Abstract: The invention relates to a radar device having a housing that includes: a microwave motion detection module (3) generating a Doppler signal, a signal processor (5) for calculating a speed from said Doppler signal, processing means (1) for switching the module and the signal processor from a detection mode to a speed-measuring mode and vice versa, a wireless interface (8) for transmitting said speed to a remote device, and a self-contained power supply (9) for powering the device.