Many state-owned concrete structures, such as bridges, line the coast of North Carolina (NC), and these structures are vulnerable to corrosion and degradation in the aggressive, chloride-rich environments where they were built. The North Carolina Department of Transportation (NCDOT) created the Structures Management Unit (SMU) Design Manual in 2003 that contains different corrosion prevention requirements including the introduction of corrosive boundaries, increased concrete cover, epoxy coated steel and the addition of pozzolans and corrosion inhibitors to delay the corrosion-related deterioration of structural concrete in these environments. The Design Manual's specifications change depending on where the structure is built in relation to a corrosive boundary. It is the goal of the NCDOT policy to increase the service life of these new structures and to reduce the costs of maintenance and repair. The tidal zone was chosen for the structures in this study due to the diffusion is likely to be the dominant mode of mass transport in this zone. Studying NCDOT corrosion policy and determining whether or not it is effective was the primary objective of this thesis research. To accomplish this goal the research was divided into three tasks: field visits and data collection (concrete powder samples), laboratory testing to analyze the data to estimate the diffusion coefficient using a nonlinear regression model (minimization of squared error), and service life modeling using the Life 365 software to predict the service life , and to model the effects of corrosion on the bridge components. Given the research and results collected across the three tasks, it was concluded that the current NCDOT policy works in cases of lesser exposure, the severity of exposure was strongly related to proximity to the coast, service life modeling results indicated that the main factor impacting the service life is the tendency for the concrete member to be exposed to chloride rich waters, active corrosion was detected in the tidal zone of bridge piers and dropped off quickly at locations outside of the tidal zone, and some bridges constructed under the current corrosion policy will not have maintenance free service lives that exceed 75 or 100 years. The conclusion was bridges close to the coastline need to be addressed by modifying the NCDOT policy, salinity distributions and the distance from the open water must be measured to determine the exposure severity, and to design for a predicted service life of 70 years, a targeted diffusion coefficient of 0.06 in2 /yrs or less must be achieved.