Abstract: The electric power consumption of a vehicle having its own power source and travelling on an unbounded path is monitored; and, when this power consumption remains substantially constant for more than a predetermined period of time, the invention sends a signal to the driver, to which he must respond with predetermined accuracy and in a predetermined period of time. Failing this, the invention gives the operator a warning display and repeats the test which, if failed repeatedly, results in the equipment giving an alarm perceptible to those outside the vehicle, by the horn and/or flashing lights. In addition, the invention can preserve a record of the driving conditions and test results and can provide coded access to operation of the vehicle to prevent unauthorized entry. The invention can also provide a test of alertness which the driver must pass before actuation of the vehicle can be initiated.

Abstract: A safety power track system for carrying light fixtures including a light source includes a generally U-shaped supporting rail, the limbs of which have inwardly bent ends. An internal insulating lining fits into the rail, and has at least a first current conductor embedded therein; a grounding member is connected to the ends of the limbs of the rail, and at least a second current conductor is mounted in, or on an externally inaccessible portion of the lining that faces inwardly of the rail. A transversely mounted, reciprocally movable push-button switch has "on" and "off" positions and is formed with an oblique groove; a presser cam is guided for movement in the groove, and at least two conductors engage the cam in the "on" position. Conductor springs are provided for making contact with the cam, and a conductor fixing screw establishes contact of the spring and the cam.