A
viaduct is a
bridgeA bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
composed of several small spans. The term
viaduct is derived from the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
via for road and
ducere to lead something. However, the
Ancient RomansAncient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
did not use that term per se; it is a modern derivation from an analogy with
aqueductAn aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....
. Like the
Roman aqueductThe Romans constructed numerous aqueducts to serve any large city in their empire, as well as many small towns and industrial sites. The city of Rome had the largest concentration of aqueducts, with water being supplied by eleven aqueducts constructed over a period of about 500 years...
s, many early viaducts comprised a series of arches of roughly equal length. Viaducts may span land or water or both.
The longest viaduct in
antiquityAncient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...
may have been the
Pont SermeThe Pont Serme or Pons Selinus, later called the Pons Septimus, was a Roman bridge of the Via Domitia in Hérault, southern France. The approximately 1500 m long viaduct crossed the wide marshes of the Orb River and the Etang de Capestang west of Béziers, surpassing in terms of length even the...
which crossed wide marshes in southern France. Viaducts are commonly used in many cities which are railroad centers, such as
ChicagoChicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, Atlanta,
BirminghamBirmingham is the largest city in Alabama. The city is the county seat of Jefferson County. According to the 2010 United States Census, Birmingham had a population of 212,237. The Birmingham-Hoover Metropolitan Area, in estimate by the U.S...
,
LondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, and
ManchesterManchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
. These viaducts cross the large railroad yards that are needed for freight trains there, and also cross the multi-track railroad lines that are needed for heavy railroad traffic. These viaducts keep
highwayA highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...
and city street traffic from having to be continually interrupted by the
trainA train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...
traffic. Likewise, some viaducts carry railroads over large valleys, or they carry railroads over cities with lots of cross-streets and avenues. The example of Viaduct on Expressways are Alabang Viaduct in
South Luzon ExpresswayThe South Luzon Expressway ', which is formerly called the South Superhighway ', and officially known as Radial Road 3 or R-3, is a network of three expressways that connects Metro Manila to the provinces of the CALABARZON region in the Philippines...
in
Muntinlupa CityThe City of Muntinlupa is the southernmost city in Philippine National Capital Region. It is bordered on the north by Taguig City; to the northwest by Parañaque City; by Las Piñas City to the west; to the southwest by the city of Bacoor, Cavite; by the city of San Pedro, Laguna; and by Laguna de...
,
PhilippinesThe Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
that crosses Alabang-Zapote Road in Barangay Alabang the viaduct reaches until Filinvest Interchange. In the north the Pulilan-Apalit Viaduct known as Candaba viaduct in
North Luzon ExpresswayThe North Luzon Expressway , and which is formerly called the North Diversion Road, and officially known as Radial Road 8 is a 4 to 8-lane limited-access toll expressway that connects Metro Manila to the provinces of the Central Luzon region in the Philippines...
in
PhilippinesThe Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
is raised over the Candaba swamp from
Pulilan, BulacanPulilan is a 1st class urban municipality in the province of Bulacan, Philippines. According to the latest census, it has a population of 85,008 inhabitants in 13,948 households...
until it reaches
Apalit, PampangaApalit is a Philippine municipality in the province of Pampanga, Philippines. It is situated in the Luzon Island. According to the latest census, it has a population of 97,296 inhabitants in 15,072 households....
. This keeps the highway open to traffic, even when the swamp gets flooded during the rainy season. It has a view of Mt. Arayat, which is the lone mountain in Central Plain of Luzon.
Many viaducts over land connect points of similar height in a landscape, usually by bridging a river
valleyIn geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
or other eroded opening in an otherwise flat area. Often such valleys had roads descending either side (with a small bridge over the river, where necessary) that become inadequate for the traffic load, necessitating a viaduct for "through" traffic. Such bridges also lend themselves for use by
railRail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
traffic, which requires straighter and flatter routes. Some viaducts have more than one deck, such that one deck has vehicular traffic and another deck having rail traffic. One example of this is the
Prince Edward ViaductThe Prince Edward Viaduct System, commonly referred to as the Bloor Viaduct or the viaduct, is the name of a truss arch bridge system in Toronto, Ontario, Canada that connects Bloor Street East, on the west side of the system, with Danforth Avenue on the east...
in
TorontoToronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
,
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, that carries motor traffic on the top deck as
Bloor StreetBloor Street is a major east–west residential and commercial thoroughfare in Toronto, in the Canadian province of Ontario. Bloor Street runs from the Prince Edward Viaduct westward into Mississauga, where it ends at Central Parkway. East of the viaduct, Danforth Avenue continues along the same...
, and metro as the Bloor-Danforth
subway lineThe Toronto subway and RT is a rapid transit system in Toronto, Ontario, Canada, consisting of both underground and elevated railway lines, operated by the Toronto Transit Commission . It was Canada's first completed subway system, with the first line being built under Yonge Street, which opened in...
on the lower deck, over the steep Don River
valleyThe Toronto ravine system is one of the most distinctive features of the geography of Toronto, Ontario, Canada. It is a network of deep ravines that form a large urban forest that runs throughout much of the city...
. Others were built to span settled areas and crossed over roads beneath - the reason for many viaducts in London.
Viaducts over water are often combined with other types of bridges or tunnels to cross navigable waters. The viaduct sections, while less expensive to design and build than tunnels or bridges with larger spans, typically lack sufficient horizontal and vertical clearance for large ships. See the
Chesapeake Bay Bridge-TunnelThe Chesapeake Bay Bridge-Tunnel is a long fixed link crossing the mouth of the Chesapeake Bay and connecting the Delmarva Peninsula's Eastern Shore of Virginia with Virginia Beach and the metropolitan area of Hampton Roads, Virginia...
.
The
Millau ViaductThe Millau Viaduct is a cable-stayed road-bridge that spans the valley of the river Tarn near Millau in southern France. Designed by the British architect Norman Foster and French structural engineer Michel Virlogeux, it is the tallest bridge in the world, with one mast's summit at . It is the...
is a cable-stayed road-bridge that spans the valley of the River Tarn near
MillauMillau is a commune in the Aveyron department in southern France. It is located at the confluence of the Tarn and Dourbie rivers.-History:...
in southern France. Designed by the French bridge engineer
Michel VirlogeuxDr. Michel Virlogeux is a French structural engineer and bridge specialist.-Career:Michel Virlogeux graduated from the École Polytechnique in 1967 and from the École Nationale des Ponts et Chaussées in 1970...
, in collaboration with architect Norman Robert Foster, it is the tallest vehicular bridge in the world, with one pier's summit at 343 metres (1,125 ft)—slightly taller than the
Eiffel TowerThe Eiffel Tower is a puddle iron lattice tower located on the Champ de Mars in Paris. Built in 1889, it has become both a global icon of France and one of the most recognizable structures in the world...
and only 38 m (125 ft) shorter than the
Empire State BuildingThe Empire State Building is a 102-story landmark skyscraper and American cultural icon in New York City at the intersection of Fifth Avenue and West 34th Street. It has a roof height of 1,250 feet , and with its antenna spire included, it stands a total of 1,454 ft high. Its name is derived...
. It was formally dedicated on 14 December 2004 and opened to traffic two days later. The viaduct
Danyang–Kunshan Grand BridgeThe Danyang–Kunshan Grand Bridge is the world's longest bridge. It is a long viaduct on the Beijing–Shanghai High-Speed Railway.-Bridge:The bridge is located between Shanghai and Nanjing in East China’s Jiangsu province. It includes a long section over water that crosses Yangcheng Lake in Suzhou....
in China is the longest bridge in the world according to
Guinness World RecordsGuinness World Records, known until 2000 as The Guinness Book of Records , is a reference book published annually, containing a collection of world records, both human achievements and the extremes of the natural world...
.
In
Romance languagesThe Romance languages are a branch of the Indo-European language family, more precisely of the Italic languages subfamily, comprising all the languages that descend from Vulgar Latin, the language of ancient Rome...
, the word
viaduct refers to a bridge which spans only land. A bridge spanning water is called
pontePonte, a word meaning bridge in Italian, Portuguese and Galician languages, may refer to:-Italy:Municipalities*Ponte , in the Province of Benevento*Ponte Buggianese, in the Province of Pistoia*Ponte dell'Olio, in the Province of Piacenza...
.
Past and future
Elevated expressways were built in rich cities such as
BostonBoston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...
(
Central ArteryThe John F. Fitzgerald Expressway, known locally as the Central Artery, is a section of freeway in downtown Boston, Massachusetts, designated as Interstate 93, U.S. Route 1 and Route 3. It was initially constructed in the 1950s as a partly elevated and partly tunneled divided highway...
),
SeoulSeoul , officially the Seoul Special City, is the capital and largest metropolis of South Korea. A megacity with a population of over 10 million, it is the largest city proper in the OECD developed world...
,
Tokyo, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
,
TorontoToronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
(
Gardiner ExpresswayThe Frederick G. Gardiner Expressway, colloquially referred to as "the Gardiner", is a municipal expressway in the Canadian province of Ontario, connecting downtown Toronto with its western suburbs...
). But some were demolished because they were ugly and divided the city. However in developing nations such as
ThailandThailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
,
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
(
Delhi-Gurgaon ExpresswayDelhi-Gurgaon Expressway is a long access-controlled toll expressway connecting Delhi, the national capital of India, and Gurgaon, an important satellite city of Haryana....
),
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
,
BangladeshBangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
,
PakistanPakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
, elevated expressways have been built and more are under construction to improve traffic flow, particularly as a workaround of land shortage when built atop surface roads.