Apparatus for insuring a vehicle operator's attentiveness at potentially dangerous locations along a path of travel. A signalling device is provided in advance of a potentially dangerous location, in the direction of travel of the vehicle. A vehicle carried signal responsive device responds to the signalling device when within the effective zone of the signalling device. The vehicle includes warning apparatus, for example, an alarm and a buzzer. The vehicle also includes an operator actuatable push button and a speed sensing apparatus. A control device responds to the push button and to the vehicle carried signal responsive device to operate either the buzzer or the alarm. If the operator evidences his alertness to the potentially dangerous location by actuating the push button prior to reaching the signalling device (within some constraint), the control apparatus merely sounds the buzzer when the signalling device is detected and resets itself. On the other hand, if the operator fails to actuate the push button in advance of detection of the signalling device, or, if his actuation is too far in advance of detection, then the alarm is energized and will remain energized until the vehicle is brought to a stop, or a low speed, at which point, push button actuation can cancel the alarm.