Raising the Bayonne Bridge

The Bayonne Bridge crosses the Kill van Kull, one of the entrances to New York's extremely busy harbor and my nominee for the world's coolest river name. The bridge used to look like this. It was built in 1931, its steel arch a modernist monument with many admirers. The roadway was 151 feet (46 m) above the water.

That was plenty high for big ships of the twentieth century, but in the twenty-first they have gotten even bigger. So more than a decade ago the Port Authority realized that something would have to be done about the Bayonne Bridge. After considering proposals to completely replace the bridge they decided to keep the old structure but raise the roadway. The roadway, after all, is not a structural element of the bridge; the steel arch provides all the strength and support. Here you can see the upper roadway being built 65 feet (20 m) above the old one. The cost of the construction was $748 million.

On September 7, one of the world's biggest ships, the "neo-Panamax containership" Theodore Roosevelt, sailed under the bridge, showing off its new height.

The high-level bridge illuminated for its opening. There's a cool article about this by Ian Frazier in the New Yorker.