NEW YORK (AP) - A new report says New York City needs to spend $47 billion over the next five years to upgrade its aging infrastructure.

The Center for an Urban Future says many of the city’s bridges, subways, sewer systems and public buildings are over 50 years old.

The public-policy think tank says 47 bridges were deemed structurally deficient in 2012.

It says in some cases the infrastructure is so old that experts “don’t even know where it is under the street.”

The institute says the city needs to invest in fixing the decaying infrastructure to maintain its quality of life and economic competitiveness.

The report recommends changes to state and city contracting rules that could bring down construction costs.

The mayor’s office says the city is investing billions to maintain and expand its infrastructure.

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