This paper presents the ROBO-SPECT European FP7 project, funded under the ICT-2013.2.2 programme on Robotics use cases & Accompanying measures. The main objective of the ROBO-SPECT system is to provide a robotized, faster and reliable alternative to manual tunnel structural inspection and assessment. Physical developments include the design and implementation of a multi-degree-of-freedom (MDoF) robotic system, which uses a mobile vehicle to advance along the roadway, an extended crane capable of reaching the most commonly found tunnel geometries, and a robotic arm for positioning a specifically designed ultrasonic sensor (US) Inspection Tool with high accuracy. A semi-supervised computer vision system to detect tunnel defects, a Ground Control Station (GCS) to provide a Human-Machine Interface (HMI), and an Intelligent Global Controller (IGC) to command the robot and manage communications between the different parts have also been developed. An overview of the fundamental aspects of the project architecture and design will be detailed. In addition, the developed and implemented algorithm for positioning the Tunnel Inspection Tool on detected cracks shall be presented. Finally, experimental evidence to validate the functionality of the ROBO-SPECT system in a real motorway tunnel with ongoing traffic will be provided.