A bridge is a structure built over obstacles such as rivers and valleys. It plays an important role in the rise of transportation, local and worldwide trade, as well as the spreading of knowledge.
One of the earliest and simplest types of bridges is stepping stones. The first human-made bridges with substantial spans were intentionally felled trees.
There were several innovations in bridge designs during the 18th century. The first book on building bridges was written by French engineer Hubert Gautier in 1716.
In the late 1770s, humans achieved a milestone in bridge technology with the development of the Iron Bridge in Shropshire, England. Between the 18th and 19th centuries, thousands of bridges were built in the United States and Canada, drawing inspiration from earlier designs in Switzerland and Germany.
Today’s bridges strongly vary in terms of their appearance, construction materials, carrying capacity, and movable sections. They all can be categorized in several ways. Below, we have listed the most popular types of bridges in the world, each serving different purposes.
Did you know?
The world’s longest bridge, the Danyang–Kunshan Grand, stretches an astonishing 102.4 miles, connecting two Chinese cities over land and water.
Table of Contents
23. Clapper Bridge
Postbridge dating from the 13th century
Span range: Short
A clapper bridge is an ancient type of bridge where large, flat stone slabs, often made of materials like schist or granite, rest on piles of stones. Most of these bridges were constructed during medieval times to provide a pathway across a river.
A notable example is the Postbridge, located beside the East Dart River in Devon, England. The slabs of this bridge are over 6 feet (2 m) wide and more than 13 feet (4 m) long, each weighing more than 8 tons. Dating back to the 13th century, it was built to facilitate the crossing of packhorses carrying tin to the stannary town of Tavistock.
22. Natural Bridge
A 92-foot tall natural arch, Azure Window
Span range: Short
Many naturally created arch formations resemble a bridge. Those bridges could have been formed from river flow, wind erosion, or the collapse of lava tubes.
Azure Window, for example, on the island of Gozo, was created by the collapse of a sea case, probably during the 19th century. Another well-known example is the Natural Bridge in Virginia, a geological formation featuring a 215-foot tall natural arch with a 90-foot span.
21. Beam Bridge
A footbridge using beams over a stream
Span range: Short
A Beam (or stringer) bridge represents the simplest structural design for spans supported by a pier at each end. To build this type of bridge, you only require a beam, which is a rigid horizontal structure, and two supports on each end. These supports bear the downward weight of the structure and the traffic moving across it.
Unlike suspension and truss bridges, beam bridges are suitable for relatively short distances. Because support is provided by piers alone, the structure becomes weaker as the piers are spaced farther apart. As a result, these bridges typically do not span more than 250 feet.
20. Truss Bridge
Through truss General Hertzog Bridge | Wikimedia
Span range: Short to medium
Instead of relying on a single beam to bear all the forces, a series of beams and trusses are used in the construction of the Truss Bridge. A truss, which is a triangular frame, is employed to spread the tension and compression forces along the bridge.
There are various ways to construct a truss bridge, all aiming to distribute the forces and prevent the bridge from collapsing. By arranging strong beams in a triangle, a truss provides a stable form capable of supporting heavy external loads over a significant span.
A view of a metal truss bridge over the South Platte River at 19th (Nineteenth) Street in Denver, Colorado. A small wood shed with a pyramidal roof is in the foreground. (1930-1940?) https://t.co/QD184RtvhU pic.twitter.com/p2tcMVoZ9b
— Old Colorado Photos (@colohistory) December 9, 2023
Unlike other designs, a truss bridge can support its roadway on its structure. The load can be carried on the bottom (below the major truss structure), along the middle (through truss), and above the truss (deck truss). This makes the bridge versatile as well as economical to construct.
19. Covered bridge
The longest covered bridge is 1,282 feet long | Hartland Bridge in New Brunswick
Span range: Short
The term ‘covered bridge’ refers to a specific kind of structure, not just any bridge with a roof. It is a timber-truss bridge that distributes the weight of the load-bearing deck.
These bridges have roofs to shield the wooden materials from the weather. Uncovered wooden bridges typically endure only about 20 years due to the effects of rain and sunlight. When externally covered, their lifespan can increase by up to 100 years.
At present, there are nearly 1,600 covered bridges in the world (that are still in use). Most of them are built to cross streams and have a short span.
18. Arch Bridge
A double stone arch bridge (named Meganebashi) in Japan | Wikipedia
Span range: Short
They came into use over 30 centuries ago and remained popular until the Industrial Revolution, and advancements in material sciences allowed architects to create more advanced and efficient bridge designs.
The underside of an arch bridge looks very different than other types of bridges. All bridges have a curved underside, which looks like someone has cut a semicircle from the bottom of the bridge.
Actually, the curve design allows the load to spread out instead of pushing it in a vertically downward direction. The load is distributed to the supports at each end, called abutments. The combination of the arch and abutments makes the bridge strong enough to carry heavy loads.
17. Through Arch Bridge
World’s 5th longest steel arch bridge | Bayonne Bridge | Wikimedia
Span range: Long
It is the most common form of an arch bridge — the top of the arch rises above the deck while the base remains at or below the deck. The middle segment of the deck is supported by the arch via tie bars or suspension cables. The ends of the bridge are usually supported from below.
Sydney Harbour Bridge (in Australia), Tyne Bridge (in North East England), and Bayonne Bridge (in New York) are some well-known examples of through arch bridges.
16. Moon Bridge
Jade Belt Bridge in Beijing, China
Span range: Short
A moon bridge is a pedestrian bridge featuring a semicircular arch that completes a 360-degree circle when reflected in the water, resembling a full moon. Originating from Asian culture, these bridges were initially built in China and later introduced to Japan.
Constructed primarily using materials like stone, wood, and metal, moon bridges have a steep design, offering the advantage of not occupying space from adjacent fields. This design allows foot traffic on top of the bridge and boat traffic beneath, eliminating the need for a gradual approach to the bridge.
15. Movable Bridge
Tower Bridge in London
Span range: Short movable portion
As the name suggests, these bridges move to allow boats and barges to pass through. It can be either a vertical-lift bridge, a drawbridge, a swing (pivot bridge), or a transporter bridge.
Powered by electric motors, these bridges use mechanisms like hydraulic pistons, operating winches, or gearing. While the entire structure of moveable bridges can be quite long, the length of the movable part is usually limited to a few hundred feet due to engineering and cost considerations.
The Circle Bridge is a movable bridge for pedestrians and bicycles in the center of Copenhagen. The five overlapping circular decks were designed by artist Olafur Eliasson pic.twitter.com/fGpD0E3A8G
— Physics & Astronomy (@damnawesomevidz) February 27, 2023
The major drawback is that road traffic must be halted when the bridge is opened for the passage of waterway traffic. Additionally, these bridges require considerable maintenance due to the presence of heavy machinery and moving elements.
14. Stressed Ribbon Bridge
Leonel Viera Bridge | The first stressed-ribbon bridge constructed in Uruguay in 1965
Span range: Medium
A stressed ribbon bridge (also called a catenary bridge) is a tension structure. It has two or more suspension cables embedded in the deck. These cables follow a catenary arc (a curve formed by a freely hanging wire) between supports and provide stiffness to the bridge.
Typically constructed with concrete reinforced by steel tensioning cables, these bridges are not only aesthetic but also economical and nearly maintenance-free structures.
13. Spiral Bridge
Spiral ramp to Nanpu Bridge in Shanghai, China | Image credit: Jakob Montrasio/Flickr
Span range: Medium to long
A spiral bridge loops over its own road and is useful in steep terrain. The structure rises on a steady curve until it has completed a loop, passing over itself as it gains elevation, allowing the vehicles to gain heights in a relatively short horizontal distance.
It’s a better alternative to zig-zag roads and avoids the need for vehicles to stop and reverse direction while ascending/descending. The shape of the structure doesn’t form a spiral but a helix. Many multi-story car parking buildings feature such a design.
12. Box Girder Bridge
Open trapezoidal composite box girder during the construction
Span range: Medium to long
In this type of bridge, the primary beams are hollow box-shaped girders made of structural steel, prestressed concrete, or a composite of reinforced concrete and steel.
The box girder typically has a trapezoidal or rectangular cross-section. This design helps reduce the slab thickness, overall weight of the bridge, and construction costs, while offering greater strength per unit area of concrete. These bridges are commonly employed for highway flyovers and modern elevated structures for light rail transport.
11. Segmental Bridge
Construction of a segmental bridge on the ‘Dallas High Five Interchange’
Span range: Long (over 100 meters)
Unlike conventional construction techniques that build structures in large sections, segmental bridges are constructed in small parts called segments (one piece is installed at a time).
They are made of concrete parts that are either built at another location and transported to the construction site or built fully at the final location. Although this type of design is very economical for long spans, it requires high-tech machines and a lot of safety precautions during construction.
10. Viaduct
Glenfinnan Viaduct in the UK
Span range: Long
A Viaduct is made of a series of small spans between tall towers. Its purpose is to carry a road or railway over a valley or wetland. Although they are much more cost-efficient than bridges or tunnels with larger spans, they generally lack vertical and horizontal clearance for large ships.
The ones that are constructed over water make use of successive arches or islands. They are usually merged with tunnels or other types of bridges to cross navigable waters as viaduct sections.
9. Cantilever Bridge
Forth Bridge in the east of Scotland
Span range: Medium
These bridges are built using cantilevers, which are structural elements extending horizontally and supported at only one end. In the case of small footbridges, cantilevers may be simple beams. However, for long cantilever bridges, box girders (built from prestressed concrete) or trusses (built from prestressed concrete) are used.
Cantilevers are valuable for spanning waterways without the need for dividing piers in the river. They find applications in bridges for pedestrians, motor vehicles, and trains.
The Howrah Bridge is a balanced cantilever bridge over the Hooghly River in India, connecting two cities (Kolkata – Howrah), commissioned in 1943. pic.twitter.com/00grYK9bq9
— Historic Hub (@HistoricHub) August 1, 2022
The world’s longest cantilever bridge is Pont de Québec. It was built in Lévis and Quebec, Canada, in 1917. The project failed twice and took more than three decades to complete.
8. Suspension Bridge
Akashi Kaikyō Bridge in Japan
Span range: Medium to long
In suspension bridges, the cables supporting the deck are suspended vertically (called hangers) from the main cable. This main cable is anchored at both ends of the bridge since any load applied to the structure is transformed into a tension force.
Constructing a suspension bridge requires less material, allowing for longer spans compared to other types of bridges. Additionally, suspension bridges demonstrate better resilience against earthquakes when compared to heavier and more rigid bridge designs.
7. Cable-Stayed Bridge
Design of suspension (top) and cable-stayed (bottom) bridge
Span range: Medium
Cable-stayed bridges have been widely used since the 19th century. They consist of one or more columns (or towers) with cables directly supporting the bridge deck. The columns absorb and deal with compressional forces.
Unlike suspension bridges, these bridges have cables that run directly from the tower to the deck, forming a series of parallel lines or a fan-like pattern.
Duge Bridge is a cable-stayed bridge near Liupanshui in China. As of 2016, the bridge is the highest in the world with the road deck sitting over 565 metres (1,850 feet) above the Beipan River https://t.co/UWj9tCvR0T pic.twitter.com/3bv7Gx5mHq
— Massimo (@Rainmaker1973) July 26, 2018
They are optimal for spans shorter than suspension bridges and longer than cantilever bridges. In this range, the cable-stayed bridge remains economical and appears elegant due to the relatively small girder depth.
6. Transporter Bridge
Middlesbrough Transporter Bridge, built in 1911
Span range: Short
Transporter bridges are designed to carry a segment of roadway across a river, particularly in locations with navigable rivers or water bodies where it’s necessary for ship traffic to pass through.
It’s a rare type of bridge: fewer than 30 structures have been built so far. Of those, only twelve bridges are being used today. Middlesbrough Transporter Bridge, for example, is a 2,600-ton steel structure built across the River Tees, England. It provides a span of 570 feet to accommodate sailing ships.
5. Girder Bridge
Multispan plate girder bridge deck on concrete piers
Span range: Short to medium
As the name suggests, these bridges use girders made of either steel or concrete. The girder is the main horizontal support of the bridge that supports smaller beams on the deck. Most girders have an I-beam cross-section containing two load-bearing flanges separated by a stabilizing web.
Girder bridges have evolved significantly, progressing from limited short-span applications to cost-effective and functional structures. In today’s era, they stand out as one of the most widely used types of bridges.
Advances in material sciences and construction techniques continue to promote more widespread uses of such bridges in applications that were unheard of several decades ago.
4. Extradosed bridge
Ganter Bridge in Switzerland
Span range: Medium
The Extradosed Bridge combines the main elements of a cable-stayed bridge and a prestressed box girder bridge. It uses smaller pylons than the cable-stayed bridge and a significantly thinner girder/deck structure than that of a traditional girder bridge.
They are relatively expensive and material inefficient. Almost any span that could be built by an Extradosed Bridge could be spanned more efficiently (with less material) with a cable-stayed bridge or more inexpensively with a continuous girder bridge.
However, they are used when overall navigation clearance, height, or aesthetic requirements make girder or cable-stayed alternatives less feasible.
3. Trestle Bridge
Montana trestle bridge | Image credit: Wikimedia
Span range: Short
A trestle bridge contains several short spans supported by closely spaced frames. The trestle, which is used as bridge support, is a rigid frame made of either wood or iron.
Iron and timber trestles were widely used across the world in the 19th century. In fact, timber bridges once accounted for up to 3% of the total length of the average railroad. Although these bridges are largely outdated, they are still invaluable to infrastructure systems. For example, steel or timber trestles are often built in areas where a filled-in bridge could block potential floodwaters.
2. Cantilever Spar Cable-Stayed Bridge
Assut de l’Or Bridge in Spain
Span range: Short to medium
It’s a modern variation of the cable-stayed bridge. In these bridges, the distribution of forces doesn’t solely depend on the cantilever action of the spar (supporting tower). Both the weight distribution in the spar and the angle of the spar away from the bridge play a significant role in reducing the overturning forces applied to the spar foundation.
In some bridges, the spar is tilted at an angle counterbalanced by a structural tail. Many designs feature a curved backward spar to support the weight of the deck.
1. Side-Spar Cable-Stayed Bridge
Esplanade Riel in Manitoba
Span range: Medium
It is quite an uncommon bridge where cable support doesn’t span the roadway; instead, it is cantilevered from one side. The cable paths are usually aligned with the centerline of the bridge. Forces are transmitted through the cable stays (tension forces), then into the tower (compression forces), and then into the foundation.
These bridges are suitable for areas where the road follows an upstream direction, crosses a stream, and then turns back downstream on the other side. By incorporating a portion of the turn into the bridge structure, the curve can be made more gradual, allowing for smoother traffic flow.
Frequently Asked Questions
What is the most efficient and strongest type of bridge?
The primary objective of any bridge construction project is to create a structure that is both safe and cost-efficient. Among various bridge designs, truss bridges stand out as the strongest and highly cost-effective due to their high strength-to-weight ratio.
Model experiments demonstrate that the Howe truss bridge can withstand the maximum load. This type of truss bridge incorporates chords, verticals, and diagonals, where the vertical members are in tension, and the diagonal members are in compression.
What is the weakest type of bridge?
The strength of a bridge depends on many factors, such as materials used in the structure and construction speed, but as far as design is concerned, beam bridges have more uneven weight distribution as compared to other bridge types. The weight is directly pressed downward, placing the greatest stress on the central part of the bridge and making it the weakest point.
How are bridge designs chosen, and what factors influence the decision-making process?
The selection of a bridge design involves a meticulous process that considers several factors:
- The topography of the site, including the type of terrain, water bodies, and elevation changes
- The intended use of the bridge, whether for pedestrians, vehicles, or railways
- The expected load-bearing capacity
- The expected lifespan of the bridge and the maintenance requirements
- Budget constraints and available resources
Sometimes, designs are influenced by the surrounding architecture, historical significance, or a desire to create an iconic structure.
In addition to this, engineers also consider the environmental impact of construction materials, energy consumption, and the bridge’s long-term effects on its surroundings.
Which is the most expensive bridge ever built?
The eastern part of the iconic San Francisco–Oakland Bay Bridge had deteriorated to such an extent that it to be completely replaced. The replacement project cost over $6.5 billion (260 times more than the original estimate of $250 million), making it the most expensive bridge in the world.
This self-anchored suspension bridge crosses the San Francisco Bay between Yerba Buena Island and Oakland. The replacement span, completed in 2013, is 2.2 miles long and is expected to last at least 15 decades with proper maintenance.
Which city has the most bridges in the world?
Hamburg, the second-largest city in Germany, has the highest number of bridges in the world. Its rivers and canals are crossed by nearly 2,500 bridges, more than Venice, London, and Amsterdam combined.
How many bridges does the USA have?
There are over 614,000 bridges in the US. About 45% of these are under the financial jurisdiction of state governments, and 38% are managed by county authorities.
According to the Statista report, there are nearly 55,700 road bridges in Texas, 27,000 in Ohio, 26,870 in Illinois, and 25,800 in California.
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Thanks for explaining that the simplest form of a bridge needs to be supported by a pier at both ends. My husband and I need to have a sturdy wooden bridge put over a small stream on our property so we can drive over it. Asking about the structure of the bridge should help us find a knowledgeable contractor for the job, so thanks for sharing this info about it!