Doppler Effect and Sonic Booms: quick check

Describe a situation in your life when you might rely on the Doppler shift to help you either while driving a car or walking near traffic.

Answer it in your own words before you look.

Answer
If I am driving and I hear Doppler shift in an ambulance siren, I would be able to tell when it was getting closer and also if it has passed by. This would help me to know whether I needed to pull over and let the ambulance through.

How did it go?