Any commuter, whether driver or cyclist, knows the pain of getting held up at red light after red light on the way to or from work, so the Spring Lab Flo sensors are designed to help alleviate that issue for cyclists. Placed at intervals about 120 meters from the nearest traffic light, the sensors give cyclists a heads up about how to continue if they want to catch the light while it's green.
The sensors measure each oncoming cyclist, and they then do a quick calculation based on the timing of the light. Spring Lab Flos are connected to the city infrastructure (and thus know the traffic light sequences). If cyclist's speed isn't enough to reach the green in time, the sensor will tell them to speed up. And if they're moving too fast and bound to hit a red, they're told to slow down.