This early German Autobahn uses a dual carriageway design.

A dual carriageway or divided highway is a road or highway in which the two directions of traffic are separated by a central barrier or strip of land, known as a central reservation or median. A German Autobahn in the late 1930s. ... A German Autobahn in the late 1930s. ... Autobahn (pronounced in IPA, plural Autobahnen) is the German word for a major high-speed road usually linking one or more cities and towns, similar to motorway or freeway in English-speaking countries. ... This page is related to transport; you may be looking for the 2002 Bollywood movie Road. ... A highway is a major road within a city, or linking several cities together. ... For central reservations (such as for hotels), see call center. ...

United Kingdom

In the U.K., although the term dual carriageway applies to any road with separated lanes, it is frequently used as a descriptive term for major routes built in this style. Such major dual carriageways usually have two lanes of traffic in each direction, with the lane nearest the centre being reserved for overtaking. Occasionally dual carriageways have only one lane in each direction, or more than two lanes each way (usually to permit easier overtaking of slower uphill traffic). Different speed limits apply on dual carriageway sections than apply on single carriageway sections of the same class of road, except in cities and built-up areas where the dual carriageway is more of a safety measure, often intended to prevent pedestrians from crossing a busy road. The United Kingdom of Great Britain and Northern Ireland is a country in western Europe, and member of the Commonwealth of Nations, the G8, the European Union, and NATO. Usually known simply as the United Kingdom, the UK, or (inaccurately) as Great Britain or Britain, the UK has four constituent... A highway is a major road within a city, or linking several cities together. ... A pedestrian at the intersection of Alinga Street and Northbourne Avenue, Canberra, Australia A pedestrian is a person travelling on foot, whether walking or running. ...

Turning right (that is, across the line of traffic heading in the opposite direction) is usually only permitted at specific locations. Often the driver will be required to turn left (away from the dual carriageway) in order to loop around to an access road that permits crossing the major road. Roundabouts on dual carriageways are relatively common, especially in cities or where the cost of a grade-separated junction would be prohibitive. A roundabout, rotary, or gyratory circus is a type of road junction (or traffic calming device) at which traffic streams circularly around a central island after first yielding to the circulating traffic. ...

A long-distance dual carriageway with grade-separated junctions and which meets other requirements may be upgraded to motorway standard, denoted as an (M) added after the road number (eg. "A1(M)"). A motorway (Ireland, New Zealand, the United Kingdom and some Commonwealth nations) is both a type of road and a classification. ...

The national speed limits on dual carriageways not in built-up areas are as follows. Local speed limits, where indicated by signs, take precedence over these. A speed limit is the maximum speed allowed by law by vehicles on a road. ...

A small variety of cars, the most popular kind of automobile. ... A tonne (also called metric ton) is a non-SI unit of mass, accepted for use with SI, defined as: 1 tonne = 103 kg (= 106 g). ... A motorcycle (or motorbike) is a two-wheeled vehicle powered by an engine. ... Caravans comprise land-based trading convoys, often utilising the camel as a beast of burden, and generally associated with crossing deserts in Asia or Africa. ... The Bus, established by Mayor Frank Fasi, is Honolulus only public transit system. ... This article discusses transportation vehicles. ...

United States

In the U.S. this type of road is called a divided highway and has a median strip between the traffic directions.

Junctions may be at-grade or grade-separated, and there may be gaps in the median strip to allow turning and crossing.

China

The best example of dual carriageways in mainland China can be seen on the China National Highways. On some routes, such as China National Highway 106, there is a central reservation. In this map of China, the light-coloured areas represent Mainland China, while yellow coloured area refers to Taiwan. ... The China National Highways are a series of trunk roads throughout all of China. ... Related: Transportation of Beijing Part of the WikiProject Transportation in China Categories: Stub | Peoples Republic of China roads and expressways ...

Switzerland

Swiss dual carriageways are referred to as Autostrasse. There may or may not be a central reservation. Signpost to an Autostrasse (this one leads to the A1L motorroad leading out of central Zürich). ...

History

A very early example (perhaps the first) of a dual carriageway was the Via Portuensis, built in the 1st century by the Roman emperor Claudius between Rome and its port Ostia at the mouth of the Tiber. (1st century BC - 1st century - 2nd century - other centuries) The 1st century was that century which lasted from 1 to 99. ... Emperor Claudius Tiberius Claudius Nero Caesar Drusus (August 1, 10 BC _ October 13, 54), originally known as Tiberius Claudius Drusus Nero Germanicus, was the fourth Roman Emperor of the Julio_Claudian dynasty, ruling from January 24th 41 to his death in 54. ... Location within Italy The Roman Colosseum Rome (Italian and Latin: Roma) is the capital city of Italy and of its Latium region. ... Ostia, an ancient town on the coast facing the Tyrrhenian Sea, in Latium, Italy, was the harbour of ancient Rome and perhaps its first colonia. ... Tiber River in Rome The River Tiber (Italian Tevere), the third longest river in Italy (disputed — see talk page) at 406 km (252 miles) after the Po and the Adige, flows through the Campagna and Rome in its course from Mount Fumaiolo to the Tyrrhenian Sea, which it reaches in...

See also

• Highway
• Freeway
• Motorway
• Autostrasse
• Expressway