Invented by ULICU, now being developed at Tomorrow Lab

Contrail is a public art project that celebrates shared spaces, helps make bicycling safer and more fun.

Contrail attaches to your bicycles and, as you ride, the device leaves a colorful trail behind you.

Contrail uses washable, non-toxic chalking fluid made from eco-friendly pigments. Like a jet's contrail, the lines on the road will fade with time and rain.