"Our bridges are getting old, many of them are 50 to 60 years old, and that is their life," said Mufti, also the president of Intelligent Sensing for Innovative Structures (ISIS) Canada, a national research network which studies installing remote sensors in structures like bridges to inspect their safety.

"The sooner, the better. Some of these (bridges) are quite old and we don't even know what's happening to them," said [Mufti]. "Visual inspection is not a sure shot to know. If a person is healthy they can be having some sort of really difficult illness we can't see at the surface."

"We have some wood bridges, we have some concrete bridges, we have some steel bridges," he said. "Those bridges that are old, we have to devise a system to say, 'OK, so much life is gone, what is remaining?' and then see how far we can extend it before they collapse."