Final answer:
You must yield the right of way when an emergency vehicle, like an ambulance, uses its siren or flashing lights, stopping your vehicle until it passes by. Using your emergency flashers is unnecessary unless you need assistance, and you should stop regardless of which lane the vehicle is in.
Step-by-step explanation:
When an emergency vehicle, such as an ambulance, sounds its sirens or uses flashing lights, you must yield the right of way. This means you should stop moving and become stationary until the emergency vehicle has passed by. It is not correct to turn on your emergency flashers unless you are part of the incident or also need assistance, nor should you only yield if the vehicle is in your lane as emergency vehicles might need to navigate across multiple lanes. Furthermore, you should not proceed without stopping, as it could hinder the emergency response and is also against the law. In any case, you must act quickly and safely to allow the emergency vehicle to pass.
Understanding the Doppler shift in an ambulance siren can also be helpful, as it can indicate when the ambulance is getting closer or has passed by. However, it is ultimately the visible signals and the law that dictate your response in this situation.
Comparing to other situations, such as the urgency of reaching a hospital with a pregnant woman about to deliver, rules such as stopping at a red traffic light might, in rare cases, be weighed against the necessity to act for the greater good. Yet, this does not override the general requirement to yield to emergency vehicles.