North American Railroads and the United States Department of Transportation (US DOT) Federal Railroad Administration (FRA) require periodic inspection of railway infrastructure to ensure the safety of railway operation. Tracks that are subjected to heavy haul or high-speed traffic necessitate frequent inspection and more stringent maintenance requirements, but present railroads with less time to accomplish it. The international railroad community has undertaken significant research to develop innovative applications for advanced technologies with the objective of improving the process of visual track inspection. Some of these technologies are currently in use or under development for a variety of railroad inspection tasks, both wayside and mobile. This paper presents an overview of different systems for condition monitoring applications for inspection of railway components. These technologies, in conjunction with defect analysis and comparison with historical data, will enhance the ability for longer-term predictive assessment of the health of the track system and its components, more informed and proactive maintenance strategies, and improved understanding of track structure degradation and failure modes.