You can now read 10 articles in a month for free on BostonGlobe.com. Read as much as you want anywhere and anytime for just 99¢.

The Boston Globe

Metro

Add interest, and Big Dig cost expected to top $24b

As construction wound down on the Big Dig nearly a decade ago, officials disclosed that the cost of the highway megaproject had escalated to nearly $15 billion. Now, for the first time publicly, state administrators have tallied the full cost of the work — principal and interest, plus legally obligated transit commitments — and it is some $10 billion higher.

The highway-tunnel work cost $14.5 billion, with the state using $7 billion in federal aid and borrowing the rest. Add interest, and the total figure shouldered by state and federal taxes and tolls will be $21 billion by the time the final bond is paid off in 2038, Dana ­Levenson, chief financial officer for the Massachusetts Department of Transportation, told a legislative committee Tuesday.

Loading comments...

You have reached the limit of 10 free articles in a month

Stay informed with unlimited access to Boston’s trusted news source.

  • High-quality journalism from the region’s largest newsroom
  • Convenient access across all of your devices
  • Today’s Headlines daily newsletter
  • Subscriber-only access to exclusive offers, events, contests, eBooks, and more
  • Less than 25¢ a week