The United States alone is home to more than 600,000 bridges. There is no official number for bridges throughout the world. Most barely warrant the attention: they are drab examples, barren of aesthetic attraction; purely functional. World travelers, however, will have seen many innovative, elegant, and old structures around America and the globe including some bridges dating back more than 2,000 years. Design and engineering elements used during this time period still influence modern-day bridges design, but a new breed of civil engineers are developing high tech bridges that will improve the functionality, safety and aesthetics of bridges today and into the future.
To learn more, checkout the infographic below created by the New Jersey Institute of Technology’s Masters in Civil Engineering Online degree program.
Oldest Bridges in the World — America’s oldest bridge, the Pennypack Creek (a.k.a. Frankford Avenue) Bridge, is located near Philadelphia, PA, and was erected in 1697 using land granted by England’s monarch at the time, King Charles II.
The World’s oldest single arch bridge is located in Izmir, Turkey. This stone slab feature was erected in 850 BC. Besides the Arch style, there are five types of bridges. These are Beam, Truss, Cantilever, Suspension, and Cable-Stayed.
Contemporary Considerations — Today’s designs take into consideration the rigors of increasingly extreme weather patterns. Where necessary, architects consider potential damage done by earthquakes, not to mention constant use by millions of cars and trucks each year. Earthquakes have wrought devastation in Japan and in cities like San Francisco, CA, where residents await the next big upheaval. Teams of architects and engineers seek to simultaneously inspire the world’s admiration and ensure public safety.
Global Innovation: Noteworthy Bridges
The following are structures that engineers regard as examples of mastery and innovative design. Each one possesses at least one unique feature beyond structural elegance and they all surpass other comparable examples in one way or another.
• Japan: The Akashi-Kaikyo Bridge in Hyogo, Japan is the world’s longest suspension bridge and it was completed in 1998. Also known as the Pearl Bridge, this structure cost $4.3B dollars to build, but Japan’s expense was worthwhile. Pearl Bridge was designed to withstand high winds and a common experience in Japan: earthquakes.
• Thailand: Bang Na Bridge located in Bangkok, Thailand, cost £770M to build. When it opened in 2000, this six-lane, elevated design became the world’s longest road bridge at 54,000m.
• England: Blackfriars Bridge in London, England, is one of many such structures to span the Thames. This Victorian marvel was updated in 2012 to the tune of £7.3M to make room for 4,000 solar panels, making this one of just two such bridges around the world. The other example is Kuripla Bridge in Brisbane, Australia, built in 2009. London’s solar bridge prevents the emission of 500 tons of CO2 each year and spans just 281m.
• France: France’s Millau Bridge in the city of the same name is the world’s tallest bridge. At its peak, the Millau is 343m. Work ceased in 2004 at an expense of £272M and an expanse of 2460m.
• United States: Zakim Bunker Hill Bridge is located in Boston, Massachusetts. The bill was $105M to create the widest cable-stayed bridge worldwide. Zakim Bunker Hill was finished in 2003.
• United Arab Emirates: While this architectural wonder is not yet completed, the Sheikh Rashid Bin Saeed Crossing will become the longest arch bridge worldwide.
• Chinese Bridges: The longest bridge to cross an ocean, Hangzhou Bay Bridge in China measures 36,000m long and cost 14B Chinese Yuan. Six lanes of traffic move in two directions at a speed of 100 km/hr on this cable-stayed bridge in Jiaxing. China is also home to Dayang-Kunshun Grand Bridge in Jiangsu Province and the Sidu River Bridge in Yesanguan. Dayang-Kunshun is the world’s longest bridge and also a viaduct. Sidu River is the world’s highest bridge: 496M.
The Future of Bridge Design
The task of today’s architects, designers, and city planners is to unite the practical requirements of a structure with environmental prerogatives. Most countries possess at least one goal in common with every other nation: to behave more responsibly towards the environment; thus, it falls to engineers to ensure large-scale projects are in sympathy with “green” objectives. The newest bridges and some that have yet to be completed are “smart” in that they react automatically to changes in weather or to activity in the water below them. Certain ones fade into the background rather than creating a blot on the landscape. Some are designed to make space for nature and for alternative transportation.
The weatherproof Tullhus Bridge of Norrkoping, Sweden, responds to snow by melting it. A heating system is built into the structure. Certain examples in the Netherlands and Denmark take pedestrians and cyclists away from traffic but give them safer access to the same routes they would have followed by car. Green and sustainable bridges are on their way, designed to enjoy a symbiotic relationship with their natural environment and to make space for community gardens and public parks.