Across the country, bridges are crumbling and collapsing. More than 50,000 bridges are falling apart, including nearly 500 in Massachusetts.

In December, a New Hampshire woman on her way to work in Boston was hit by falling debris in Newburyport, Massachusetts, under the Whittier Bridge. It shattered her sunroof.

NBC10 Boston's Investigators checked area bridges. For example, under the Massachusetts Turnpike bridge near Boston University, concrete is crumbling top to bottom, steel is rusting and corroding. We also found holes rusted through in support beams.

Ilyas Bhatti is the former commissioner of the Metropolitan District Commission and oversaw bridges in the state for years. He now teaches at the Wentworth Institute of Technology.

"All the infrastructure is getting a D or less than D," he said. "Overall the state is not very good."

Structurally Deficient Bridges

Bridge data from the Massachusetts Department of Transportation Highway Division Bridge Inspection Management System.

Data as of Oct. 2016

A new report from the American Road & Transportation Builders Association shows how bad it is. According to government data, 54,259 bridges are "structurally deficient."

"50,000 is a very large number," Bhatti said. "And the question comes - are we slipping into being the third world countries?”

In Massachusetts, there are nearly 500 structurally deficient bridges. Drivers pass over them 10 million times a day. Are bridges inspected enough?

"Until there’s an emergency, no action is taken," Bhatti said. "Inspections are done but should be expanded."

The Massachusetts Department of Transportation declined to allow NBC10 Boston's Investigators to go along on an inspection.

Some bridges have signs saying no trucks over the bridge or no trucks over six tons.

"That’s because the bridge is not up to the standards," Bhatti said. "The current standards.”

Experts say at the current rate of repair on bridges nationwide, it would take 37 years to fix the country’s bridges.

"The problem with our bridges is that we built great bridges going back to the time of President Eisenhower," Bhatti said. "He started the interstate highway system. Great bridges, but then forgot about maintenance.”

Some of the Massachusetts bridges on the list date back to the 1850s. They were not built for today’s traffic or 18-wheelers. The bridges are crumbling, in need of repair. New technology may help speed up the process.

"You take the case of the Tappan Zee Bridge, it will take six months to a year to erect the inspection platforms," Bhatti said. "Now we can send drones and the drones take thousands of pictures a minute.”

Those drones take pictures all over the bridge, including underneath, so engineers can more quickly diagnose the problems. Some of the bridges have been on the list with repairs not made for years.