Whole body vibration (WBV) was measured on eight surface haulage trucks in three size classes (35, 100, 150ton haul capacities). Vibration was measured at the seat/operator interface in accordance with the ISO 2631-1 standard during 1h of normal operation. Highest acceleration readings were observed in the z-axis (vertical). Estimated equivalent daily exposure values in the range of 0.44-0.82 ms(-2) were observed using the frequency-weighted r.m.s method and 8.7-16.4ms(-1.75) using the vibration dose value method. Assessment was carried out using ISO 2631-1 and 2631-5. Operators of surface haulage trucks are regularly exposed to WBV levels that exceed safety limits as dictated by the ISO 2631-1 standard. However, according to ISO 2631-5 the probability of an adverse health effect remains low. These findings confirm an apparent disagreement between the two analysis methods.