The continued functionality of a nation’s infrastructure systems, e.g. bridges, is a necessary pre-requisite to her continued social and economic development. However, in about 15 years, 50 percent of our bridges will be over 50 years old, inducing an unprecedented commitment of both financial and human resources. Hence, a successful Structural Health Monitoring (SHM) strategy, providing reliable, economic and easy to conduct inspections, is essential to engineers and government authorities responsible for the up-keeping of such systems. Such a strategy will involve the collection of vibration response data of the bridge, through the analysis of which an instantaneous assessment of the bridge’s current state of health can be made.