Friday Fun: Colorful Chalk Markings for Bike Paths
Contrail, a bicycle advocacy tool, uses chalk to line the path of bicycles. Photo via Bike Contrail

Contrail, a bicycle advocacy tool, a community-building device and public art project, uses chalk to line the path of bicycles to celebrate shared spaces. Photo via

Contrail, created by ULICU, a social innovation company, is a small attachment to your bicycle that dispenses non-toxic and eco-friendly chalk liquid on to the tire of your bike and leaves a temporary mark on the pavement. The project wrapped up its KickStarter funding phase in November and is now in production to be distributed to non-profit organizations. With 204 backers, the tool is best used in groups, leaving a multitude of paths and colors on shared spaces. In fact, the project’s website lists guiding bike rides and fundraisers as the best times to use Contrail.

However, the creators of the product warn supporters of local graffiti laws before using the device. “We are working with community centers and city officials in New York City to use Contrail at city-sanctioned events,” the project’s website states. “While we hope this breeds positive reception for Contrail, please be advised that graffiti laws change by municipality and users should be aware of local graffiti laws before use.”

The project’s main objective is to get more people on bicycles and create safer shared spaces. Within this, there are three smaller objectives the project hopes to accomplish. The first one is to celebrate the growing bicycle community. Through a partnership with “Times Up!“, a New York City-based environmental nonprofit, Contrail hopes to organize neighborhood-exploration group bike rides.

The creators of the project also aim to lend the visual aesthetic of Contrail to fundraising efforts for various causes. According to the project’s KickStarter page, using Contrail for such highly visible fundraising rides would leave an even stronger impression and message.

And lastly, the project hopes to lend its lasting marks to establish safe riding routes for young adults to bicycle to school. In a partnership with Biddeford Maine Community Bicycle Center and other local businesses to fund extra signage and crossing guards, Contrail will ensure safe routes. “To celebrate and illustrate the new paths, over a designated week students will ride from school to their neighborhoods and back using donated Contrails,” says the project’s KickStarter page. “The result will be a path of lines that converge and grow brighter as they approach the school.”

To follow Contrail, you can visit their website at

Chalk markings left behind by Contrail. Photo via

Chalk markings left behind by Contrail. Photo via

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