As described in the final report, this study developed and evaluated in the laboratory a multi-parameter corrosion monitoring system for existing reinforced concrete structures in chloride-laden service environments. The study improved and validated the SwRI corrosion sensor prototype for use in the concrete corrosion monitoring system; developed algorithms for quality control and interpretation of the sensor data; made viable recommendations to implement the corrosion monitoring system for existing DOT inventories of RC bridges; and delivered a deployable prototype corrosion sensing system for DOTs to continue field evaluations. The performance and reliability of the SwRI corrosion sensor were confirmed by the benchmark test in simulated concrete pore solutions. However, once active corrosion is initiated and a great amount of chloride is present, the multi-electrode array sensor (MAS) probe may no longer serve as a good tool to predict the corrosion rate of rebar unless more research is conducted to establish such prediction or correlation. The performance and reliability of the SwRI corrosion sensor were also confirmed by embedding it in a paste specimen, while some issues with firmware and possibly graphite reference probe were identified. While more research is needed, the paste specimen test also imply that the MAS probes, Cl probes and pH probes all have great potential to work properly under a reasonably low electric field.