"A recent case study about a bridge in Monmouth County, N.J., illustrates how evolving bridge sensor technology now offers tools to far more accurately assess the structural health of existing bridges, and enables public officials to make more informed safety decisions about bridge capacity.
In effect, bridge sensor technology is a multistep process that begins with the creation of a 3-D structural model which takes into account the original design, and the accumulated modifications, repairs and upgrades made to the bridge over time, together with the areas of deterioration. Then strain sensors installed on critical structural members further refine the model. When the calibration is complete and the model confirmed as "true" to the real bridge, sequential tests with different types of loads provide data to tell engineers what the prognosis is with far greater accuracy."
Though some of the cost savings are small, the gradual upkeep of bridges rather than major overhauls helps to spread those costs over time and prevent dangerous accidents.