A human body model has been developed for conducting personal computer simulations to evaluate physical work loads, especially muscle loads, associated with the driving position and arm and leg motions. The validity of the model was confirmed by comparing estimated work loads with electromyographic measurements. Correlation analyses were conducted to examine the relationship between the estimated loads and subjective evaluations. The results indicated the regions of the body where loads had the largest impact on the perceived sensation of physical effort and were used to derive an index for evaluating the overall work load of the entire body. The simulation method was used to evaluate control switch positions, driving position and vehicle entry/exit motions.