A semi-automated method for extracting vertical clearance and cross sections in tunnels using mobile LiDAR data

The validation of the developed approach is done using real-life case study, a road tunnel in southern Galicia, Spain. An accuracy of 100% in detection of cross sections is achieved. Only one of the cross sections shows a relative error in vertical clearance measurement higher than 1%. The results demonstrated the effectiveness of the developed approach for computing vertical clearances and demonstrating that tunnel management activities can definitely benefit from using mobile LiDAR by minimizing survey time and increasing productivity in dangerous environments.