Not very often. I was buzzed this Saturday on a wide, empty road by a driver who then settled back into the far left lane on a 3 lane street. Either an ignorant a$$hat or the person dropped the cell phone. But it's unusual for it to happen eventhough the main part of my commute is on a pretty busy single lane in each direction road. I still don't get the drivers who will drive up the wrong side of the road to avoid me. The overkill just looks dangerous.