A ghost bike is a bicycle memorial, painted entirely white. It usually points to a location where a cyclist was killed in a collision with a motor vehicle. The memorial bikes are meant to raise awareness of safety issues faced by cyclists and honor those who have lost their lives.
As a cyclist, I'd also like to sensitize about our vulnerability against vehicles weighing tons. I took this photo, deliberately framing a "car" road sign to emphasize its meaning. The white snow complements the white "ghost" bicycle.