In London, a crowdsourced effort to track unsafe streets for bike commuters is giving cyclist advocates and the local government new insight into where the most dangerous spots to ride are.

Last week, 500 cyclists begin riding around the city with a button on their handlebars that they are instructed to push when they feel unsafe, nervous or frustrated on their daily trips.

When a cyclist hits the button, a message is relayed to an app on the cyclist’s smartphone, which logs the dangerous location on a public map, and e-mails the mayor, reminding him of his promise to protect those on bikes.

“Cycling could be even more the choice of people in London. But people are holding back because they feel that it is an unsafe environment,” said Fredrik Carling, the chief executive of Hovding, which provided the buttons at no charge. “We’re lagging behind on infrastructure and culture and experience in dealing with all these cyclists.”

The Swedish company is best known for its creative helmet for cyclists, which is essentially an airbag that wraps around the neck and inflates in the event of a collision. Hovding has sold 25,000 of them since 2012

This initiative from Hövding Sverige features 11-year-old Merlin pushing for more bike safety in London. (Hövding Sverige)

Hovding distributed the buttons with the help of the London Cyclist Campaign, which received 750 requests for the 500 buttons.

“It’s definitely captured people’s imaginations,” said Amy Summers, an activism coordinator at the London Cyclist Campaign, which has heard from officials in cities around the world who are interested in similar campaigns. “I think it can be a really effective tool used by other cities to make cycling safer and improve their streets.”

In about a week, the crowdsourced map already has 1,000 locations cited for unsafe conditions. Summers said there are hardly any reports of unsafe circumstances along roads with protected bike lanes, which include barriers to physically separate cyclists from vehicles.

Hovding does not plan to charge for the buttons, and is interested in distributing them in other cities, provided it can find a reputable partner with ties in the local cycling community to distribute the buttons.

“If we believe that cycling is one of the main transportation modes of the future, and a lot of people think that is,” Carling said, “we need to make traffic safe not only for people in cars, but people that walk on sidewalks and also for cyclists.”