Areas in the vicinity of trunk roads are exposed to high levels of noise and may pose high health risks to residents. To assess the health risks and formulate effective noise mitigation measures, prediction of road traffic noise is crucial. Addressing this issue, the author has developed a road traffic noise prediction system that allows prediction of sound levels using a database of road network. The objective of the present study was to predict road traffic noise in the vicinity of the trunk roads using a Digital Road Map Platform (DRM-PF) database, which contains nationwide road geometries and traffic settings of trunk roads. Predicted sound levels were compared with actual measurements and noise maps were created to demonstrate the feasibility of assessing noise exposure and associated health risks in the vicinity of trunk roads in Japan. The results show a generally good agreement between predicted and measured levels, while challenges remain in accurate prediction in a number of environments, mainly due to the lack of accurate geometries. The extensive coverage of the DRM-PF database throughout Japan enables noise mapping in arbitrary regions near trunk roads, which would contribute to making noise policy.