Abstract: A system for sensing road irregularities from a vehicle modifies an operational system of the vehicle, such as a suspension system, according to the type and severity of the sensed irregularity. The system employs a Doppler Microwave radar sensor arranged to project radiation at a road surface ahead of the vehicle and includes means for detecting radiation reflections of which the carrier frequency is amplitude modulated according to the surface irregularities. An electronic circuit differentiates the modulated signal to produce a control signal representative of said surface condition and a controller receives said signal and modifies the operation of the vehicle system in response thereto.