Bell Man

When I just started my Yonghe life, I was confused about why there is always a man riding a bike and ringing a bell while a garbage car is passing by. The car can play music such as “For Elise” and “The maiden's prayer” itself, then why a bell-man is still required to inform everybody the car is coming?

I figured it out recently. The reason may be the streets and lanes are too narrow for a garbage car goes through. Thus a bell man rides his bike through those narrow lanes is required.