Urban Projects Expert on Big Dig Oversight

The Big Dig's troubles have raised numerous questions about how the almost $15 billion project could have suffered from such a serious lack of effective oversight.

Some argue that cost overruns and increasing pressures to get the job done on time contributed to that lack of oversight.

Bob Oakes speaks with David Luberoff, director of the Rappaport Institute for Greater Boston and co-author of the book "Mega-Projects: The Changing Politics of Urban Public Investment."