When we build infrastructure, we rarely consider the life-cycle cost. In addition, visual inspection of bridges can not do the whole job of evaluating the safety of infrastructure, such as bridges, parking decks, etc. Structural monitoring is a recent method that uses the latest in sensor technology, wireless data, and the Internet to give a 24 x 7 stream of structural data – including through seasonal fluctuations (temperature).
A new client, LifeSpan Technologies (http://lifespantechnologies.com) developed a patented sensor and has direct experience with Departments of Transportation (DOT), major corporations, etc. This is a federal issue and will take national action, possibly by congress to mandate an improvement to the current, visual-only method of assessing the nation's infrastructure. [note: we have done work for LifeSpan Technologies on this subject.]