Because ambulance lights are most commonly on (at least for half of their trip), while hazards are usually only used a handful of times in the lifetime of a normal car. Under typical operating parameters, it is exponentially more common to see emergency lights on ambulances and police vehicles than it is to see hazards turned on with cars.
Because ambulance lights are most commonly on (at least for half of their trip), while hazards are usually only used a handful of times in the lifetime of a normal car. Under typical operating parameters, it is exponentially more common to see emergency lights on ambulances and police vehicles than it is to see hazards turned on with cars.