When I was studying in Boston years ago, I used to hear locals talk about the Big Dig. It was a mega infrastructure project to build underground tunnels to replace road-level and raised artery roads that had become congested. Planned since the 1980s, construction began in 1992 with an estimated cost of US$2.6 billion.
When I was there in 2001, construction was heavily under way but the running joke was that it was a Big Dig that would go on forever, because of multiple delays, and an uncertain end point. By the time it was completed around 2005, the cost had swelled to US$14.8 billion.