Ghost bikes are a phenomenon from New York - a memorial to those cyclists killed on the roads of the city. At traffic blackspots all over New York, white bicycles decorated with photographs of the victims, are found. Most often appearing overnight.
The two lobby groups behind them try to find a bike close in style to that ridden by the victim. They then remove parts such as brake cables and let the air out of the tyres, to discourage thieves, and paint them in DayGlo white.
To be perfectly honest I am not sure what I think of this, though it is undoubtedly taking off. People are killed in cars every day too, some in accidents by avoiding cyclists.