Cars really slow down as they approach me with the helmet light. The real reasons I put the light on the helmet are 1) I like having where I look illuminated and 2) I don't need to buy multiple lights or mounts for multiple bikes and switching lights between them. I did buy a few of the rechargeable blinky tail lights to mount on each bike because they are inexpensive. Like to screw them on so they don't disappear while I'm in a store.