehabilitation of the extraction area. Side slopes in the excavation area not steeper than one vertical to two horizontal for safety reasons. (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. 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. The topsoil is usually stripped and stockpiled nearby for rehabilitation of newly constructed embankments along the road. 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. (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. 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. (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. 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. Sand clay fill may also be used. 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. (page 70 to 72 )

The completed road way is finished by paving or left with a gravel or other natural surface. The type of road surface is dependent on economic factors and expected usage. Safety improvements like Traffic signs, Crash barriers, Raised pavement markers, and other forms of Road surface marking are installed.

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 or twinning. 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.

Sometimes, the new carriageway may be constructed along one side of the existing carriageway for some distance, then constructed on the opposite side. When this occurs, the existing carriageway is split and joined to the new sections, with a short section of the old carriageway being torn up and turned into median.

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. 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. A typical tractor-trailer weighing 80,000 pounds with 8,000 pounds on the steer axle and 36,000 pounds on both of the tandem axle groups is expected to do 7,800 times more damage than a passenger vehicle with 2,000 pounds on each axle.

Pavements are designed for an expected service life or design life. In some UK countries the standard design life is 40 years for new bitumen and concrete pavement. Maintenance is considered in the whole life cost of the road with service at 10, 20 and 30 year milestones. 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. 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.

Virtually all roads require some form of maintenance before they come to the end of their service life. Maintenance treatments for asphalt concrete generally include crack sealing, surface rejuvenating, fog sealing, micro-milling and thin surfaceings. 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.

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 Rights of way in the United Kingdom 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. 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.
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.
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'. 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.
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. 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
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
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
United States Numbered Highways - Often called U.S. Routes or U.S. Highways is an integrated system of roads and highways in the United States numbered within a nationwide grid

History Of Road Transport

History Of Road TransportThe history of road transport started with the development of tracks by humans and their beasts of burden.

The first forms of road transport were horses, oxen or even humans carrying goods over tracks that often followed game trails, such as the Natchez Trace. In the Stone Age humans did not need constructed tracks in open country. The first improved trails would have been at fords, mountain passes and through swamps. The first improvements would have consisted largely of clearing trees and big stones from the path. As commerce increased, the tracks were often flattened or widened to accommodate human and animal traffic. Some of these dirt tracks were developed into fairly extensive networks, allowing communications, trade and governance over wide areas. The Incan Empire in South America and the Iroquois Confederation in North America, neither of which had the wheel, are examples of effective use of such paths.

The first goods transport was on human backs and heads, but the use of pack animals, including donkeys and horses, developed during the Stone Age. The first vehicles is believed to have have been the travois, a frame used to drag loads, which probably developed in Eurasia after the first use of bullocks (castrated cattle) for pulling ploughs. In about 5000 BC, sleds developed, which are more difficult to build than travois, but are easier to propel over smooth surfaces. Pack animals, ridden horses and bullocks dragging travois or sleds require wider paths and higher clearances than people on foot and improved tracks were required. As a result by about 5000 BC road developed along the tops of ridge in England, including the Ridgeway, to avoid crossing rivers and bogging.

Harappan roads

Street paving has been found from the first human settlements around 4000 BC in cities of the Indus Valley Civilization on the Indian subcontinent, such as Harrapa and Mohenjo-daro.

Wheeled transport

Wheels appear to have been developed in ancient Sumer in Mesopotamia around 5000 BC, perhaps originally for the making of pottery. Their original transport use may have been as attachments to travois or sleds to reduce resistance. It has been argued that logs were used as rollers under sleds prior to the development of wheels, but there is no archeological evidence for this. Most early wheels appear to have been attached to fixed axles, which would have required regular lubrication by animal fats or vegetable oils or separation by leather to be effective. The first simple two-wheel carts, apparently developed from travois, appear to have been used in Mesopotamia and northern Iran in about 3000 BC and two-wheel chariots appeared in about 2800 BC. They were hauled by onagers, related to donkeys.

Heavy four-wheeled wagons developed about 2500 BC, which were only suitable for oxen-haulage, and therefore were only used where crops were cultivated, particularly Mesopotamia. Two-wheeled chariots with spoked wheels appear to have been developed around 2000 BC by the Andronovo culture in southern Siberia and Central Asia. At much the same time the first primitive harness enabling horse-haulage was invented.

Wheeled-transport created the need for better roads. Generally natural materials cannot be both soft enough to form well-graded surfaces and strong enough to bear wheeled vehicles, especially when wet, and stay intact. In urban areas it began to be worthwhile to build stone-paved streets and, in fact, the first paved streets appear to have been built in Ur in 4000 BC. Corduroy roads were built in Glastonbury, England in 3300 BC and brick-paved roads were built in the Indus Valley Civilization on the Indian subcontinent from around the same time. Improvements in metallurgy meant that by 2000 BC stone-cutting tools were generally available in the Middle East and Greece allowing local streets to be paved. Notably, in about 2000 BC, the Minoans built a 50 km paved road from Knossos in north Crete through the mountains to Gortyn and Lebena, a port on the south coast of the island, which had side drains, a 200 mm thick pavement of sandstone blocks bound with clay-gypsum mortar, covered by a layer of basaltic flagstones and had separate shoulders. This road could be considered superior to any Roman road.

Royal Road

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. The road was used even after the Roman times. Because of the road's superior quality, mail couriers could travel 2,699 km in seven days.

Roman roads

With the advent of the Roman Empire, there was a need for armies to be able to travel quickly from one area to another, and the roads that existed were often muddy, which greatly delayed the movement of large masses of troops. To resolve this issue, the Romans built great roads. The Roman roads used deep roadbeds of crushed stone as an underlying layer to ensure that they kept dry, as the water would flow out from the crushed stone, instead of becoming mud in clay soils. The legions made good time on these roads and some are still used millennia later.

On the more heavily traveled routes, there were additional layers that included six sided capstones, or pavers, that reduced the dust and reduced the drag from wheels. The pavers allowed the Roman chariots to travel very quickly, ensuring good communication with the Roman provinces. Farm roads were often paved first on the way into town, to keep produce clean. Early forms of springs and shocks to reduce the bumps were incorporated in horse drawn transport, as the original pavers were sometimes not perfectly aligned.

New construction methods in the 18th and 19th centuries

Roman roads deteriorated over the Middle Ages because of lack of resources and skills to maintain them, but many continued to be used, and some are still partially used today, for instance, parts of England's A1. As states developed and became richer, especially with the Renaissance, new roads and bridges began to be built, often based on Roman designs. Although there were attempts to rediscover Roman methods, there was little useful innovation in road building before the 18th century.

Between 1725 and 1737 General George Wade constructed 250 miles of road and 40 bridges to improve Britain's control of the Scottish Highlands, using Roman road designs with large stones at the bottom and gravel on top, with a typical overall depth of two metres. They were so poorly aligned and steep, according to Thomas Telford, "as to be unfit for the purposes of civil life" and also rough and poorly drained.

Toll roads

England and Wales Main article: turnpike trust

As traffic levels increased in England and roads deteriorated. Toll roads were built by Turnpike Trusts, especially between 1730-1770. It has been claimed that as a result the time taken between London, to York, Manchester or Exeter was cut by two-thirds between 1720 and 1780. Blind Jack Metcalf (1717-1810) built about 300 km (180 miles) of turnpike road between 1753 abd 1810, mainly in Lancashire, Derbyshire, Cheshire and Yorkshire. He understood the importance of good drainage and surfaced his roads with "a compact layer of small, broken stones with sharp edges", rather than the naturally rounded stones traditionally used in European road building. British turnpike builders began to realise the importance of selecting clean stones for surfacing, and excluding vegetable material and clay to make better lasting roads.

United States of America

Turnpikes were also later built in the United States. They were usually built by private companies under a government franchise. They typically paralleled or replaced routes already with some volume of commerce, hoping the improved road would divert enough traffic to make the enterprise profitable. Plank roads were particularly attractive as they greatly reduced rolling resistance and mitigated the problem of getting mired in mud. Another improvement, better grading to lessen the steepness of the worst stretches, allowed draft animals to haul heavier loads.

Water transport on rivers and canals carried many farm goods from the frontier U.S. (between the Appalachian mountains and Mississippi River) in the early 19th century, but the shorter route over the mountains had advantages. Successful farms created a demand for imported and manufactured goods from the Atlantic coast. The commercial interests of the East were quick to see the possibilities of this new market. An eager rivalry sprung up between the merchants of New York, Philadelphia, and Baltimore. Everywhere ways and means of cheaper transportation were discussed. In this subject the western farmer was vitally interested, for freight charges added nearly one third to the cost of merchandise transported over the mountains. The cotton planter of the Seaboard States, also, feeling the competition of the Southwest, where riverways were abundant and easily navigable, saw the need of better roads to tidewater, in order to lessen the cost of marketing his produce.

The popular demand for better roads was not recent. All the states had encouraged, directly or indirectly, the building of turnpikes and bridges. Between 1793 and 1812, Pennsylvania had chartered fifty-five turnpike companies, and other states had been scarcely less ready to grant articles of incorporation to stock companies. Private enterprise had, indeed, done much to improve communication along the seaboard. Turnpikes and bridges had shortened the journey by stage from Boston to Washington to four and a quarter days by the year 1815.

The magnitude of the transportation problem was such, however, that neither individual states nor private corporations seemed able to meet the demands of an expanding internal trade. As early as 1807, Albert Gallatin had advocated the construction of a great system of internal waterways to connect East and West, at an estimated cost of $20,000,000. But the only contribution of the national government to internal improvements during the Jeffersonian era was an appropriation in 1806 of two percent of the net proceeds of the sales of public lands in Ohio for the construction of a national road, with the consent of the states through which it should pass. By 1818 the road was open to traffic from Cumberland, Maryland, to Wheeling, West Virginia.

In 1816, with the experiences fo the war before him, no well-informed statesman could shut his eyes to the national aspects of the problem. Even President Madison invited the attention of Congress to the need of establishing "a comprehensive system of roads and canals". Soon after Congress met, it took under consideration a bill drafted by Calhoun which proposed an appropriation of $1,500,000 for internal improvements. Because this appropriation was to be met by the moneys paid by the National Bank to the government, the bill was commonly referred to as the "Bonus Bill". But on the day before he left office, President Madison vetoed the bill because it was unconstitutional. The policy of internal improvements by federal aid was thus wrecked on the constitutional scruples of the last of the Virgina dynasty. Having less regard for consistency, the House of Representatives recorded its conviction, by close votes, that Congress could appropriate money to construct roads and canals, but had not the power to construct them. As yet the only direct aid of the national government to internal improvements consisted of various appropriations, amounting to about $1,500,000 for the Cumberland Road.

As the country recovered from financial depression following the Panic of 1819, the question of internal improvements again forged to the front. IN 1822, a bill to authorize the collection of tolls on the Cumberland Road had been vetoed by the President. In an elaborate essay Monroe set forth his views on the constitutional aspects of a policy of internal improvements. Congress might appropriate money, he admitted, but it might not undertake the actual construction of national works nor assume jurisdiction over them. For the moment the drift toward a larger participation of the national government in internal improvements was stayed. Two years later, Congress authorized the President to institute surveys for such roads and canals as he believed to be needed for commerce and military defense. No one pleaded more eloquently for a larger conception of the functions of the national government than Clay. He called the attention of his hearers to provisions made for coast surveys and lighthouses on the Atlantic seaboard and deplored the neglect of the interior of the country. Of the other presidential candidates, Jackson voted in the Senate for the general survey bill; and Adams left no doubt in the public mind that he did not reflect the narrow views of his section on this issue. Crawford felt the constitutional scruples which were everywhere being voiced in the South, and followed the old expedient of advocating a constitutional amendment to sanction national internal improvements.

In President Adams' first message to Congress, he advocated not only the construction of roads and canals but also the establishment of observatories and a national university. President Jefferson had recommended many of these in 1806 for Congress to consider for creation of necessary amendments to the Constitution. Adams seemed oblivious to the limitations of the Constitution. In much alarm Jefferson suggested to Madison the desirability of having Virginia adopt a new set of resolutions, bottomed on those of 1798, and directed against the acts for internal improvements. In March, 1826, the general assembly declared that all the principles of the earlier resolutions applied "will full force against the powers assumed by Congress" in passing acts to protect manufacturers and to further internal improvements. That the Administration would meet with opposition in Congress was a foregone conclusion.

Tr?saguet's work in France

In France, Pierre-Marie-J?r?me Tr?saguet is widely credited with establishing the first scientific approach to road building about the year 1764. He wrote a memorandum on his method in 1775, which became general practice in France. It involved a layer of large rocks, covered by a layer of smaller gravel. The lower layer improved on Roman practice in that it was based on the understanding that the purpose of this layer (the sub-base or base course) is to transfer the weight of the road and its traffic to the ground, while protecting the ground from deformation by spreading the weight evenly. Therefore, the sub-base did not have to be a self-supporting structure. The upper running surface provided a smooth surface for vehicles, while protecting the large stones of the sub-base. Tr?saguet understood the importance of drainage by providing deep side ditches, but he insisted on building his roads in trenches, so that they could be accessed from the sides, which undermined this principle. Well-maintained surfaces and drains protect the integrity of the sub-base and Tr?saguet introduced a system of continuous maintenance, where a roadman was allocated a section of road to be kept up to a standard.

Developments in England

Telford

Thomas Telford (1757-1834) also made substantial advances in the engineering of new roads and the construction of bridges. Under his supervision 1,500 km of roads and 1,000 bridges were built in Scotland between 1802 and 1822. He elaborated Tr?saguet method by a more complex and costly system of stonework in the subgrade, but his main improvement over Tr?saguet was the raising of his roads above the natural level to improve drainage or the drainage of the area around the road.

McAdam

John Loudon McAdam (1756-1836) designed the first modern highways. He developed an inexpensive paving material of soil and stone aggregate (known as macadam), and he embanked roads a few feet higher than the surrounding terrain to cause water to drain away from the surface. He had noticed in his observations that coaches with narrow, iron-tyred wheels and moving at relatively high speed were causing significant damage to roads, but that areas of small broken stones were most resistant to damage, while the areas that had large surface stones degraded fastest. His solution was to create roads with 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 (75 mm), to a total depth of about 8 inches (200 mm). The third layer was about 2 inches (50 mm) thick with a maximum aggregate size of 1 inch (25 mm). Each layer would be compacted with a heavy roller, causing the angular stones to lock together with their neighbours. It is possible that his initial decision not to use the heavy layer of base stones used by Telford in his subgrade reflected lack of suitable stones, but McAdam quickly saw they were not necessary. In practice, his roads proved to be twice as strong as Telford's roads. He also inisisted on raising the roads to ensure good trainage and flat crowned surfaces, rather than ridges built into the road to encourage drainage.

McAdam was adamantly opposed to the filling of the voids between his small cut stones with smaller material, possibly as a reaction against the use of poor materials, including soil and vegetable matter, on roads in the past. Nevertheless, in practice road builders began to introduce filler materials such as smaller stones, sand and clay, and it was observed that these roads were stronger as a result. Macadam roads were being built widely in the United States and Australia in the 1820s and in Europe in the 1830s and 1840s.

Development of paved roads

Various systems had been developed over centuries to reduce washways, bogging and dust in cities, including cobblestones and wooden paving. Tar-bound macadam (tarmac) was applied to macadam roads towards the end of the 19th century in cities such as Paris. In the early 20th century tarmac and concrete paving were extended into the countryside.

Incidentally, bicyclists were among the early campaigners on what was called the Good Roads Movement. Bicycling was an extremely popular recreation among the middle and upper classes in the late 19th century and was more fun on paved roads.

Roadway Air Dispersion Modeling

Roadway Air Dispersion ModelingRoadway air dispersion modeling is the study of air pollutant transport from a roadway or other linear emitter. Computer models are required to conduct this analysis, because of the complex variables involved, including vehicle emissions, vehicle speed, meteorology, and terrain geometry. Line source dispersion has been studied since at least the 1960s, when the regulatory framework in the United States began requiring quantitative analysis of the air pollution consequences of major roadway and airport projects. By the early 1970s this subset of atmospheric dispersion models were being applied to real world cases of highway planning, even including some controversial court cases.

How the model works

The basic concept of the roadway air dispersion model is to calculate air pollutant levels in the vicinity of a highway or arterial roadway by considering them as line sources. The model takes into account source characteristics such as traffic volume, vehicle speeds, truck mix, and fleet emission controls; in addition, the roadway geometry, surrounding terrain and local meteorology are addressed. For example, many air quality standards require that certain near worst case meteorological conditions be applied.

The calculations are sufficiently complex that a computer model is essential to arrive at authoritative results, although workbook type manuals have been developed as screening techniques. In some cases where results must be refereed (such as legal cases), model validation may be needed with field test data in the local setting; this step is not usually warranted, because the best models have been extensively validated over a wide spectrum of input data variables.

The product of the calculations is usually a set of isopleths (air pollution contour maps), either in plan view or cross sectional view. Typically these might be stated as concentrations of carbon monoxide, total reactive hydrocarbons, oxides of nitrogen, particulate or benzene. The air quality scientist can run the model successively to study techniques of reducing adverse air pollutant concentrations (for example, by redesigning roadway geometry, altering speed controls or limiting certain types of trucks). The model is frequently utilized in an Environmental Impact Statement involving a major new roadway or land use change which will induce new vehicular traffic.

History

The logical building block for this theory was the use of the Gaussian air pollutant dispersion equation for point sources . One of the early point source air pollutant plume dispersion equations was derived by Bosanquet and Pearson in 1936. Their equation did not include the effect of ground reflection of the pollutant plume. Sir Graham Sutton derived a point source air pollutant plume dispersion equation in 1947 which included the assumption of Gaussian distribution for the vertical and crosswind dispersion of the plume and also addressed the effect of ground reflection of the plume. Further advances were made by G. A. Briggs in model refinement and validation and by D.B. Turner for his user-friendly workbook that included screening calculations which do not require a computer.

In seeing the need to develop a line source model to approach the study of roadway air pollution, Michael Hogan and Richard Venti developed a closed form solution to integrating the point source equation in a series of publications.

While the ESL mathematical model was completed for a line source by 1970, model refinement resulted in a strip source, emulating the horizontal extent of the roadway surface. This theory would be the precursor of area source dispersion models. But their focus was roadway simulation, so they proceeded with the development of a computer model by adding to the team Leda Patmore, a computer programmer in the field of atmospheric physics and satellite trajectory calculations. A working computer model was produced by late 1970; then the model was calibrated with carbon monoxide field measurements targeting from traffic on U.S. Route 101 in Sunnyvale, California.

The ESL model received endorsement from the U.S. Environmental Protection Agency (EPA) in the form of a major grant to validate the model using actual roadway tests of tracer gas sulfur hexafluoride dispersion. That gas was chosen since it does not occur naturally or in vehicular emissions and provides a unique tracer for such dispersion studies. Part of the Environmental Protection Agencys motives may have been to bring the model into public domain. After a successful validation through the EPA research, the model was soon put to use in a variety of settings to forecast air pollution levels in the vicinity of roadways. The ESL group applied the model to the U.S. Route 101 bypass project in Cloverdale, California, the extension of Interstate 66 through Arlington, Virginia, the widening of the New Jersey Turnpike through Raritan and East Brunswick, New Jersey, and several transportation projects in Boston for the Boston Transportation Planning Review.

By the early 1970s at least two other research groups were known to be actively developing some type to roadway air dispersion model: the Environmental Research and Technology group of Lexington, Massachusetts and CalTrans headquarters in Sacramento, California. The Caline model of Caltrans borrowed some of the technology from the ESL Inc. group, since CalTrans funded some of the early model application work in Cloverdale and other locations and was given rights to use parts of their model.

There were several early applications of the model in somewhat dramatic cases. In 1971 the Arlington Coalition on Transportation (ACT) was the plaintiff in an action against the Virginia Highway Commission over the extension of Interstate 66 through Arlington, Virginia , having filed a suit in the U.S. District Court. The ESL model was used to produce calculations of air quality in the vicinity of the proposed highway. ACT won this case after a decision by the U.S. Fourth Circuit Court of Appeals. The court paid special attention to the plaintiff's expert calculations and testimony projecting that air quality levels would violate Federal ambient air quality standards as set forth in the Clean Air Act.

A second contentious case took place in East Brunswick, New Jersey where the New Jersey Turnpike Authority planned a major widening of the Turnpike. Again the roadway air dispersion model was employed to predict levels of air pollution for residences, schools and parks near the Turnpike. After an initial hearing in Superior Court where the ESL model results were set forth, the judge ordered the Turnpike Authority to negotiate with the plaintiff, Concerned Citizens of East Brunswick and develop air quality mitigation for the adverse effects. The Turnpike Authority hired ERT as its expert, and the two research teams negotiated a settlement to this case using the newly created roadway air dispersion models.

The CALINE3 model is a steady-state Gaussian dispersion model designed to determine air pollution concentrations at receptor locations downwind of highways located in relatively uncomplicated terrain. CALINE3 is incorporated into the more elaborate CAL3QHC and CAL3QHCR models. CALINE3 is in widespread use due to its user friendly nature and promotion in governmental circles, but it falls short of analyzing the complexity of cases addressed by the original Hogan-Venti model . CAL3QHC and CAL3QHCR models are available in fortran programming language and are limited to carbon monoxide: they do, however, include an embedded traffic model to better assess dynamic features such as stalling traffic .

In addition, several more recent models have been developed that employ non-steady state Lagrangian puff algorithms. The HYROAD dispersion model has been developed through the National Cooperative Highway Research Program's Project 25-06, incorporating ROADWAY-2 model puff and steady-state plume algorithms (Rao et al., 2002), in addition to the Federal Highway Administration's NETSIM traffic microsimulation model. Unfortunately, due to changes in the Windows operating system, the platform upon which HYROAD was developed, the NETSIM component of HYROAD can only operate on Windows 98 (or earlier) operating systems. The problem stems from the loss of the original model code for NETSIM by its developers, preventing it from being compiled on other operating systems. EPA contends that HYROAD is appropriate for modeling ambient concentrations of carbon monoxide, particulate matter, and air toxics.

The TRAQSIM model, developed as part of a Ph.D dissertation with support by the U.S. Department of Transportation's Volpe National Transportation Systems Center's Air Quality Facility is currently under the care of Wyle Laboratories. The model incorporates dynamic vehicle behavior with a non-steady state Gaussian puff algorithm. Unlike HYROAD, TRAQSIM combines traffic simulation, second-by-second modal emissions, and Gaussian puff dispersion into a fully integrated system (a true simulation) that models individual vehicles as discrete moving sources. TRAQSIM was developed as a next generation model to be the successor to the current CALINE3 and CAL3QHC regulatory models. The next step in the development of TRAQSIM is to incorporate methods to model the dispersion of particulate matter (PM) and hazardous air pollutants (HAPs).

Several models have been developed that handle complex urban meteorology resulting from urban canyons. Examples include the Turner-Fairbank Highway Research Center'sCanyon Plume Box model, now in version 3 (CPB-3), the National Environmental Research Institute of Denmark's Operational Street Pollution Model (OSPM), and the MICRO-CALGRID model, which includes photochemistry, allowing for both primary and secondary species to be modeled.

Recent health literature indicating that residents near major roads face elevated rates of several adverse health outcomes has prompted legal dispute over the responsibility of transportation agencies to use roadway air dispersion models to characterize the impacts of new and expanded roadways, bus terminals, truck stops, and other sources.

Recently, the Sierra Club of Nevada sued the Nevada Department of Transportation and the Federal Highway Administration over its their failure to assess the impact of the expansion of US-95 in Las Vegas on neighborhood air quality. The Sierra Club asserted that a supplemental Environmental Impact Statement should be issued to address emissions of hazardous air pollutants and particulate matter from new motor vehicle traffic. The plaintiffs asserted that modeling tools were available, including the Environmental Protection Agency's MOBILE6.2 model, the CALINE3 dispersion model, and other relevant models. The defendants won in the U.S. District Court under Judge Philip Pro, who ruled that the transportation agencies had acted in a manner that was not "arbitrary and capricious," despite the agencies' technical arguments regarding the lack of available modeling tools being contradicted by a number of peer-reviewed studies published in scientific journals (e.g. Korenstein and Piazza, Journal of Environmental Health, 2002). On appeal to the 9th Federal Circuit Court, the court stayed new construction on the highway pending the court's final decision. The Sierra Club and the defendants settled out of court, setting up a research program on the air quality impacts of US-95 on nearby schools.

A number of other high-profile cases have prompted environmental groups to call for dispersion modeling to be used to assess the air quality impacts of new transportation projects on nearby communities, but to date state transportation agencies and the Federal Highways Administration has claimed that no tools are available, despite models and guidance available through EPA's Support Center for Regulatory Air Models (SCRAM).

Among the more contentious of cases the Detroit Intermodal Freight Terminal and Detroit River International Crossing (Michigan, USA), and the expansion of Interstate 70 East in Denver (Colorado , USA).

In all of these cases, community-based organizations have asserted that modeling tools are available, but transportation planning agencies have asserted that too much uncertainty exits in all of the steps. A major concern for community-based organizations has been transportation agencies' unwillingness to define the level of uncertainty that they are willing to tolerate in air quality analyses, how that compares to the Environmental Protection Agency's guideline on air quality models, which addresses uncertainty and accuracy in model use.

Roadway Noise

Roadway NoiseRoadway noise is the collective sound energy emanating from motor vehicles. In the USA it contributes more to environmental noise exposure than any other noise source, and is constituted chiefly of engine, tire, aerodynamic and braking elements. In other Western countries as well as Lesser developed countries, roadway noise is expected to contribute a proportionately large share of the total societal noise pollution.

Roadway noise began to be measured in a widespread manner in the 1960s, when computer modeling of this phenomenon was perfected. After passage of the National Environmental Policy Act and Noise Control Act, the demand for detailed analysis soared, and decision makers began to look to acoustical scientists for answers regarding the planning of new roadways and the design of noise mitigation.

Partial bans on motor vehicles from urban areas have been shown to have minimal impacts upon reducing sound levels (as would become clear from later modeling studies); for example, the partial ban in Gothenburg, Sweden resulted in minuscule reduction of sound levels.

The intensity of roadway noise is governed by the following variables: traffic operations (speed, truck mix, age of vehicle fleet), roadway surface type, tire types, roadway geometrics, terrain, micrometeorology and the geometry of area structures.

Traffic operations noise is affected significantly by vehicle speeds, since sound energy roughly doubles for each increment of ten miles an hour in vehicle velocity; an exception to this rule occurs at very low speeds where braking and acceleration noise dominate over aerodynamic noise. Small reductions in vehicle noise occurred in the 1970s as states and provinces enforced unmuffled vehicle ordinances. The vehicle fleet noise has not changed very much over the last three decades; however, if the trend in hybrid vehicle use continues, substantial noise reduction will occur, especially in the regime of traffic flow below 35 miles per hour. As a pedestrian safety issue, hybrid vehicles are so quiet at low speeds that the customary warning noise may not alert the pedestrian to nearby danger, creating a potential hazard for visually-impaired people, who rely on such noise to navigate in areas of heavy traffic. Trucks contribute a disproportionate amount of noise not only because of their large engines, but also the height of the diesel stack and the aerodynamic drag. Significant interior noise is usually present inside moving motor vehicles; in fact, passengers are generally not aware that these levels are high, because experience has led motorists to expect levels commonly exceeding 65 dBA.

Roadway surface types contribute differential noise effects of up to 4 dB, with chip seal type and grooved roads being the loudest and concrete surfaces without spacers being the quietest. Asphaltic surfaces are about average.

Tire types had considerable design changes in the 1970s, and at this juncture are probably optimized for noise control, given the of safety needs for a significant grip by the tread.

Roadway geometrics and surrounding terrain are interrelated, since the propagation of sound is sensitive to the overall geometry and must consider diffraction (bending of sound waves around obstacles), reflection, ground wave attenuation, spreading loss and refraction. A simple discussion indicates that sound will be diminished when the path of sound is blocked by terrain, or will be enhanced if the roadway is elevated so as to broadcast; however, the complexities of variable interaction are so great, that there are many exceptions to this simple argument.

Micrometeorology is significant in that sound waves can be refracted by wind gradients or thermoclines, effectively dismissing the effect of some sound barriers or terrain intervention.

Geometry of area structures is an important input, since the presence of buildings or walls can block sound under certain circumstances, but reflective properties can augment sound energy at other locations.

Because of the complexity of the variables discussed, it is necessary to create a computer model that can analyze sound levels in the vicinity of roadways. The first meaningful models arose in the late 1960s and early 1970s addressing the noise line source (e.g. roadway). Two of the leading research teams were BBN in Boston and ESL of Sunnyvale, California. Both of these groups developed complex mathematical models to allow the study of alternate roadway designs, traffic operations and noise mitigation strategies in an arbitrary setting. Later model alterations have come into widespread use among state Departments of Transportation and city planners, but the accuracy of early models has had little change in 40 years.

Generally the models trace sound ray bundles and calculate spreading loss along with ray bundle divergence (or convergence} from refractive phenomena. Diffraction is usually addressed by establishing secondary emitters at any points of topographic or anthropomorphic sharpness (such as noise barriers or building surfaces). Meteorology can be addressed in a statistical manner allowing for actual wind rose and wind speed statistics (along with thermocline data).

An interesting early case where two of the leading models were pitted against each other involved a proposed widening of the New Jersey Turnpike from six to twelve lanes. The BBN and ESL models were on opposing sides of a matter decided in New Jersey Superior Court. This case in the early 1970s was one of the first U.S. examples of acoustical scientists playing a role in the design of a major highway. The models allowed the court to understand the effects of roadway geometry (width in this case), vehicle speeds, proposed noise barriers, residential setback and pavement types. The outcome was a compromise that involved substantial mitigation of noise pollution impacts.

Another early case involved the proposed extension of Interstate 66 through Arlington, Virginia. The plaintiff, Arlington Coalition on Transportation sued the Virginia Department of Transportation on the grounds of air quality, noise and neighborhood disruption. To analyze roadway noise, the ESL model was used by the plaintiff, who won this case partially due to the credibility of the computer model. The matter was revisited a decade later and a greatly reduced highway design with transit element and extensive noise mitigation was agreed to.

Later cases have occurred in every state, both in contentious actions and in routine highway planning and design. The public as well as governmental agencies have become aware of the value of acoustical science to provide useful insights to the roadway design process.

European technology began to emulate the United States treatment of roadway noise by the 1980s, although the national requirements of noise studies generally remain less stringent than the U.S. In developing countries noise pollution from motor vehicles represents a significant impact, but technologies are not as advanced as in Western nations. For example, a recent paper from Iran illustrates a level of technology that the United States encountered in the 1960s. The European Union has recently proposed a set of vehicle tire requirements, similar to those introduced in the U.S. in the 1970s.

Trade Routes

Trade RoutesTrade routes are logistical networks identified as a series of pathways and stoppages used for the commercial transport of cargo. Connecting public markets to the producers of finished products, a single trade route contains long distance arteries which may further be connected to several smaller networks of commercial and non commercial transportation.

Historically, the period from 1500 BCE-1 CE saw the Western Asian, Mediterranean, Chinese and Indian societies develop major transportation networks for trade. Europe's early trading routes included the Amber Road, which served as dependable networks for long distance trade. Maritime trade along the Spice route became prominent during the middle ages; nations resorted to military means for control of this influential route. During the middle ages organizations such as the Hanseatic League , aimed at protecting interests of the merchants and trade, also became increasingly prominent.

With the advent of modern times, commercial activity shifted from the major trade routes of the Old World to newer routes between modern nation states. This activity was sometimes carried out without traditional protection of trade and under international free trade agreements, which allowed commercial goods to cross borders with relaxed restrictions. Innovative transportation of the modern times includes pipeline transport, and the relatively well known trade using rail routes, automobiles and cargo airlines.

Trading networks of the Old World included the Grand Trunk Road of India and the Incense Road of Arabia. The peninsula of Anatolia lay on the commercial land routes to Europe from Asia as well as the sea route from the Mediterranean to the Black Sea. Records from the 19th century BCE attest to the existence of an Assyrian merchant colony at Kanesh in Cappadocia (now in modern Turkey). The domestication of the camel allowed Arabian nomads to control the long distance trade in spices and silk from the Far East to the Arabian Peninsula. The Egyptians had trade routes through the Red sea, importing spices from the "Land of Punt" (East Africa) and from Arabia.

The Incense Route served as a channel for trading of Indian, Arabian and East Asian goods. The incense trade flourished from South Arabia to the Mediterranean between roughly the 3rd century BCE to the 2nd century CE. This trade was crucial to the economy of Yemen and the frankincense and myrrh trees were seen as a source of wealth by the its rulers.

Ptolemy II Philadelphus, emperor of Ptolemaic Egypt, may have forged an alliance with the Lihyanites in order to secure the incense route at Dedan, thereby rerouting the incense trade from Dedan to the coast along the Red Sea to Egypt. I. E. S. Edwards connects the Syro-Ephraimite War to the desire of the Israelites and the Aramaeans to control the northern end of the Incence route, which ran up from Southern Arabia and could be tapped by commanding Transjordan.

Gerrha, inhabited by Chaldean exiles from Babylon, controlled the Incense trade routes across Arabia to the Mediterranean and exercised control over the trading of aromatics to Babylon in the 1st century BC. The Nabateans exercised control over the routes along the Incense Route. In order to release the Incense Route from the Nabatean control military expeditions were undertaken, without success, by Antigonus Cyclops, emperor of Syria and Palestine. The Nabatean control over trade increased and spread in many directions.

The replacement of Greece by the Roman empire as the administrator of the Mediterranean basin led to the resumption of direct trade with the East and the elimination of the taxes extracted previously by the middlemen of the south. The Romans sacked Ptolemaic Egypt and controlled trade with India. The monopoly of the middlemen weakened with the development of monsoon trade, forcing the Parthian and Arabian middlemen to adjust their prices so as to compete on the Roman market with the goods now being bought in by a direct sea route to India. Indian ships sailed to Egypt as the maritime routes of Southern Asia were not under the control of a single power.

Silk Route Main article: Silk Road

The Silk road was one of the first trade routes to join the Eastern and the Western worlds. According to Vadime Elisseeff (2000):

Along the Silk Roads, technology traveled, ideas were exchanged, and friendship and understanding between East and West were experienced for the first time on a large scale. Easterners were exposed to Western ideas and life-styles, and Westerners too, learned about Eastern culture and its spirituality-oriented cosmology. Buddhism as an Eastern religion received international attention through the Silk Roads.

Cultural interactions patronized often by powerful emperors, such as Kanishka, led to development of art due to introduction of a rich variety of influences. Buddhist missions thrived along the Silk Roads, partly due to the conducive intermixing of trade and cultural values, which created a series of safe stoppages for both the pilgrims and the traders. Among the frequented routes of the Silk Route was the Burmese route extending from Bhamo, which served as a path for Marco Polo's visit to Yunnan and Indian Buddhist missions to Canton in order to establish Buddhist monasteries. This route often under the presence of hostile tribes also finds mention in the works of Rashid al-Din.

Grand Trunk Road Main article: Grand Trunk Road

The Grand Trunk Road connecting Calcutta in India to Peshawar in Pakistan has existed for over two and a half millennia. One of the important trade routes of the world, this road has been a strategic artery with fortresses, halting posts, wells, post offices, milestones and other facilities. Part of this road through Pakistan also coincided with the Silk Road.

This highway has been associated with emperors Chandragupta Maurya and Sher Shah Suri, the latter became synonymous with this route due to his role in ensuring the safety of the travelers and the upkeep of the road. Emperor Sher Shah widened and realigned the road to other routes, and provided approximately 1700 roadside inns through his empire. These inns provided free food and lodgings to the travelers regardless of their status.

The British occupation of this road was of special significance for the British Raj in India. Bridges, pathways, newer inns were constructed by the British for the first thirty seven years of their reign since the occupation of Punjab in 1849. The British followed roughly the same alignment as the old routes, and at some places the newer routes ran parallel to the older routes.

Vadime Elisseeff (2000) comments on the Grand Trunk Road:

Along this road marched not only the mighty armies of conquerers, but also the caravans of traders, scholars, artists, and common folk. Together with people, moved ideas, languages, customs, and cultures, not just in one, but in both directions. At different meeting places permanent as well as temporary people of different origins and from different cultural backgrounds, professing different faiths and creeds, eating different foods, wearing different clothes, and speaking different languages and dialects would meet one another peacefully. They would understand one another's food, dress, manner, and etiquette, and even borrow words, phrases, idioms and, at times, whole languages from others.

The Amber Road was a European trade route associated with the trade and transport of amber. Amber satisfied the criteria for long distance trade as it was light in weight and in high demand for ornamental purposes around the Mediterranean. Before the establishment of Roman control over areas such as Pannonia, the Amber Road was virtually the only route available for long distance trade.

Towns along the Amber Road began to rise steadily during the first century, despite the troop movements under Titus Flavius Vespasianus and his son Titus Flavius Domitianus. Under the reign of Tiberius Caesar Augustus, the Amber Road was straightened and paved according to the prevailing urban standards. Roman towns began to appear along the road, initially founded near the site of Celtic oppida.

The third century saw the Danube river become the principal artery of trade, eclipsing the Amber Road and other commercial routes. The redirection of investment to the Danubian forts saw the towns along the Amber Road growing slowly, though yet retaining their prosperity. The prolonged struggle between the Romans and the barbarians further left its mark on the towns along the Amber Road.

Via Maris, literally Latin for "the way of the sea," was an ancient highway used by the Romans and the Crusaders. The states controlling the Via Maris were in a position to grant access for trade to their own citizens and collect tolls from the outsiders to maintain the trade route. The name Via Maris is a Latin translation of a Hebrew phrase related to Isaiah. Due to the Biblical significance many attempts have been made by the Christian pilgrims in order to locate the route, among other Biblical sites. 13th century traveler and pilgrim Burchard of Mount Zion refers to the Via Maris route as a way leading along the shore of the Sea of Galilee.

As trade between India and the Greco-Roman world increased spices became the main import from India to the Western world, bypassing silk and other commodities. The Indian commercial connection with South East Asia proved vital to the merchants of Arabia and Persia during the seventh century and the eighth century.

The Abbasids used Alexandria, Damietta, Aden and Siraf as entry ports to India and China. Merchants arriving from India in the port city of Aden payed tribute in form of musk, camphor, ambergris and sandalwood to Ibn Ziyad, the sultan of Yemen. Moluccan products shipped across the ports of Arabia to the Near East passed through the ports of India and Sri Lanka. Indian exports of spices find mention in the works of Ibn Khurdadhbeh (850), al-Ghafiqi (1150 AD), Ishak bin Imaran (907) and Al Kalkashandi (fourteenth century). After reaching either the Indian or the Sri Lankan ports were sometimes shipped to East Africa, where they would be used for many purposes, including burial rites.

On the orders of Manuel I of Portugal, four vessels under the command of navigator Vasco da Gama rounded the Cape of Good Hope, continuing to the eastern coast of Africa to Malindi to sail across the Indian Ocean to Calicut. The wealth of the Indies was now open for the Europeans to explore; the Portuguese Empire was one of the early European empires to grow from spice trade.

Hanseatic trade

Shortly before the twelfth century the Germans played a relatively modest role in the north European trade. With the development of Hanseatic trade German traders became prominent in the Baltic and the North Sea regions. Following the death king Eric Menved, German forces attacked and sacked Denmark. The new administration bought artisans and merchants with them and controlled the Hansa regions. During the third quarter of the fourteenth century the Hanseatic trade faced two major difficulties: economic conflict with the Flanders and hostilities with Denmark. These events led to the formation of an organized association of Hanseatic towns, which replaced the earlier union of German merchants.

This new Hansa of the towns, aimed at protecting interests of the merchants and trade, became prominent for the next hundred and fifty years.

Philippe Dollinger associates the downfall of the Hansa to a new alliance between Lubeck, Hamburg and Bremen, which outshadowed the older institution. He further sets the date of dissolution of the Hansa at 1630. The Hansa was almost entirely forgotten by the end of the eighteenth century. Georg Friedrich Sartorius published the first monograph regarding the community in the early years of the nineteenth century.

The modern times saw development of newer means of transport and free trade agreements which altered the political and logistical approach prevalent during the middle ages. Newer means of transport led to the establishment of new routes, and countries opened up borders to allow trade in mutually agreed goods as per the prevailing free trade agreement. Some old trading route were reopened during the modern times, although in different political and logistical scenarios.

The 1844 Railway act of England compelled at least one train to a station every day with the third class fares priced at a penny a mile. Trade benefited as the workers and the lower classes had the ability to travel to other towns frequently. Suburban communities began to develop and towns began to spread outwards. The British constructed a vast railway network in India, but it was considered to serve a strategic purpose in addition to the commercial purpose.

The modern times saw nations struggle for the control of rail routes. The unification of the United States of America was helped by the efficient use of railways. The Trans-Siberian Railway was intended to be used by the Russian government for control of Manchuria and later China; the German forces wanted to establish Berlin-Baghdad Railway in order to influence the Near East; and the Austrian government planned a route from Vienna to Salonika for control of the Balkans.

The Baku-Tbilisi-Ceyhan pipeline connects the modern nation states of Azerbaijan, Georgia and Turkey through a buried pipeline. With a capacity to export one million barrels of oil a day, it has pump stations in all the three countries. Other examples of pipeline transport include Alashankou-Dushanzi Crude Oil Pipeline and Iran-Armenia Natural Gas Pipeline.

Historically, governments followed a policy of protection of trade. International Free Trade became visible in 1860 with the Anglo-French commercial treaty and the sentiment further gained momentum during the post Second World War era. On May 2004, the United States of America signed the American Free trade Agreement with five Central American nations.

According to The Columbia Encyclopedia, Sixth Edition:

After World War II, strong sentiment developed throughout the world against protection and high tariffs and in favor of freer trade. The results were new organizations and agreements on international trade such as the General Agreement on Tariffs and Trade (1948), the Benelux Economic Union (1948), the European Economic Community (Common Market, 1957), the European Free Trade Association (1959), Mercosur (the Southern Cone Common Market, 1991), and the World Trade Organization (1995). In 1993 the North American Free Trade Agreement (NAFTA) was approved by the governments of Canada, Mexico, and the United States. In the early 1990s the nations of the European Union (the successor organization to the Common Market) undertook to remove all barriers to the free movement of trade and employment across their mutual borders.

Express delivery through international cargo airlines touched US $ 20 billion in 1998 and, according to the World Trade Organization, is expected to triple in 2015. In 1998, 50 pure cargo service companies operated internationally.

Corpse Road

Corpse RoadCorpse roads provided a practical means of allowing the transport of corpses to cemeteries that had burial rights. In Britain, such routes can also be known by a number of other names: bier road, burial road, coffin road, coffin line, lyke or lych way, funeral road, procession way, etc. Such "church-ways" have developed a great deal of associated folklore regarding wraiths, spirits, ghosts, and such-like.

In late medieval times a population increase and a concomitant expansion of church building took place in Great Britain inevitably encroaching on the territories of existing mother churches or minsters. Demands for autonomy from outlying settlements made minster officials feel that their authority was waning, as were their revenues, so they instituted corpse roads connecting outlying locations and their mother churches (at the heart of parishes) that alone held burial rights. For some parishioners, this decision meant that corpses had to be transported long distances, sometimes through difficult terrain and usually it had to be carried unless the departed was a wealthy individual. An example would be the funeral way that runs from Rydal to Ambleside in the Lake District where a coffin stone, on which the coffin was placed while the parishoners rested, still exists. Many of the 'new' churches were eventually granted burial rights and corpse roads ceased to be used as such.

Many of the corpse roads have long disappeared, while the original purposes of those that still survive as footpaths have been largely forgotten, especially if features such as coffin stones or crosses no longer exist. Fields crossed by church-way paths often had names like Church-way or Kirk-way Field, and today it is sometimes possible to plot the course of some lost church-ways by the sequence of old field names, local knowledge of churches, local legends and lost features of the landscape marked on old maps, etc. One of the oldest superstitions is that any land over which a corpse is carried becomes a public right of way.

An example of a corpse road or way is that of the church of St Peter and Paul at Blockley, in Gloucestershire, which held the burial right to the inhabitants of the hamlets Stretton-on-Fosse in Warwickshire, where there was a chapel which became a rectory in the 12th century, and Aston Magna, where there was a chapel which was merely a chantry. All 'tithes' and 'mortuaries', however, came to the parish church of Blockley, to which church the people of Stretton and Aston were committed to carry their deceased for burial. The corpse road from Aston to Blockley churchyard is over two miles (3 km) long and crosses three small streams en route. The corpse road from Stretton to Blockley runs for some four miles (6 km) and crosses two streams.

The essence of deep-rooted spirit lore is that supposed spirits of one kind or another spirits of the dead, phantasms of the living, wraiths, or nature entities like fairies move through the physical landscape along special routes. In their ideal, pristine form, at least, such routes are conceived of as being straight, having something in common with ley lines. By the same token, convoluted or non-linear features hinder spirit movement i.e labyrinths and mazes.

Spirits or ghosts were said to fly along on a direct course close to the ground, so a straight line connecting two places was kept clear of fences, walls, and buildings to avoid obstructing the flitting spectres. The paths would run in a straight line over mountains and valleys and through marshes. In towns, they would pass the houses closely or go right through them. The paths end or originate at a cemetery; therefore, such a path or road was believed to have the same characteristics as a cemetery, where spirits of the deceased thrive.

The Corpse roads or ways were left unploughed and it was considered very bad luck if for any reason a different route had to be taken.

Corpse candles and other related phenomena

A Corpse candle or light is a flame or ball of light that is seen to travel just above the ground on the route from the cemetery to the dying person's house and back again. A Corpse Fire is very similar as the name comes from lights appearing specifically within graveyards where it was believed the lights were an omen of death or coming tragedy and would mark the route of a future funeral, from the victim's house to the graveyard.

Among European rural people, especially in Gaelic and Slavic folk cultures, the Will-o'-the-wisps are held to be mischievous spirits of the dead or other supernatural beings attempting to lead travellers astray (compare Puck). Sometimes they are believed to be the spirits of unbaptized or stillborn children, flitting between heaven and hell. Other names are Jack O' Lantern, or Joan of the Wad, Jenny Burn-tail, Kitty wi' the Whisp, or Spunkie.

Anybody seeing this phenomena might merely have been seeing, without knowing, a luminescing Barn Owl, at least in some instances. As strange as it may seem, much anecdotal evidence supports the fact that Barn Owls have a luminescence which may be due to fungal bioluminescence (Honey fungus) or some other cause.

Now it is that time of night, That the graves all gaping wide, Every one lets forth his sprite, In the church-way paths to glide.

Puck suggests a secret history of these routes, for unsurprisingly they attracted long extant folk lore, running not only through the physical countryside but also through the invisible geography, the 'mental terrain', of pre-industrial country-folk. Shakespeare's prose leaves little doubt that the physical corpse roads came to be perceived as being spirit routes, taking on qualities which lingered in the folklore of his age and which he incorporated into his play knowing that it would be a familiar concept.

The spirit roads, such as the church-ways, were always conceived of as being straight, but the physical corpse roads of the United Kingdom vary as much as any other path. Corpses were conveyed along defined corpse roads to avoid their spirits returning to haunt the living. It was a widespread custom, for example, that the feet of the corpse be kept pointing away from the family home on its journey to the cemetery.

Other minor ritualistic means of preventing the return of the dead person included ensuring that the route the corpse took to burial would take it over bridges or stepping stones across running water which spirits could not cross, stiles, and various other 'liminal' (betwixt and between) locations, all of which had reputations for preventing or hindering the free passage of spirits. The living took pains to prevent the dead from wandering the land as lost souls or animated corpses, for the belief in revenants (ghosts) was widespread in medi?val Europe.

People using the corpse roads assumed that they could be passages for ghosts. The ancient spirit folklore that attached itself to the medieval and later corpse roads also may have informed certain prehistoric features. In Britain, for instance, Neolithic earthen avenues called cursuses link burial mounds: these features can run for considerable distances, even miles, and are largely straight, or straight in segments, connecting funerary sites. The purpose of these avenues is imperfectly understood, but some kind of spirit-way function may be one reasonable explanation. Similarly, some Neolithic and Bronze Age graves, especially in France and Britain, are associated with stone rows, like those at Merrivale on Dartmoor, with intriguing blocking stones at their ends.

Homer Sykes in 'Mysterious Britain' (Weidenfeld & Nicolson, 1993) says that the 'holed' Cornish 'Tolvan' stone was used to block a now lost ancient burial chamber, and suggests that the hole allowed a way in for funeral purposes and a passage out for the spirits of the dead.

Associated legends and beliefs

A Devon legend tells of a funeral procession heading across Dartmoor on its way to Widecombe and the burial ground, carrying a particularly unpopular and evil old man. They reach the coffin stone and place the coffin on it while they rest. A beam of light strikes the coffin, reducing it and its contents to ashes and splitting the coffin stone. The party believes that God did not wish to have such an evil man buried in a cemetery.

Some country-folk claim that if a dead body is carried across a field it will thereafter fail to produce good crop yields. Throughout the United Kingdom and Europe it still believed that touching a corpse in the coffin will allow the departed spirit to go in peace to its rest, and bring good luck to the living.

An old woman at Fryup in Yorkshire was well known locally for keeping the Marks een watch (24 April), as she lived alongside a corpse road known as the Old Hell Road. In this 'watch', typically a village seer would hold a vigil between 11 pm and 1 am on St. Mark's Day, in order to look for the wraiths of those who would die in the following year.

Phantom lights are sometimes seen on the Scottish cemetery-island of Mun in Loch Leven and traditionally such lights were thought to be omens of impending death; the soul also was thought to depart the body in the form of a flame or light.

In Ireland, the fear gortach ("hungry grass"/"violent hunger") is said to grow at a place where an unenclosed corpse was laid on its way to burial. This is thought to be a permanent effect and anyone who stands on such grass is said to develop insatiable hunger. One such place is in Ballinamore and was so notorious that the woman of the nearby house kept a supply of food on hand for victims.

The existence of specific coffin stones, crosses or lych gates on church-ways, suggests that these may have been specially positioned and sanctified so as to allow the coffin to be placed there temporarily without the chance of the ground becoming in some way tainted or the spirit given an opportunity to escape and haunt its place of death.

Gerald of Wales (Giraldus Cambrensis) in the 13th-century relates the strange story of a marble footbridge leading from the church over the Alan rivulet in Saint Davids. The marble stone was called 'Llechllafar' (the talking stone) because it once spoke when a corpse was carried over it to the cemetery for internment. The effort of speech had caused it to break, despite its size of ten feet in length, six in breadth and one in thickness. This bridge was worn smooth due to its age and the thousands of people who had walked over it, however the superstition was so widely held that corpses were no longer carried over it. This ancient bridge was replaced in the 16th century and its present location is not known.

Another legend is that Merlin had prophesied the death on Llechllafar of an English King, conqueror of Ireland, who had been injured by a man with a red hand. King Henry II went on pilgrimage to Saint David's after coming from Ireland, heard of the prophesy and crossed Llechllafar without ill effect. He boasted that Merlin was a liar, to which a bystander replied that the King would not conquer Ireland and was therefore not the king of the prophesy. This turned out to be true, for Henry never did conquer the whole of Ireland.

The villagers in Manaton in Devon used to carry coffins three times round the churchyard cross, much to the irritation of the vicar, who opposed the superstition. Upon being ignored, he had the cross destroyed.

The 'Lych way' is a track lying to the south-west of Devil's Tor on Dartmoor. The dead from remote moorland homestesds were taken along this track to Lydford church for burial. Many reports have been made of monks in white and phantom funeral processions seen walking along this path.

Childe's Tomb on Dartmoor is the site of the death of Childe who was caught in a snowstorm, killed and disembowelled his horse and climbed inside fro sheleter, but still froze to death. He left a message to say that the first person to bury him would get his lands at Plymstock. The greedy monks of Tavistock buried him and claimed the lands. The ghosts of monks carrying a bier have been seen at Childe's tomb.

Crossroads

Places where tracks intersect are considered dangerous and are believed occupied by special spirit-guardians because they are places of transition where the world and the underworld intersect. The Celtic god Lugh indicated the right road at such places and was a guide to the traveler's footsteps. The god of the dead was the divinity of the crossroad and later Christian crosses were erected at such places.

Crossroads divination was conducted in Britain and other parts of Europe, and is associated with the belief that the Devil could be made to manifest at such intersections. Crossroads lore also includes the idea that spirits of the dead could be bound (immobilized or rendered powerless) at crossroads, specifically suicides and hanged criminals, but also witches, outlaws and gypsies. The belief was that since straight routes could facilitate the movement of spirits, so contrary features like crossroads and stone or turf labyrinths could hinder it. An example of a crossroad execution-ground was the famous Tyburn, London, which stood on the spot where the Roman road to Edgware crossed the Roman road heading west out of London.

This was part of a broader fear of spirits that might flit into dwellings. Witch bottles were common throughout Europe bottles or glass spheres containing a mass of threads, often with charms entangled in them. Its purpose was to draw in and trap evil and negative energy directed at its owner. Folk magic contends that the witch bottle protects against evil spirits and magical attack, and counteracts spells cast by witches, also forestalling the passage into habitations of witches flying about at night. A Witchball was much the same, however a more light-hearted belief was that the witch saw her distorted face in the curved glass and was frightened away. The term witch ball is probably a corruption of watch ball because it was used as a guard of evil spirits.

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