This paper describes the development of a Bus-Exposure Matrix (BEM) to retrospectively estimate Swiss bus drivers’ exposures to 10 physicochemical hazards, including electric and magnetic fields. Measurements in representative buses were combined with technical inventories and INLA modeling to estimate annual exposures from 1985–2022. Reported trends include increasing peak noise and electric-field exposures over time, alongside decreases in several air pollution, vibration, and noise metrics.