weird.. we do not have this where I live near vancouver canada... or at least, I've never heard that sound for a reversing truck.  I wonder why that sound hasn't crossed over here.,(reply>), hope it doesn't become standard because white noise is inaudible, i wouldn't notice it period. plus it is too similar to airbrakes, so if you heard that and a truck was backing up you could confuse that with the air brakes malfunctioning.,(reply>), +Katherine S Different standards across different countries and different companies, also depends on the setting it's being used in.  In reality you're probably looking at 10 years or so before it becomes common across the world as it starts to be demanded by different OH&amp;S organisations and insurance companies.,(reply>), as far as i know, there are no such trucks in the u.s.either