Final answer:
When at a red traffic light that changes to green, you must scan the intersection for safety before proceeding. Traffic signals are in place to manage both vehicle speeds and pedestrian safety. In emergencies, decisions may vary, but generally, rules should be upheld for the safety of all road users.
Step-by-step explanation:
When you're stopped at a red traffic light and it changes to green, it's crucial to scan the intersection before proceeding. First, verify that all vehicles have stopped and that it's safe to go ahead. In some situations, such as the one where a pregnant woman is about to deliver in your vehicle at 4 am, moral judgments and utility considerations may affect decision-making regarding traffic laws. However, under normal circumstances, traffic rules must be followed to ensure safety. You should also observe pedestrian movements to ensure that they are not at risk when you begin moving through the intersection. Be aware of your surroundings, including oncoming traffic that may not respect the signal, the speed limit, and the presence of pedestrians, to navigate roadways safely.
The inclusion of traffic signals is principally for maintaining road safety. They ensure that drivers adhere to the speed limit, enhancing pedestrian safety, and allowing for the orderly flow of traffic. Always be prepared to stop if the situation requires, even if the light is green, prioritizing the safety of all road users. Lastly, when thinking about situations such as relying on the Doppler shift, remember this is more relevant for understanding the speed of a car as it approaches or recedes from you rather than during the decision-making process at a traffic light.