This book highlights condition monitoring advances in railway engineering, where the condition monitoring serves as an essential role in the maintenance of railway engineering after decades of service. New sensing techniques have been applied in certain fields in order to determine the minor defect in the railway systems. Also new algorithms are introduced to analyze the sensed data in order to improve the accuracy and the efficiency of monitoring and detection. This book is useful for railway engineers/investigators as well the students majoring in railway engineering serving as a good starting point to learn condition monitoring in railway engineering.