Routine inspection and monitoring of railway tracks and facilities is an important task to ensure operational safety. The existing standard manual and rail vehicle based investigation are substantially time consuming and inaccurate. UAV-based autonomous monitoring and inspection technology has shown great potential in many fields and industries but it has been rarely explored in railway transit systems. UC Berkeley California Partners for Advanced Transportation Technologies   (PATH) in partnership with Bay Area Rapid Transit (BART) investigated  the application of unmanned aerial vehicles (UAV) and autonomous rail-based vehicles for autonomous routine inspection of the  BART rail system, as well as rapid assessment of the BART system in case of emergency (train derailment, criminal events, earthquake, fire, and chemical leakage). The UAVs may also be utilized to monitor areas of interest, people or objects within BART’s system and provide real-time visual and location information regarding where the events occur. The primary purpose of the UAV@BART application is to reduce human labors on routine maintenance tasks, and improve operational safety and personnel security by utilizing UAV technologies in BART system inspection and monitoring.