Across the US, over 140,000 bridges are no longer structurally sound or able to keep up with increased traffic. Chances are you drive over at least one of these bridges every day- do you know where they are, and what the problems are with them?

During the 2013 State of the Union, President Barack Obama mentioned the need to fix the nearly 70,000 structurally deficient bridges. On the Daily Show, Jon Stewart responded, saying "70,000 structurally deficient! I mean, come on! Shouldn't you have opened with that?"

These bridges in need of repair present a huge problem, but also a big opportunity. Some economists say that one possible way out of the recession would be to inject money into the economy by increasing spending on fixing these bridges.

A structurally deficient bridge is not necessarily unsafe to drive on. However, in order for the bridge to remain in service for the long term, significant work needs to be done - soon.