The United States civil infrastructure is aging and has been identified as an area in critical need. ASCE estimates that the current deterioration trends can have disastrous consequences in terms of costs ($520 billion by year 2040), and socioeconomic impact (loss of ~400,000 jobs nationwide). In 2009, approximately 25% of bridge fleet in the US was identifies as structurally deficient or functionally obsolete. Majority of them are typical bridges, consisting of a concrete deck supported by steel girders (stringers). It is evident that sustainable preservation of existing infrastructure represents a goal that is essential for future vitality of the US economy and the prosperity of the US society. With an aging infrastructure, it becomes crucial to make informed decisions about maintenance and preservation actions and renewal. Structural Health Monitoring (SHM) can be an important aid in this decision process, but in spite of its great potential, SHM is not applied in a widespread or generic manner, which is essentially due to the lack of reliable and affordable monitoring solutions. Thus, there is a demand for monitoring methods that are not specific to individual structure, are reliable and robust onsite, and applicable to typical bridges. These methods were successfully researched within the first term of the UTC; however new challenges were identified.