Researchers at Carnegie Mellon University have tested new drone navigation technology in an active Japanese tunnel construction site. The technology enables autonomous flights in indoor dynamic environments, allowing drones to navigate through unpredictable moving obstacles without accident. The drones were tasked with navigating the construction site while avoiding collisions with moving human workers. They were able to measure the 3D geometry of the excavation front of the tunnel, providing builders with information on which parts of the tunnel are complete and which need further scaling, without putting workers at risk. The research was presented at the International Conference on Robotics and Automation.