Lights.com—Warning Lights
Warning lights are used in traffic to encourage motorists to drive cautiously. They warn drivers that they are approaching dangerous roads, or that at any time the driving situation may change. Warning lights are also used on buses and other vehicles that stop often to warn followers of their intentions.
Warning Lights Mean Drivers Should Proceed with Caution
In traffic, amber lights are used to warn drivers. These lights mean to drive slowly because conditions may soon change. A flashing amber light at an intersection could be to advise the driver of possible pedestrians or a dangerous intersection. Warning lights are also placed outside of fire stations to warn drivers to be prepared to pull over to make way for a fire truck. Drivers do not need to stop at an amber flashing light, but they should be prepared to stop quickly or suddenly change course.
School buses employ warning lights to warn followers that they will soon be coming to a complete stop. The flashing yellow lights are engaged right before flashing red lights that require drivers on both sides of the street to come to a complete stop until the red lights go off. Many states issue citations with large fines for those who fail to adhere to these signals.
Other delivery vehicles, such as post office vans and trucks, may use warning lights. These lights indicate to those following that they should be prepared to stop often. The lights flash, and can be red, orange or yellow. Some vehicles use built-in lights. Vehicles that are not federally regulated may use after-market lights to warn drivers of their sudden stops.