Central Artery in the context of "Big Dig"

The West Side Elevated Highway (West Side Highway or Miller Highway, named for Julius Miller, Manhattan borough president from 1922 to 1930) was an elevated section of New York State Route 9A (NY 9A) running along the Hudson River in the New York City borough of Manhattan to the tip of the island. It was an elevated highway, one of the first urban freeways in the world, and served as a prototype for urban freeways elsewhere, including Boston's Central Artery.

Built between 1929 and 1951, the highway had narrow confines—which could not accommodate trucks—and sharp S exit ramps that made it obsolete almost immediately. Maintenance was minimal, and the use of corrosive salts to de-ice the highway in winter accelerated its decay. When chunks of its facade began to fall off due to lack of maintenance, and a truck and car fell through it at 14th Street in 1973, the highway was shut down, and a debate began over whether to renovate it or dismantle it. Attitudes to urban planning had changed in the intervening decades, and the decision was made not to repair the decaying structure.