Final answer:
If an emergency vehicle with flashing lights is approaching on a multi-lane one-way street, you should pull over to the right and stop. This allows the emergency vehicle to pass safely. The observed frequency of a siren due to the Doppler effect matches the actual frequency when the vehicle is approaching you.
Step-by-step explanation:
When you are driving along a multi-lane one-way street and you see an emergency vehicle with lights flashing in your rearview mirror, the proper action to take is to pull over to the right and stop. This action ensures that the emergency vehicle can pass by safely and quickly, which could be critical in a life-threatening situation. It is important to stop moving and become stationary until the emergency vehicle passes by. Making any other movements such as speeding up or maintaining your speed could put both you and the emergency responders at risk.
To answer the GRASP CHECK, the frequency of the siren that you observe will most closely match the actual frequency when the ambulance is coming toward you, due to the Doppler effect.
The concept of the Doppler shift is also useful when driving; it helps in determining when an emergency vehicle with a siren is getting closer or has passed by. This can guide a driver to know when to pull over and let the emergency vehicle through.