This video takes you through Boston's I-93 in both directions at night. Along the way, you'll see iconic, yet infamous Big Dig & Boston transportation landmarks such as the Tip O'Neill Tunnel, Zakim Bunker Hill Bridge, and the Tobin Bridge. Over the course of almost two decades, the Big Dig project replaced the Central Artery, an elevated, antiquated 6-lane freeway that divided Downtown Boston, with an 8-lane underground freeway. The project was notorious for excessive cost overruns, corruption, and scandals, but the end result is one of the most impressive public works projects ever undertaken in the United States.