This article describes a machine-vision based alerting system which detects and tracks headlamps of cars in night traffic.
Every year in the United States several people whose job takes them to the sides of roads, are injured or killed by roadside collisions. This could be avoided if a warning signal could be sent to them. The system described in this article automatically computes a "normal traffic" region in the image. Unusual trajectories of cars are detected when the images of their headlamps move out of that region. The system promptly sends a warning signal once a risk has been identified. The system runs on the Android smart phones, which are mounted on cars or on roadside fixtures. (publisher abstract modified)