Final answer:
A traffic signal that always displays a red light is a stop signal, requiring vehicles to come to a full stop. While there could be emergency situations that make running a red light seem justifiable, traffic laws typically require adherence to this rule without exceptions.
Step-by-step explanation:
A color-light signal which always displays a red light is known as a stop signal. When approaching such a traffic signal, the rule is that drivers must bring their vehicle to a complete stop. This is in contrast to a caution signal, which would usually be yellow and indicates that drivers should slow down and prepare to stop if necessary, not that they must stop immediately regardless of circumstances. In an emergency situation, such as when a pregnant woman in the car is about to give birth, some may argue that breaking the stop rule might be morally justified if doing so leads to greater overall good, such as safely reaching a hospital. However, traffic laws generally do not make exceptions for emergencies in terms of obeying a red light.