An active, nonlinear, pneumatic suspension applicable to passenger railcars is described. Standard on-off valves modulate pressure differences between dual opposing airbags to attenuate vibration and create guidance forces. Improved vibration isolation over that of conventional passive suspensions is achieved at low power levels. Guidance forces are provided with small suspension travel using short bursts of compressed air taken from vehicle supply reservoirs. Acceleration, relative displacement, and pressure transducers provide the control signals required for stabilization, feedforward guidance commands, and disturbance attenuation. Simulation results indicate that performance comparable to hydraulic servosystems can be attained with substantially reduced system complexity and power requirements.