Longest International Bridge
I like extremes. The middle is boring. I’m also fairly certain that if I feature one end of the spectrum such as the Shortest International Bridge, that I’ll also feature the other end eventually. It’s going to be difficult to compete with that earlier article. Reader participation during the hunt and resulting discussions were truly memorable. However I’ve uncovered several interesting tidbits at the other end and the search was far easier thanks to a handy list I could parse for candidates.
Some definitional issues presented themselves. "International" wasn’t a problem. I think there’s a level of consensus on what constitutes a sovereign nation, and thus what it means for a bridge to span a border between two nations. "Longest" on the other hand lends itself to all sorts of subjective and favored interpretations that may differ between individuals. Should we differentiate between huge lengths of steel crossing massive divides in a single mighty span from those of the lowly causeways that barely skim the surface with hundreds of inconsequential tiny chasms? Ultimately I went with the latter definition by considering the entire bridge length regardless of spans. Others will likely disagree and that’s fine.

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(1) King Fahd Causeway between Saudi Arabia and Bahrain
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This is why a decision about total bridge length versus spans matters. This one is described as a causeway. Nonetheless it stretches an impressive 25 kilometres (15.5 miles) and provides the only road access between the island and Kingdom of Bahrain and the outside world. The King Fahd Causeway Authority estimated that more than 17 million people crossed here in a year.
Imagine the challenge this would create with border controls. The Causeway Authority came up with a novel solution: a border station built upon an artificial island in the middle of the Gulf of Bahrain. They like to describe it as "two connected islands" with the western island in Saudi Arabia and the eastern island in Bahrain. However it’s rather obviously a single barbell-shaped island with an international boundary passing through the narrow neck. The 600,000 square meters (163 acres) of dry land is almost a mirror image of itself like some massive Rorschach inkblot. There are two mosques, two Coast Guard stations, two observation towers, two sets of restaurants and of course two passport controls.
(2) Øresund Bridge between Denmark and Sweden
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The Øresund Bridge connects Copenhagen, Denmark to Malmö, Sweden. Border controls aren’t an issue here because it’s fully within the Schengen Area. Nonetheless it’s still a national and linguistic divide. That makes it Øresundsbroen in Danish and Öresundsbron in Swedish, which provides me with an always-welcome opportunity to use funky punctuation.
The Øresund Bridge extends 7.8 kilometers (4.9 miles) and includes a tunnel component. Now I think you’re beginning to understand how twisted this "longest" category can become.
(3) Libertador General San Martín Bridge between Uruguay and Argentina
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I love how these examples shift around the world. First the Middle East, then Europe and now South America. The San Martín Bridge is a cantilever structure over the Uruguay River stretching just shy of 6 kilometers (3.7 miles) from Uruguay to Argentina. This is the closest roadway between the two capital cities, Buenos Aires and Montevideo, although it would probably be a lot more convenient to take a directly-routed ferry instead.
Sixth place on the list goes to another bridge between further north along the same river, also crossing between Uruguay and Argentina: The General Artigas Bridge at 2.3 kilometres (1.5 miles). Thus, Uruguay and Argentina earn a special honor on the international bridge list.
(4) Sault Ste. Marie International Bridge
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North America comes up on thd list too. The Sault Ste. Marie International Bridge extends from Canada to the United States over the St. Marys River. We’re starting to get further down the list. This one stretches "only" 4.5 kilometres (2.8 miles). The bridge connects two different towns named Sault Ste. Marie, one in Ontario and the other in Michigan.
As part of Canada Day festivities, and as an extension of friendship between two neighboring nations, authorities open the bridge for the International Bridge Walk annually on a Saturday close to July 1.
The walk begins at the Norris Building parking lot of Lake Superior State University with speeches from officials of both Saults and the singing of ‘O Canada’ and ‘The Star Spangled Banner’. Participants begin walking about 9:00 a.m. and proceed west on Easterday Avenue and to the on-ramp near the bridge’s toll plaza and finish at a casino parking lot in Canada.
I’m a little surprised that this event has survived within a post-911 world. I wonder how they handle all the security? Participants do have to present suitable identification before starting, but how do authorities make sure nobody sneaks into the crowd? Has anyone in the 12MC audience participated in this event?
Postscript
I’m sure someone will ask so I might as well post it now. The fifth longest international bridge is the Giurgiu-Rousse Friendship Bridge (map) between Bulgaria and Romania at 2.8 kilometres (1.7 miles).
Did I miss any of your favorites?
