Black ice is one of the biggest hazards on islands roads during the winter season, and Queen Charlotte RCMP Sgt. Rob Knapton warns islanders to drive slowly and carefully if conditions are icy.Black ice is simply ice that is invisible because it's clear. It forms quickly in the right weather, usually (but not always) in the early morning or evening hours when temperatures hover around the freezing point."Drive appropriately for the conditions is my advice for drivers, all the time," Sgt. Knapton said. "When conditions are less than ideal, slow down."