The average bridge is designed for a 50 year lifespan.  Today however, most bridges are at the end of their expected lifespan and are also carrying heavier loads than they were originally designed for.

This real time technology similar to an EKG monitors the health of bridges by monitoring fatigue cracks and whether they are growing. Watch as Matech Corp shows how they use electrochemical fatigue sensors to determine the health of bridges. Watch Video Here

This highlights a larger problem that needs addressing: Bridges throughout the nation are at or passed their lifespan.  ASCE recognized this and has been attempting to address this for almost a decade: