An active coil system is proposed to shield the magnetic field produced by a dynamic wireless power transfer (WPT) system used to power electric vehicles (EVs) in motion. The considered dynamic WPT is based on an electrified road with many short-track pads. A sophisticated mathematical procedure is developed to optimize the design of the active coils configuration and their excitation. By the proposed approach, the resulting magnetic field is compliant with the reference levels (RLs) of the ICNIRP (International Commission on Non-Ionizing Radiation Protection) 2010 Guidelines inside the cabin of EVs and on the side of the electrified road.