Siren isn't necessary if everyone can see the flashing lights reflecting off road signs, vehicles in front and their own mirrors. Nobody bothers to move an inch over there anyway, so other than protecting pedestrians, absolutely no point other than to deafen oneself.
In China, we call it "the elderly mobility vehicle", which is actually an illegal four -wheeled electric vehicle that does not require any driver's license and procedures
My hometown's Police Department has 2 Police Packaged Harley-Davidson Motorcycle's that has these exact same color light's, I would have no idea that this motorbike was a Ambulance.
