Not so long ago, only diehard cyclists rode in London. But over the last decade, as bike lanes spread throughout the city, the number of bike commuters has doubled. Now, more people ride than ever have in the city’s history–and there are actually so many people in bike lanes that the city is testing out a special new kind of traffic light to keep them moving.





The bike traffic signals use radar and thermal imaging to automatically sense how many cyclists happen to be waiting at a particular intersection, and then adjust the length of the light so everyone can cross. At rush hour, the light will be longer, and late at night it will be short, unless a midnight bike party happens by.





“If there was a sudden spurt at a particular time it could cater for them,” says Thomas Canning from Transport for London, the city agency that is testing out the new technology. The city already has similar technology to help crowds of pedestrians safely cross the road.

If the trials go well, London will start installing the new lights throughout the city, as part of a $6 billion plan to modernize centuries-old streets. The lights will mostly go on separated bike paths, but the same technology could also potentially help at regular intersections–where people on bikes can be at risk when lights turn yellow and cars can get through, but cyclists don’t have quite enough time.