Final answer:
Seek clarification on signal changes before taking action for safety. Doppler shift is noticeable in daily life through the changing pitch of sirens or engines, which can inform us about their movement and aid in safety.
Step-by-step explanation:
If you do not feel sure that you understand a bulletin covering signal changes at a certain point on your route, you should not proceed until you have clarification. It's crucial to ensure the safety of yourself and others by seeking assistance or additional information before taking action. Example of Doppler Shift in Everyday Life: In everyday life, a common example of relying on Doppler shift is when you're driving a car or walking near traffic. You might hear the change in pitch of sirens or car engines as they move towards or away from you, indicating their direction and speed. This can alert you to potential dangers and help you respond appropriately to your surroundings.