For bridges, the nearest-term opportunity is likely magnetic inspection. My team and I co-authored a review, which has not yet been peer-reviewed, on quantum magnetometers for infrastructure inspection. These sensors identify signals from induction responses, magnetic flux leakage, stress, corrosion and operational currents.
In plain terms, these sensors may help map weak magnetic fields near steel, cables or electrical conductors. Changes or disruptions in these local magnetic fields can reveal hidden rust, snapped wire strands inside a thick suspension cable, or abnormal stress points in the steel before a crack even forms.
