Abstract: Presented is a radio controlled safety stop system for forklift trucks including a transmitter mounted above a doorway in a warehouse or other building in such a way that a radio signal is continuously transmitted by the transmitter when the door is closed in a pattern such that the signal strength of the radio signal at a predetermined far distance from the door is detectably weaker than the radio signal that is detectable at a predetermined near distance from the door. Mounted on the forklift truck and provided with an appropriate antenna to detect the signals being transmitted, is a radio receiver which detects the radio signal when the forklift truck moves into the far distance zone included by the relatively weak radio signal, and which then functions to activate an alarm to warn the driver that he is approaching a danger zone.