I don't believe they were ever.. MADE for 'passing' it's just an alternate use for this fuction of headlights now. Like J@tko said, where I am from also, flashing your lights is a gesture to allow someone to pull infront or go ahead of you. As for bikers, well.... there is 3 types : 1st one is : I have a bike because I don't have a car. The 2nd one is : I like japanese bikes that scream to 16000000000000000rpm for nothing when I can't ride for **** (probobly the same ones Ajp was talking about). And then finally you have historic bike riders, which are the most respectable out of the lot, you know these old-timers know how to ride a bike, but these idiots on Superbikes thinking they can get their knee down and slide a bike around like Ruben Xaus.