The handling and ride comfort characteristics of a medium bus during a single lane change manoeuvre and bump pass are investigated in terms of the change of the center of gravity, stiffnesses of springs, and damping coefficients through computer simulation using DADS. Dynamic full model of the vehicle is established using tires, dampers, leaf springs, sprung mass, and unsprung masses. A driver is assumed to steer the vehicle along a prescribed path which was obtained from field tests. He was modeled as a PID controller in the simulation. In order to confirm the validity of the model, simulation results are compared with those obtained from field test. The handling and ride comfort characteristics of the vehicle are compared with root mean square values.