The term "stoplight" meaning a traffic signal is semáforo. The word for a brake light on a car is luz de freno.
If there is a light labeled right turn signal and it is red, you can not legally turn.
A signal light that is not working.
Stop light is another name for a traffic signal.
On a vertical display traffic signal the green light is on the bottom. On a horizontal display traffic signal it is to the right, but may depend on that state (or municipality's) practice.
Railway signal
The impact of a traffic lights on a highway or street is to drastically reduce the maximum traffic carrying capacity of that road. During rush hour traffic is always backed up when a light turns green, because more vehicles are arriving at the stoplight than can get through it.
The yellow light on a traffic signal means that the light is about to turn red. It serves as a warning for drivers to slow down and prepare to stop.
A yellow light on a traffic signal means to slow down and prepare to stop before the light turns red. It serves as a warning that the light is about to change.
A solid yellow light on a traffic signal means to slow down and prepare to stop before the light turns red. It indicates that the light is about to change to red.
A steady yellow signal light at a traffic intersection means that the light is about to turn red, and drivers should prepare to stop safely before the intersection.
A traffic light is a light source as it emits light to signal drivers when to stop, slow down, or go.