A railroad or railway is a guided means of land transport, designed to be used by trains, both passengers and freight are transported on railways. It consists of two parallel rails, usually made of steel, and wooden or concrete sleepers or ties that hold the rails exactly at the proper distance from each other. see rail tracks

General

Rail transport is the most energy efficient means of mechanised transport known. The rails provide very smooth and hard surfaces on which the wheels of the train may roll with a minimum of friction. This is more comfortable and saves energy. Trains also have a small frontal area in relation to the load they are carrying, which cuts down on air resistance and thus energy usage. In all, a train needs 50-70% less energy to transport a given tonnage of freight (or given number of passengers), than by road. Furthermore, together with the sleepers the rails distribute the weight of the train evenly, allowing significantly greater loads per axle/wheel than in road transport.

The sleepers (called "ties" or "cross-ties" in North America) are embedded in ballast, such as crushed rock. Sometimes sleepers and ballast are replaced by concrete slabs, e.g. in tunnels.

Railways can be built with different distances between the two tracks, the distance between the two tracks is known as the Rail gauge.

Railways use signaling (usually colour lights) to prevent trains from colliding.

Railroads may or may not be electrified. If they are not, they can only be used by non-electric trains, mainly diesel trains. In many parts of the world large parts of the railroad network have been electrified. Electric trains do not have to carry their own fuel. They are cleaner and less noisy.

To be electrified, a means of supplying electricity to the train is needed, this may be done by overhead wires, or by a third rail system. The former is the most common method.

High speed rail, with speeds up to 350 kilometers per hour, are achieved by a specially built railroad and special trains.

For short, steep stretches funiculars or cable car railways and cog railways provide railway functionality.

In a broader sense, the term railroad includes monorail, rubber-tired metro and maglev, since the cars also run in a guided path.

Major cities often have metro and/or light rail/tram systems. For a tram on the road the terms streetcar track or tram track are used, rather than railroad or railway. A tram with its own right-of-way it is called a tramway.

Depending on how much traffic they carry, railways can be built with a varying number of tracks. Rail lines that carry little traffic are often built with a single track which is used by trains traveling in both directions; on rail lines like these, "passing loops" or "passing sidings", which consist of short stretches of double track, are provided at certain points along the line to allow trains to pass each other, and travel in different directions. Single-track lines are cheaper to build, but can only handle a limited amount of traffic.

On busier lines, two or more tracks are provided, one or more for each direction of travel. On very busy lines as many as eight tracks (four tracks in each direction) are used to handle large amounts of traffic.

With the advent of containerized freight in the 1960s, rail and ship transportation have become an integrated network that move bulk goods very efficiently with a very low labor cost. An example is that goods from east Asia that are bound for Europe will often be shipped across the Pacific and transferred to trains to cross North America and be transferred back to a ship for the Atlantic crossing.

History in brief

Early horse drawn wagonways operated in Europe, from around 1550 usually operating with crude wooden tracks.

The first steam locomotive to operate on tracks, built by Richard Trevithick was operated in 1804 In Wales, although it was not fianancially successful.

The first successful steam locomotives were built by George Stephenson, culminating in his famous Rocket locomotive.

The first succesful steam operated railway, was the Stockton and Darlington Railway in northern England in the 1820s, which was soon followed by the Liverpool and Manchester Railway proved the viabillity of rail transport.

Railways soon spread throughout England and through the world, and became the dominant means of land transport for nearly a century, until the invention of aircraft and automobiles, which prompted a gradual decline in railways.

Diesel and electric trains and locomotives replaced steam, in many countries, in the decades after World War II.

Many countries since the 1960s have adopted High-speed railways.

Terminology

To distinguish two directions on a given line sometimes one is called the up train and the other down train, which may for example mean from and toward the center or the big city.

In Britain and other commonwealth countries the term railway is used in preference to railroad.

• American English - railroad
• Commonwealth English - railway
• Romanian - cale feratã' (iron way)
• Danish - jernbane (iron way)
• Dutch - spoorweg (track road)
• Finnish - rautatie (iron road)
• French - chemin de fer (way of iron)
• German - die Eisenbahn (iron road)
• Greek - S?d???d??µ?? - Sidirodromos (iron road)
• Italian - ferrovia (iron way)
• Japanese - tetsudou (iron road)
• Korean - cheoldo (iron road)
• Spanish - ferrocarril (iron road)
• Swedish - järnväg (iron way)
• Russian - zheleznaya doroga (iron road)
• In Britain the term railway is often used to refer to the complete organisation of tracks, trains, stations, signaling, timetables and the organising companies which collectively make up a coordinated railway system, while permanent way or p/way refers to the tracks alone. See also British railway system.

Statistics

Of the 236 countries and dependencies, 143 have rail transport (including several with very little), of which ca. 90 with passenger services