Bridges are becoming safer, more durable, and longer than ever before. Bridges haven’t really changed much for many years, says Anil Agrawal, a professor of civil engineering at the City College of New York. And it would be easy for an untrained eye to miss the ways in which they have. But subtle advances in bridge technology and construction techniques are making modern bridges bigger, safer, and longer-lived.
Civil engineers have lately focused on improving safety by, for example, making bridges more resilient to fire, earthquakes, and high winds. They’re also exploring how technology can help them monitor new bridges and maintain those already in place.
For much of the 20th century, the average design life of a bridge had generally been about 50 years. To push beyond that, many new bridges now have sensors that collect data on their structural behavior and condition (though much work remains to be done to translate this data into meaningful real-time analysis).
Novel technologies—like new types of concrete or bridges that change shape to minimize wind resistance—are being studied in labs around the world, but civil engineering standards and building codes are slow to evolve. Below are five examples of how bridge technology is already changing.
Viadotto San Giorgio, Genoa
On August 14, 2018, the Ponte Morandi, a cable-stayed bridge in Genoa, collapsed, killing 43 people and severing a major artery of regional transit. Work quickly began on its replacement. Renzo Piano, a celebrity architect who was born in Genoa, designed the new bridge, and more than 1,000 laborers worked around the clock to build it in just over a year. It features a digital monitoring system and dehumidifying technology to guard against the corrosion that contributed to its predecessor’s collapse.