GPR mobile mapping system 3D (GMS3) is a system that combines three-dimensional ground-penetrating radar (GPR) subsurface data synchronized with 360° camera surface mobile mapping system (MMS) imagery to provide an integrated surface–subsurface spatial information database where subsurface features are easily localizable from surface imagery. The MMS system also provides correction of raw Global Navigation Satellite System (GNSS) data through camera vector (CV) processing of surface imagery, allowing for high-precision localization of the database. The system’s main applications are road subsurface cavity detection and mapping for prevention of sinkholes and mapping of buried pipes and other underground infrastructure. Both applications are in high demand in Japan, in part due to the country’s high susceptibility to earthquakes, as well as its delay in undergrounding of overhead cables. It is expected that GMS3 can be a valuable spatial information system in subsurface and surface mapping.