Road Bridges: Over the Top

Author: Michael Vogel

Oct 05, 2022 Innovation

Road bridges are imposing structures. Both the longest and the highest are located in China, the largest in France. And some bridges even sport restaurants, Ferris wheels, or kites.

No one knows who the first person was to benefit from a bridge, nor when this happened. Do tree trunks laid across a ditch, a trail of large stones in shallow water, or some vines stretched across a ravine already count as bridges? In Switzerland, between today’s Rapperswil and Hurden, a crossing connected two settlements on Lake Zurich as early as 1500 BC. It is considered one of the oldest bridges with documented remains. Initially, bridges were often only usable for people. But bridges that were large enough for wagons to be pulled across were built as early as antiquity. Today, reinforced concrete and steel predominate in bridge construction.
A bridge higher than the Eiffel Tower
The tallest road bridge in terms of total height of the structure is located in the south of France: It is the Millau Bridge, across which the highway crosses the Tarn Valley. Its tallest pillar is 343 meters high, slightly higher than the Eiffel Tower. The bridge consists of a 245 meter high concrete pillar that supports the road deck from below, and a 98 meter high superimposed steel pylon, from which the road deck is suspended by cables running at an angle. The bridge, which went into operation in 2004, is not quite 2.5 kilometers long.
While the Millau Viaduct is the tallest bridge structure, the Beipanjiang Bridge in southwest China spans the deepest valley floor. At one point, it descends 565 meters vertically from the road deck. This makes the Beipanjiang Bridge the highest bridge in the world. Like the Millau Viaduct, it is a cable-stayed bridge and part of a highway route. The 1.3 kilometer long structure was opened to traffic at the end of 2016.
The Beipanjiang Bridge has a span of only 720 meters, which means it has a maximum distance of 720 meters between two pillars. In contrast, the span of the Çanakkale 1915 Bridge is almost three times as large: around 2020 meters – a record. The 3.8 kilometer long highway bridge is located in Turkey and went into operation in the spring of 2022. It is designed as a suspension bridge, like the Golden Gate Bridge in San Francisco. The structure spans the Strait of the Dardanelles and is thus an alternative route to crossing the Bosporus Strait, which connects the European part of Turkey with Asia Minor.
The longest over-sea bridge runs between Hong Kong and Macau
In the quartet of records consisting of size, height, and span, we’re still missing the record for length. According to the Guinness Book of Records, the Hong Kong-Zhuhai-Macau Bridge has been the ultimate benchmark since 2018, or more precisely: It’s the longest bridge to cross water. As the name suggests, the structure in China connects the cities of Zhuhai and Macau with Hong Kong. A length of 55 kilometers is mentioned for the total structure. It consists of a twelve kilometer long connecting section in Hong Kong, a 29.6 kilometer long cable-stayed main bridge, and the 13.4-kilometer-long connecting section in Zhuhai. In part, the route even runs under water so as not to interfere with shipping traffic. In addition, three artificially raised islands were also created for the structure. The new connection turns a one hour ferry crossing into a 40 minute car ride. Incidentally, left-hand traffic applies in Hong Kong and Macau, and right-hand traffic in Zhuhai – the transitions take place at the respective end points.
The Evergreen Point Floating Bridge in the USA also crosses water, but the road deck partially floats on the water for more than 2,350 meters. This makes the structure the longest pontoon bridge in the world. It crosses Lake Washington and connects Seattle with suburbs in the east. The structure opened in 2016, replacing an older pontoon bridge. It now bears the official name “Governor Albert D. Rosellini Bridge”. By mere chance, the four longest pontoon bridges in the world are located on the west coast of the USA, all in Washington state.
Road bridges as tourist magnets
For some bridges, the builders and financiers have come up with special features that have nothing to do with the functionality of the structure, but are intended to attract tourists. For example, the Slovak National Uprising Bridge in Bratislava has a tower restaurant with a viewing platform. It is located on the cable-stayed bridge’s 85 meter high pylon. The 430 meter long bridge is probably the most famous Danube bridge in the city and connects the Petržalka district with the Old Town.
Not a restaurant but a Ferris wheel stands on the Yongle Bridge in the eastern Chinese port city of Tianjin. The entire structure was completed in 2008 and has since become one of the city’s landmarks. At night, it is an especially pretty sight from the shore, because the illuminated 120 meter high Ferris wheel is reflected in the river under the bridge.
There’s also a bridge shaped like a dragon in the Vietnamese city of Da Nang. The aptly named “Dragon Bridge” crosses the Han River in the city center and was opened to traffic in 2013. It is just under 670 meters long. On Saturday and Sunday evenings, the dragon’s head, which stands 70 meters above the road deck, spits fire for three minutes, followed by water. An eye-catcher.
Meanwhile, the Eshima-Ohashi Bridge in the south of Japan’s main island has become an eye-catcher in photos. It connects the cities of Matsue and Sakaiminato. Taken from the right position with a telephoto lens, the bridge’s ascent and descent look extremely steep. But that’s just an optical effect created by the telephoto. At five and six percent respectively, the gradients are by no means extreme. Many Alpine passes, for example, are steeper.