Accident Scenes
Activation of four-way flashers and internal warning lights takes place as vehicles approach within 400 feet of an accident scene, where a police cruiser is in attendance and its transmitter is beaming out a warning signal to all oncoming traffic. A small warning light on each vehicle dashboard will flash "Police/Emergency" until the vehicle has passed and is well clear of the accident scene.
 
Road Conditions
P-CEL transmitter will be connected to a series of electronic sensors embedded in the road surface at critical points such as bridge decks where black ice is a recurring problem. When ice is detected, the system will activate the four-way flashers and internal warning lights on all approaching vehicles, giving drivers a chance to slow down and proceed with caution. In areas notorious for unexpected fog and other visibility hazards, stationary photo-electric cells connected to P-CEL transmitters could caution traffic whenever visibility is reduced below a safe limit. In avalanche areas transmitters could signal the presence of obstructions on the roadway. Four-way flashers would engage and internal dash lights would flash "Road Hazard" until the danger is past.
 

Level Railway Crossing Signal
When a train is nearing a level crossing, it automatically activates the four-way flashers of all approaching vehicles. This is especially beneficial in times of poor visibility, when the vehicle's flashers and internal warning lights alert the driver to the danger, even before the crossing comes into view. The dashboard hazard light will flash "Train" until the danger is past. The signal system includes a set of strobe lights and a motion detector which keeps the signal functioning until the train has departed the crossing.
 
School Bus Loading or Unloading
Red warning lights on school bus are on the same electrical circuit as a P-CEL transmitter so that both signals work in unison. Vehicles approaching within 400 feet will automatically have their four-way flashers and dashboard warning lights activated, indicating "School Bus" to each driver. When the school bus signals are shut off, the P-CEL unit sends out a Reset signal, immediately returning all affected vehicles to normal operating status
 
Emergency Vehicles
Ambulances, police cruisers and fire department vehicles, when they turn on their dome lights and sirens, will automatically send out a P-CEL signal activating the four-way flashers on all vehicles within 400 feet. Drivers will see their internal warning lights flash "Police/Emergency" until the danger is past. This will give motorists early warning of an emergency vehicle attempting to make its way through traffic. Drivers too often do not hear or see an emergency vehicle until it is too late, usually because their windows are closed, the radio is on or they are otherwise distracted. Flashing lights will get their attention and identify the nature of the hazard.