Tesco delivery trucks have them here in Ireland; it's pretty good stuff. Still quite loud/noticeable when you're up close, while at the same time not being completely obnoxious to everyone in a kilometre radius.
Looking at their website it mentions several patents, so perhaps that's one reason it's not more widely used.
Good lord, I've gone a long time without knowing what that was all about. First time I heard it I assumed the lorry had a broken reversing beep speaker or something!
Tesco delivery trucks have them here in Ireland; it's pretty good stuff. Still quite loud/noticeable when you're up close, while at the same time not being completely obnoxious to everyone in a kilometre radius.
Looking at their website it mentions several patents, so perhaps that's one reason it's not more widely used.