Recently a challenging project has been carried out for construction of a national network for safety management and monitoring of civil infrastructures in Korea. As a part of the project, structural health monitoring (SHM) systems have been established on railroad bridges employing various types of sensors such as accelerometers, optical fiber sensors, and piezoelectric sensors. This paper presents the current status of railroad bridge health monitoring testbeds. Emerging sensors and monitoring technologies are under investigation. They are local damage detection using PZT-based electro-mechanical impedances; vibration-based global monitoring using accelerations, FBG-based dynamic strains; and wireless sensor data acquisition systems. The monitoring systems provide real-time measurements under train-transit and environmental loadings, and can be remotely accessible and controllable via the web. Long-term behaviors of the railroad bridge testbeds are investigated, and guidelines for safety management are to be established by combining numerical analysis and signal processing of the measured data.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.