Roads and Highways
Webpages concerning "Roads and Highways"
|
The contents has been generating using technology developed by scientec.
Wikipedia-Article "Roads"
A road is a strip of land, smoothed, paved, or otherwise prepared to allow easy travel, connecting two or more destinations. Some roads are streets, chiefly in urban areas.
In the context of railways (railroads in American English), a road is a single track, which may be part of a multi-track system or may be an isolated line. In the context of sea transport, a road is an anchorage.
Contents |
Usage and etymology
In original usage, a "road" was simply any pathway fit for riding ("road" is cognate with "ride", e.g.: ships ride at anchor in roads). 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 street name.
However, modern usage does not usually make this distinction and it is only important since place names often hold the earlier usage in them; these days, roads are also prepared in some way. This includes, at the least, the removal of trees and smoothing of the ground. In some dialects, lower grade roads are called trails and tracks and it is uncertain where "road" begins and trail ends. Roads are a prerequisite for road transport of goods on wheeled vehicles.
The word “road” emphasizes its function of transportation along its length, while a “street” may be considered to have activity and commerce taking place on it (see street life).
History
The first pathways were the trails made by migrating animals. By about 10,000 BC, these rough pathways were used by human hunter nomads following these herds.
Street paving has been found from the first human settlements around 4,000 BC.
The oldest engineered road discovered is the Sweet Track causeway in England, dating from the 3800 BC.
The Ancient Egyptians constructed a stone paved road to help move materials for the building of the Great Pyramid in about 3000 BC.
The ancient Chinese constructed an extensive system of roads, some paved, from about 1100 BC onwards. By 20 AD, the Chinese road network extended over 40,000km.
The Incas built fine highways for couriers through the Andes, and the Mayans built an extensive network of paved roads in Mexico before the European discovery of the New World.
In ancient times, transport by river was far easier and faster than travel 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 is the horse-drawn boat in which the horse follows a cleared path along the river bank.
From about 300 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, in support of its military campaigns.
Road construction and maintenance in Britain was traditionally done on a local parish basis. The poor and variable state of the roads that resulted lead to the first of the 'Turnpike Trusts' around 1706. These were formed to build good roads and collect tolls from passing vehicles. Eventually there were approximately 1,100 Trusts in Britain and some 38,000 km of engineered roads.
Engineered roads in the age of horse drawn transport aimed for a maximum gradient of 1 in 30 on a macadamized surface since this was the steepest a horse could exert to pull a load up hill which it could manage easily on the flat. Notable road engineers from this period are Pierre Marie Jérôme Trésaguet (1716-1796) in France and John Loudon McAdam (1756-1836) in England.
During the industrial revolution,the railway developed as a solution to the problem of rutting of the road surface by heavy carts. Instead of trying to build a strong surface across the whole road the cart was constrained to run either on rails or grooves which could be made of much stronger , wear resistant material.
Today, roads are almost exclusively built to enable travel by car and other wheeled vehicles. In most countries, road transport is the most utilized way to move goods. Also, in most developed countries, roads are formally divided into lanes to ensure the safe and smooth movement of traffic.
Funding
Road building and maintenance is an area of economic activity (compare military spending) 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.
Driving on the right or the left
Traffic drives on the right or on the left side of the road depending on the country. See Rules of the road. In countries where traffic drives on the right, traffic signs are mostly on the right side of the road, roundabouts (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 drives on the left, the reverse is true.
Traffic flow and road design in both cases are each other's mirror image.
Design
Road design consists of two important technical aspects:
Besides these two technical sides of the design, environmental issues, planning issues and juridical issues are important.
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. Removal of earth and rock by digging or blasting, construction of bridges and tunnels, and removal of vegetation (this may involve deforestation) are often needed. A variety of road building equipment is employed in road building.
The soil is tested to see if it will support weight and if not, a layer of soil is removed and replaced. The soil is compacted to form what is known as a "base course". On top of the base course is placed a wearing course which consists of asphalt concrete or concrete. While the main purpose of the wearing course is to prevent moisture from entering the road, for safety reasons this wearing course must also be constructed to ensure adequate grip (and skid resistance) with vehicles.
Modern roads, and indeed many ancient ones, such as those built by the Romans, feature a convex lateral surface known as camber. This is designed to allow water to drain away from the road to its edges. Water is then carried away by gutters to drains placed at intervals. Some roads don't have gutters and water simply drains away to a naturally porous verge, or into ditches. Modern roads that carry motor traffic also employ camber in curves to aid traffic stability by allowing them to "bank into" the bend to some extent.
On the side of the road there may be retroreflectors on pegs, rocks or crash barriers, white toward the direction of the traffic on that side of the road, and red toward the other direction. In the road surface there may be cat's eyes: retroreflectors that protrude slightly, but which can be driven over without damage.
Road signs are often also made retroreflective or even illuminated in rare circumstances. For greater visibility of road signs at daytime, sometimes fluorescence is applied to get very bright colors.
Maintenance
Like all outdoor structures, roads deteriorate over time. They may develop cracks or potholes, or be washed away altogether by floods. Cracks can be filled with various sealants and potholes can be filled with fresh asphalt, but eventually a whole new surface is needed. Lack of maintenance speeds up the deterioration, especially in frost-prone areas, as water enters the cracks, and freezes under the road. The resulting ice has a bigger volume than the water, which causing a localized rising and falling (when the ice melts again) of the wearing course which can severely damage the road.
Most European countries have strict standards for road construction that ensure that most roads should be able to go 30 years or longer between major resurfacings. The United States and many other countries have less stringent standards under which most roads last only 20 to 25 years. However, even those countries with stricter standards suffer from increasing levels of truck traffic, which is mainly responsible for road damage (see below).
On any road, the load per vehicle axle passing over it is mainly responsible for the amount of wear. According to a series of experiments carried out in the late 1950s, called the AASHO Road Test, it was empirically determined that the effective wear done to the road is roughly proportional to the 4th power of vehicle weight. As a result, truck traffic almost always is the exclusive 'real' cause of road damage.
In an example, a hypothetical car weighs half a ton per axle. A 6-axle, 38-ton truck also travelling on the same road weighs in at over 6 tons per axle. The truck causes 20,736 times the wear of the car (12 times the car's axle load, with a power of 4, yielding 12^4 = 20,736). Actual trucks can have even higher axle loads, though there is a wide variation in the configuration of trucks, with some having larger, wider tyres, or multiple tyres per axle, which will cause the exact figures to vary. While such figures sound dramatic, it should be realised that a single car causes almost no wear at all, so 20,000 times this figure still may not be very high. The wear is only measurable over an extended period.
Terminology
- arterial road
- asphalt
- autobahn
- autoroute
- autostrasse
- bitumen
- byway
- bypass
- bottleneck
- boulevard
- cat's eye
- chicane
- concrete
- corduroy road
- corniche
- cul-de-sac
- curb extension
- dirt road
- divided highway
- expressway
- farm to market
- freeway
- gravel road
- guard rail
- green lane
- hard shoulder
- highway
- Interchange
- Intersection
- Interstate
- lane
- median
- mountain pass
- milestone
- motorway
- off-ramp
- on-ramp
- Parkway
- pavement
- pavement markings
- pedestrian crossing
- performance
- plank road
- private highway
- private road
- public road
- public space
- ranch road
- range road
- ridge road
- road number
- road safety
- road junction
- roadworks
- roundabout intersection
- rural route
- state highway
- street
- super-highway
- toll road
- traffic calming
- traffic circle
- traffic light
- traffic sign
- US highway
- winter road
See also
References
- Lay MG, Ways of the world. Rutgers University Press, New Brunswick, New Jersey, (1992). ISBN 0813517583 .
External links
Wikipedia-Article "Highways"
- For other uses, see Highway (disambiguation).
A highway is a major road within a city, or linking several cities together. It includes roads known as interstate highway, freeway, motorway and autobahn, where a full description varies by country. Generally, a highway is a road which has multiple lanes of traffic in each direction, often with a physical division (median) between opposing traffic, and separate access ramps to and from the highway which are more widely separated than connections on a standard road and are often grade-separated. A highway may prohibit access by pedestrians and limit what vehicles may travel on it.
Historically, a highway was any major road travelling a long distance outside of a city. Early roads between cities would sometimes suffer from highwaymen who would rob people travelling the route.
In the 20th century, however, the word generally came to be used only for high-speed, often specially-designed automobile routes. On 10 September 1913 the first paved coast-to-coast highway opened in the US.
Highways usually have a higher speed limit than other roads because they have additional lanes and are designed for driving at a higher speed. In remote areas, a highway may have rest areas where motorists may stop and relax before resuming a long drive.
By convention, the lane nearest the median on a multi-lane highway is called the passing lane.
The United States has a vast network of national highways (Interstate highways) linking the different U.S. states together, as does Australia albeit on a much smaller scale and mostly concentrated on the southeast coastline. Some highways, like the Pan-American Highway or the European routes, bridge multiple countries. With the latter a single road may have several national designations in addition to the European one.
Probably the most famous highway in the United States is Route 66, as immortalised in the song "(Get Your Kicks On) Route 66", while if one follows Australia's Highway 1 the driver can travel from state capital to state capital, almost the entire way around the whole country.
The longest single national highway in the world is the Trans Canada Highway, which runs from Victoria, British Columbia, on the Pacific Coast, through ten provinces to the Atlantic Coast, at St. John's, Newfoundland.
Contents |
Nomenclature
The terms used for various types of highways such as freeway, expressway, motorway and autobahn, vary between countries or even regions within a country. In some places a highway is a specific type of major road that is distinct from freeway or expressway; in other places the terms may overlap. In law highway may mean any public road or canal. However, in some countries, the term highway is not generally used at all.
Australia
In Australia, a highway is a distinct type of road from freeways and motorways. The word highway is generally used to mean major roads connecting large cities, towns and different parts of metropolitan areas. Metropolitan highways often have traffic lights at intersections, and rural highways usually have only one lane in each direction. The words freeway or motorway are generally reserved for the most arterial routes, almost always with no traffic light intersections and usually significantly straightened and widened. The term motorway is used in some Australian cities to refer to freeways that have been allocated a metropolitan route number, and in Sydney, a motorway has a toll, whereas a freeway is free of charge. It is now possible to travel from Melbourne to Sydney without having to stop at a traffic light. Roads may be part-highway and part-freeway until they are fully upgraded.
New Zealand
In New Zealand, a motorway runs through urban areas and an expressway runs through rural areas. Both motorways and expressways generally have no access to adjacent properties and no facility for pedestrians or cyclists. New Zealand's main routes are designated state highways. State Highway 1 is the only route to run through both the North and South Islands, and runs (in order north-south) from Cape Reinga to Wellington in the North Island, and from Picton to Bluff in the South Island. State Highways 2-5 are main routes in the North Island, State Highways 6-9 in the South Island, and state highways numbered from 10 onwards are generally found in numerical order from north to south. State highways usually incorporate different types of roads, for example, State Highway 1 from Auckland to Hamilton incorporates the Northern and Southern Motorways in the Auckland area, the Waikato Expressway, and a rural road before passing through the streets of Hamilton. The term freeway is rarely used relating to New Zealand roads, and can only be considered an Americanism.
Brazil
In Brazil, highways (or expressway/freeway) are named "rodovia", and Brazilian highways are divided in two types: regional highways (generally of less importance and entirely inside of one state) and national highways (of major importance to the country). In Brazil, rodovia is the name given exclusively to roads connecting two or more cities with a sizable distance separating the extremes of the highway. Urban highways for commuting are uncommon in Brazil, and when they are present, they receive different names, depending of the region (Avenida, Marginal, Linha, Via, Eixo, etc). Very rarely names other than "rodovia" are used.
Regional highways are named YY-XXX, where YY is the abbreviation of the state where the highway is running in and XXX is a number (e.g. SP-280; where SP means that the highway is running entirely in the state of São Paulo).
National highways are named BR-XXX. National highways connects multiples states altogether, are of major importance to the national economy and/or connects Brazil to another country. The meaning of the numbers are:
- 001-100 - it means that the highway runs radially from Brasília. It is an exception to the cases below.
- 101-200 - it means that the highway runs in a south-north way.
- 201-300 - it means that the highway runs in a west-east way
- 301-400 - it means that the highway runs in a diagonal way (northwest-southeast, for example)
- 400-499 - another exception, they are less important highways and its function is to connect a city to an arterial highway nearby
Often Brazilian highways receives names (famous people, etc), but even though, they continue to have a YY/BR-XXX name (example: Rodovia Castelo Branco is also SP-280).
See List of Brazilian Highways
Canada
- In Canada, there is no national standard for nomenclature, although highway appears more popular in all areas except
- Ontario: highways are called expressway or 400-Series; 401 in Toronto is a freeway. The DVP (Don Valley)is a parkway. All provincial managed highways are called King's Highways. Highway 407 is a toll route.
- Quebec where highways are called autoroutes (borrowing the term from French).
- Nova Scotia numbers its freeways by the routes they parallel, for example, Highway 101 parallels Trunk 1.
- The Trans Canada Highway, the highway (mostly four lane, sometimes less, sometime more) that crosses the entire country (and entering all ten provinces), holds the record as the longest national highway in the world. The only portions of this road not considered to be of freeway status are in the British Columbia Rocky Mountains, Northern Ontario, and in Newfoundland.
China
"Highways" in China, more often than not, refer to China National Highways. The multi-lane, central-separation routes are instead called expressways.
In Mainland China, private companies reimbursed through tolls are the primary means of creating and financing the National Trunk Highway System.
There is actually no separate classification for expressway (which is the term more often used in the PRC). Most likely, they are lumped with first-grade guodaos (meaning National roads). Beneath guodaos in rank level are shengdaos (provincial roads) and xiandaos (pronounced hsien-daos or shien-daos, which equate to county-level roads). Some expressways are numbered with a leading zero (e.g. G030).
Freeway was used on a few expressways (such as the Jingshi Freeway) before expressway was chosen as a standarised term.
The Chinese name for expressways (or freeways, as they used to be called) is uniform; in pinyin, it is gao su gong lu, which literally means "high speed public road".
In the mainland of the PRC, highway does not refer to a freeway or expressway, but instead to a normal road equivalent to an "A"-level road in Britain, or a class-one non-expressway. This can cause some confusion, though.
Hong Kong
In Hong Kong, the type of high speed roads is referred to as expressway, but some are named as highways or roads ('Yuen Long Highway', 'Tolo Highway', 'Tsuen Wan Road', 'Tuen Mun Road', etc.). Some others are named corridors and bypasses.
India
Main article Indian highways
In India, 'Highway' refers to one of the many National Highways that run up to a total length of about 58000 kilometers. An expressway refers to any elevated road with grade-separated intersections.
Malaysia
The highest level of major roads in Malaysia, expressway (lebuhraya), has full access control, grade separated junctions, and mostly tolled. The expressways link the major state capitals in Peninsular Malaysia and major cities in Klang Valley.
Highway is lower level with limited access control, some at-grade junctions or roundabouts, and generally with 2 lanes in each separated direction. These are generally untolled and funded by the federal government, hence the first one is called Federal Highway linking Klang and Kuala Lumpur.
The trunk roads linking major cities and towns in the country are called federal trunk roads, and are generally 2 lanes single carriageway roads, in places with a third climbing lane for slow lorries.
South Africa
Colloquially, the terms "freeway," "highway," and "motorway" are used synonymously. There are very few references to the term "expressway" in South Africa. A freeway, highway or motorway refers to a divided dual carriageway with limited access/egress, with at least two lanes in either direction. A central island, usually either with drainage, foliage or high-impact barriers, provides a visible separation between carriageways in opposite directions. As with the UK and Australia, South Africans drive on the left-hand side of the road and all steering wheels are on the right-hand side of vehicles.
Freeways are designated with one of three labels: N (in reference to national roads), R (short for "route," in reference to provincial roads), and M (in reference to metropolitan roads). This has more to do with the location of a road and its function than anything else. In addition, "N" roads usually run the length of the country over long distances, "R" roads usually inter-connect cities and towns within a province, and "M" roads carry heavy traffic in metropolitan areas. Route markings also determine who paid for the road: "N" was paid for by national government, "R" by provincial government and "M" by local government. In recent years, some "R" roads have been re-designated as "N" roads, so that control and funding comes from the South African National Roads Agency.
Switzerland
The term Autobahn is used for normal expressways where there is a central physical structure separating two different directional carriageways. This is often translated into English as motorway.
In express routes where there is no central physical structure separating two different directional carriageways, but crossings are still motorway-like otherwise, and traffic lights are not present, the road is instead called an Autostrasse, translated into English as a motorroad. Autostrassen often have a lower speed limit than Autobahnen.
See also: Lists of Autobahns
United Kingdom and Ireland
In the United Kingdom and Republic of Ireland, unless a route is classified as a motorway, the term used may be main road, trunk road, 'N' road/'R' road (In Ireland), 'A' road/'B' road (In The UK), or, where appropriate, dual carriageway. In the law of England and Wales the term highway covers everything from a footpath (for foot passage only), to a bridleway (for foot, bicycle and equestrian use), to a byway open for all traffic (for all the aforementioned users, plus any motorised user), to unclassified county roads, classified roads, trunk roads, motorways and special roads. In British law, there is no definition of "road", and generally the most common usage refers to:
- "Carriageway",
- "Footpath",
- "Bridleway" or
- "Byway"
In England and Wales the public are said to have a "right of way" over a Highway. This means that, subject to statutory restrictions, the route must be kept clear to allow travel by anyone who wishes to it. At common law, it is forbidden to obstruct a highway or interfere with passage. However, many statutory provisions provide powers to do so (for instance to carry out road works). Rights of way exist both over roads maintained at the public expense (the majority of roads) and over some roads on private property. In this case, the owner must allow passage over the highway. A right of way may be created by custom (i.e. the road has been used for a long period of time) or under the relevant positions of the Highways Act 1980. A right of way may by only be extinguished or diverted by or under an Act of Parliament. For instance, under the Channel Tunnel Rail Link Act 1996 authority is given for the builder of the rail link to stop up certain highways mentioned in Schedule 3 of the act. The contrast to a Highway is a private road over which no right of way exists. Travel on a private road is subject to the consent of the owner of the land.
United States
In the U.S., the meaning of the term "highway" varies considerably from place to place and person to person. There are three basic meanings for "highway" used in the United States: a high-speed limited-access road like expressways and freeways, a main or important road that goes a long distance outside of a city, or any road at all.
The Interstate Highway system, which consists almost entirely of freeways, is familiar to most Americans, and this results in the word "highway" being sometimes used to describe any high-speed limited-access road, regardless of whether it is part of the Interstate Highway system. See freeway for information about the distinctions between freeways and expressways.
The U.S. Highways, which predate the Interstate Highways, are mainly not high-speed limited-access roads, but are distinguished from other roads by being mainly important routes that lead from one settled area to another, rather than roads confined to one city. The usage of the word "highway" to refer to the U.S. Highways and similar roads which are not part of the U.S. Highway system, reflects the older usage of the word "highway" that means a road that goes a long distance outside of a city.
Finally, further confusing the issue is the fact that, in some places, "highway" is legally just a synonym for "road" or "street", such as in California, where Cal. Motor Veh. Code § 360 states: "'Highway' is a way or place of whatever nature, publicly maintained and open to the use of the public for purposes of vehicular travel. Highway includes street."
Further information
For information on the history and local styles of highways around the world refer to
- Auto-Estrada (Portugal)
- Autopista (Spain)
- Autoroute (France)
- Autoroute (Quebec)
- Autobahn (Germany)
- Autostrada (Italy)
- Highways (India)
- Expressway (Mainland China)
- Expressway (Lebuhraya) (Malaysia)
- Freeway, Expressway, and Parkway (United States)
- Freeway (Canada)
- Motorway (United Kingdom)
- Motorway (Ireland)
- National Trunk Highway System (Mainland China)
- Rodovia (Brazil)
See also
- Bypass
- Countryside and Rights of Way Act 2000
- Highway Gothic - a font standard for highways in US and Canada.
- List of roads and highways
- Passing lane
- Ring road
- Road
- Road junction
- Road safety
- Toll road
External link
