Main Page | See live article | Alphabetical index

Road

A road is a strip of land connecting two or more destinations.

Table of contents
1 Word, history, funding
2 Driving on the right or on the left
3 Design
4 Construction
5 Causeway
6 See also
7 External links

Word, history, funding

In original usage, a "road" was simply fit for riding ("road" is cognate with "ride", e.g.: ships ride at anchor in roads). The word "street" was kept for roads that had been prepared to ease travel in some way (thus, many "Roman Roads" have the word "street" in their names whose origin is the Latin strata, given before the usage changed).

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 wheel tracks, and it is uncertain where "road" begins and trail ends. Roads are a prerequisite for road transport of goods on wheeled vehicles.

Many historical examples exist of road and road-building. Some of the most famous are the Roman roads and the Incan courier roads. 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 - provided only that the rivers were navigable in the right places (but, of course, availability of water transport also influenced settlement patterns). During the industrial revolution, a development of the road was made: the railway. Today, roads are almost exclusively built to enable travel by car and other wheeled vehicles, and in most countries road transport is the most utilized way to move goods.

Roads situated in cities are often, but not always, called streets or alleys; this reflects the historical fact that when they were first named there were more likely to be unmade roads in open country and paved roads in urban areas. This leads to roads being sometimes named for their destination or direction, while streets may be named for their location.

Road building and maintenance is one of the few areas of economic activity (compare military spending) that remain 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 are funded by tollss.

Driving on the right or on the left

Traffic drives, depending on the country, either on the right or on the left side of the road. Driving on the left occurs in the UK, most of her former colonies, Japan and some other counties, covering about a third of the world's population. Sweden changed from left to right in 1967, depite a referendum in 1955 where 83% voted to stay on the left. There is some evidence of cart tracks from a quarry in Blunsdon Ridge near Swindon which suggests that Romans drove on the left, and until the 18th century, this was probably the most common choice in Europe. However driving on the right was more common in France; this was imposed by Napoleon Bonaparte on the countries he occupied, and thus it became the practice in their colonies. (See also Road transport and Rules of the road and the external link Which side of the road do they drive on?.)

In countries where traffic drives on the right:

and conversely.

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

Roads are built by removing vegetation. 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 or concrete. The main purpose of the wearing course is to prevent moisture from entering the road.

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 stick out a bit, but you can drive over them.

Road signss are often also made retroreflective. For greater visibility of road signs at daytime, sometimes fluorescence is applied to get very bright colors.

Causeway

A causeway is an elevated road, not on a bridge but on elevated ground, often through a body of water or through wet land. It may also serve as a dyke that keeps two bodies of water apart, e.g. with a different water level on both sides, and/or with salt water on one side and fresh water on the other side (this may also be the primary purpose, the road being a side benefit).

Examples are those that connect Marken, Singapore and Venice to the mainland, and the Afsluitdijk, Brouwersdam, Markerwaarddijk.

See also

External links


Road is a 2002 Hindi movie by Ram Gopal Varma starring Vivek Oberoi and Manoj Bajpai.