contrailcortail-illustrationCyclists are leaving their mark. Literally. Developed by Studio Gelardi for a competition in 2008 – DESIGN21 “POWER TO THE PEDAL”,  Contrail is a tool for developing bicycle communities. As they ride, cyclists leave a faint chalk trail behind their bikes. Think sidewalk chalk for grown-ups, without the mess. The idea behind Contrail is that the biking community encourages others to join them, safety in numbers. The more cyclists, the brighter the chalk lines, warning cars to stay clear.  
A great way to brighten the drab, grayness of most city streets.


via:  doobybrain