HARI SREENIVASAN, PBS NEWSHOUR WEEKENDANCHOR:

The nation's infrastructure received an overall grade of "D- plus" in a report card published this week by the American Society of Civil Engineers, the same grade the group issued in 2013. Among the 16 categories graded: bridges received a "C-plus"; roads, dams and airports, a "D"; while mass transit came in with a "D-minus."

The group's senior managing director, Casey Dinges, joins me now from Washington to explain these very low grades.

Mr. Dinges, these are not grades that we would want to see on any child's report card. Yet, I guess we tolerate them at such crucial things as the roads and bridges we drive on and the water that we drink.