And for some reason it's a violation of municipal law in Anchorage to mount/operate a whistle or siren on/from a bicycle. Maybe because the bike cops use whistles? Oh, but bells are mandatory. Speaking of which, my bell tends to scare dogs, freeze 'em in their tracks or spook 'em out of the way. Might a legal and feasible alternative to the airhorn if you live where horns are outlawed.