Medary.com

Officially, Dec. 31 marks the end of the joint venture that teamed megaproject contractor Bechtel/Parsons Brinckerhoff with the Massachusetts Turnpike Authority to build the dizzying array of underground highways, bridges, ramps and a new tunnel under Boston Harbor - all while the city remained open for business.

The project was so complex it's been likened to performing open heart surgery on a patient while the patient is wide awake.