A vehicle air suspension can be controlled between a Standard setting of ride height and a lower, Kneel, setting. Movement to or from the Kneel setting is frozen if a door is opened or if the footbrake is applied. Alteration to the Kneel setting is prevented except when the vehicle is stationary. The suspension reverts to the Standard ride height if the vehicle is driven off or the handbrake is released. Movement of the suspension to or from a lower or higher setting is carried out sequentially to prevent headlamp dazzle. If the vehicle becomes partly supported by direct contact between the chassis and the ground (belly-out) this is detected by monitoring signals to ride height control valves and by providing a controlled re-inflation and balancing of the air springs.