When it was originally built in 1889, the Poughkeepsie-Highland Railroad Bridge in Poughkeepsie, N.Y., was all about commerce and transportation, allowing people and goods to flow easily over the Hudson River 212 feet (64.62 meters) below. For years, the bridge sat unused after a fire nearly destroyed it in 1974 until a group called Walkway over the Hudson began its efforts to transform the 1.25-mile-long (2.012 kilometer) bridge into a place for the public to enjoy. The group was finally successful in its efforts when the Walkway Over the Hudson State Park opened in 2009 -- making it the longest pedestrian bridge in the world, which has since attracted more than 1 million visitors.
According to Vincent Press, a spokesperson for Bergman Associate, the design firm that spearheaded the renovation of the bridge, the environmental benefits of the project -- and this sort of pedestrian bridge generally -- are multiple. "Pedestrian bridges provide opportunities for alternative, environmentally friendly transportation modes such as biking and walking," he says. "In this case, the Walkway over the Hudson connects miles of trails on either side of the Hudson, encouraging exercise and clean modes of transportation." The fact that the bridge utilized an existing structure -- rather than starting from scratch with all new materials -- also provided green benefits, especially since lead and asbestos from the original structure were replaced with more sustainable materials.
Read on to discover how prevalent green building material is.