Did You Know?
A Road That Will Be Paid Off in 2038
1. The estimate was $2.5 billion. The final figure was $24.3 billion.
Boston's Central Artery/Tunnel Project — the Big Dig — was approved by Congress at around $2.5 to $2.8 billion, to be finished by 1998.
Construction actually cost $14.5 billion and finished in December 2007. In July 2012, state officials publicly tallied the full figure for the first time, including interest on borrowing and legally obligated transit commitments: $24.3 billion.
That is roughly ten times the original estimate.
2. The last bond will be repaid in 2038.
The project was conceived in 1982. The debt runs to 2038 — a financial span of fifty-six years for a road that took twenty-five to build. As of 2012 the state still owed $9.3 billion in principal and interest, with annual debt service around $550 million.
Anyone born the year the Big Dig opened will be over thirty before it is paid for.
3. The physical numbers are smaller than the financial ones.
7.8 miles of highway. 16 million cubic yards of soil excavated. About 2,350 acres of concrete, laid one foot thick. 29 miles of underground utility lines relocated. To avoid disturbing nine active rail lines above one interchange, a section of tunnel was built alongside and then pushed into position — a technique called tunnel jacking.
A federal audit at one point described the project as bankrupt and called it one of the most flagrant breaches of integrity in the history of the federal highway programme.
4. It also worked.
The elevated expressway that had cut the city in half was removed. 45 parks and public plazas were built where it had stood, including the 17-acre Rose Fitzgerald Kennedy Greenway. Congestion in the centre fell sharply, though it worsened on the approaches.
The clock: Boston sits at about 71° west — nearly four degrees east of the 75th meridian that Eastern Time is built around.
That leaves the city roughly sixteen minutes behind its own solar noon. The sun reaches midday over Boston before the clock does, every day of the year.
So: a city that spent $24 billion and fifty-six years of borrowing to move a road underground, in a time zone that has been running sixteen minutes late the whole time.
Sources
- Boston Globe / Boston.com, July 2012 (exact figures released for the first time by state officials: ~$24 billion with principal, interest, and public transit commitments; $14.5 billion in construction costs; $7 billion in federal aid; final bond due in 2038)
- CBS Boston / AP ($24.3 billion; $9.3 billion remaining debt in 2012; ~$550 million annual debt service)
- Project Management Institute (original estimate $2.56 billion; final construction cost $14.78 billion; 25-year period 1982-2007)
- Taxpayers for Common Sense ($2.5 billion and 1998 target in Congressional approval; federal audit rating "bankrupt")
- Interesting Engineering (transportation of 29 miles of infrastructure line)
- MotorBiscuit (7.8 miles of highway; 16 million cubic yards of excavation; ~2,350 acres of concrete)
- Britannica (Ted Williams Tunnel construction start in December 1991; tunnel jacking method; 17-acre Rose Kennedy Greenway)
- Longitude calculation: Boston 71.06°W, Eastern Time meridian 75°W → ~16 minutes **lagging**