Massachusetts, the “Big Dig” Central Artery/Tunnel Project

  1. In an effort to replace Boston’s deteriorating and congested six-lane elevated highway with an underground tunnel system, Massachusetts Department of Transportation (MassDOT) began the Central Artery/Tunnel Project in 1982. Following a variety of delays and challenges, the first tunnel link opened in 1995.

    Upon completion, the $24.3 billion tunnel project restored 300 acres of open land, reduced total vehicle hours by 62 percent, and lowered citywide carbon monoxide levels by 12 percent. The Central Artery/Tunnel Project is estimated to annually save $168 million in time and costs to drivers.