These envelope-pushing highways, skyways, and landmarks cross the divide between infrastructure and innovative desig.

Bridges have long captivated public imagination, their bold and dramatic contours boldly defying gravity as they span harbors, valleys, rivers – even oceans. Few modern structures are as iconic as the San Francisco Bay Bridge or Tower Bridge in London. Since the construction of these behemoths typically represents a substantial communal investment, they understandably bring a sense of pride for the towns, cities, or nations they help connect and grow. The balance, though, between artistic design and sound structural engineering is delicate, for nothing quite defines a skyline like these massive projects. Here are a few recent examples of how bridge designers and engineers are bringing together form and function in this most visible kind of infrastructure.

 

The Octavio Frias de Oliveira Bridge

In one of the most ambitious and innovative bridge designs to date, the Octavio Frias de Oliveira bridge in SãoPaolo, Brazil is the only one of its kind in the world. Supporting two curving tracks with a single massive concrete support, the bridge spans more than 900 meters of the Pinheiros River and climbs more than 148 meters into the sky. The two roadways are elevated at slightly staggered elevations, allowing them to gently curve past one another under the support tower, which boasts dozens of steel support cables. The bridge opened to the public in 2008, and has since become a popular tourist destination. Workers installed LED lighting to show off the bridge’s unique architecture and groundbreaking design features. The project cost about $184 million to pull off, with an additional $40 million for paving, drainage, and illumination. 58,700 cubic meters of concrete were poured to specifications of architect Paulo Filho João Valente, and despite its irregular engineering, the structure can withstand not only the heavy daily traffic but also winds up to 250 mph. Not surprisingly, the dramatic motorway is often featured in some of Brazil’s most recognizable car advertisements.

 

Jiaozhou Bay Bridge

In the booming economy of China, a growing infrastructure is trying to keep up with an upwardly populace. The recently completed Jiaozhou Bay crossing spans 26 miles of open sea, making it the longest sea bridge in the world. Construction took more than four years and employed more than 10,000 people at a stated cost of about $1.5 billion (though some suspect it is much higher). With 450,000 tons of steel and 2.3 million cubic meters of concrete, the bridge is built to withstand typhoons, hurricanes, earthquakes, ship collisions, and the six lanes of traffic crossing between the Huangdao District, the City of Qingdao, and Hongdao Island. The bridge’s unique T shape design allows for three different entry and exit points, and is supported by over 5,000 pillars. China seems intent on maintaining its top-dog status – the previous record was held by its own Hangzhou Bay bridge at 22.5 miles, near Shanghai. Both stand as a testament to China’s continuing economic rise and strong ambitions for the future.

 

The High Line

This renovation project in downtown Manhattan may stretch the genre, but was too noteworthy to pass up. Once an abandoned elevated train system, the extensive bridge-way has been partially converted to an aerial park for pedestrian traffic, offering a unique natural preserve in the middle of the country’s most iconic urban jungle. The railway sat in disuse for decades and was slated for demolition until a group called Friends of the High Line stepped in to save the bridge-way. After approval from the city in 2002, construction began on the greenway in early 2006 under the guidance of architects Diller Scofidio + Renfro. The project has been divided up into three stages, two of which are complete as of June of this year, with funding already available for work to begin on the final stage. The walkway’s success has inspired similar projects in dilapidated areas of other major cities, including Philadelphia, Chicago, St. Louis, and even Mexico City. The High Line project stands as a symbol of urban renewal, sustainable architecture, and the potential of innovation and creativity in the design field, while its astonishing success has left New Yorkers walking on air.

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