After an enumeration and classification of oscillatory systems, the question of the generation of oscillations is dealt with. The principal source of oscillations to be mentioned is the unevenness of the roadway. This unevenness can be characterized as a random variable by means of a frequency spectrum. Curves resulting from measurements are given. Tyre non-uniformity and wheels are another source which has recently drawn more attention. Then is examined what influence the vehicle's own characteristics may have upon the two criteria just mentioned. Suspension must be such that the main frequencies of the vehicle's structure remain low and independent of the load. Shock absorbers must be designed to work with little friction forces and must dissipate a definite quantity of oscillatory energy: that which corresponds to maximum sensation for the passengers and to the greatest amplitude of oscillatory variations of the load on the wheels.
Abstract