We build bridges for many reasons. Some bridges help us build layers of transit areas, some go over uneven land, and others span bodies of water. Bridges come in many sizes and shapes. Let’s take some time to look at the different kinds of bridges and the purposes they serve. We’ll also consider the largest bridge in the world and show you where it’s located, who it serves, and when it was built!
What Is a Bridge?
Although this question may seem asinine, it’s something we need to discuss. A bridge is any structure that is designed to span an obstacle, like water or land, without completely blocking the path below.
Many types of bridges exist, and we’re going to briefly review the different types of them. Generally speaking, seven different types of bridges exist. These types include:
- Beam Bridges
- Cable-stayed Bridges
- Suspension Bridges
- Truss Bridges
- Arch Bridges
- Tied Arch Bridges
- Cantilever Bridges
Of all these bridges, the most common ones include the beam, suspension, and arch bridges. These structures are often seen spanning rivers and other waterways to allow people to cross. However, none of these types of bridges are in the top ten longest bridges.
In fact, the largest bridges are all a type called a viaduct. That is why when we discuss the largest bridges, we need to think about either narrowing our focus or expanding it. In our opinion, since we’re going to look at the biggest structures in the world, we choose to be more inclusive. We’re going to allow viaducts into the conversation.
That way, we can see the most impressive feats of bridge engineering.
How is a Viaduct Different from a Bridge?
A viaduct is a type of bridge or merely a bridge-like structure, depending on who you ask. These structures are usually a series of bridges featuring intermediate supports, usually arches. Viaducts tend to connect points of land that have roughly the same elevation.
They can be used to span land or water, providing a way to connect two sections of a city or to build a long railway through waterlogged lands.
The differences between a viaduct and a bridge are relatively small on the grand scale of things, but they are worth mentioning and recognizing. Now that we know how to tell these structures apart, we can focus on measuring them.
Measuring the Largest Bridge in the World
Taking the measure of a bridge can be rather difficult. Two questions we must ask are: where does a bridge start and where does it end? Some people may measure starting from the first span and others might measure from the on-ramp to the bridge. For our purposes, we’re going to use the measurements provided by the commissions that oversee the bridges. That’s the only reliable source of data for most of these.
Another question we must consider is, what measure are we taking of a bridge? In other words, what do we mean by the largest? For our purposes, we’re going to measure bridges by their length. That is the most effective way to gauge the largest bridge out of them all. We will include other statistics about the bridge when possible, including how many lanes it has and more.
Without further ado, let’s look at some of the exemplary bridges from around the world!
What Is the Largest Bridge in the World?
The largest bridge in the world is the Danyang–Kunshan Grand Bridge, a 102.4-mile viaduct in China. The bridge was completed in 2010, and it supports a part of the Beijing-Shanghai High Speed Railway. This viaduct took four years to build and opened to the public in 2011.
This bridge connects the cities of Shangai and Nanjing, halving the previous amount of time that it took to reach the cities. Now, it only takes about two hours to travel between these two major hubs instead of four and a half hours.
The bridge runs through a variety of different lands including cities, lakes, and somewhat rural areas. This structure is truly a marvel of engineering that took a great deal of effort, planning, and perfect construction to complete.
The second-longest bridge in the world is the Changhua-Kaohsiung Viaduct, and it is located in Taiwan. This viaduct supports part of the Taiwan High Speed Rail, and it measures 97.7 miles long! It connects Baguashan to Zuoying, and it’s designed to be earthquake resistant.
Not only can trains stop on the bridge during earthquakes, but the bridge is also designed to be easily repairable following a seismic event.
What is the Longest Bridge Over Water?
The longest bridge that is continuously over water is called the Lake Pontchartrain Causeway, and it measures 23.83 miles long. This bridge is located in Louisiana, United States.
The causeway consists of two parallel bridges that cross Lake Pontchartrain, connecting Mandeville with Metairie, a suburb of New Orleans. This structure is so long that drivers lose sight of land when they’re in the middle of the bridge. Also, over 9,500 pilings support the bridge!
Most importantly, this bridge shortens the former drive around the lake by almost an hour and provides another way in and out of New Orleans. After all, this city has been evacuated due to hurricane threats and has been struck by many powerful hurricanes.
This bridge is considered the longest one over water because all of it is over water, but longer bridges that have significant portions over water exist. For example, the Hong Kong–Zhuhai–Macau Bridge measures over 34 miles.
Yet, part of that goes through tunnels, and portions of the bridge are built over land. The bridge itself only passes over 16.1 miles of water. Thus, when we’re talking about the longest continuous span of a bridge over water, the Lake Pontchartrain Causeway is considered the winner.
The largest bridge in the world is located in China, and it is the only bridge that measures over 100 miles long. This bridge, and others, require a lot of materials, work, and planning to bring to fruition. The future of bridge-building for the sake of transit is brighter than ever and could work hand in hand with mass transit.