The real-time traffic conditon of an intersection is monitored with the help of a drone floating over the intersection. This can act as an gudiance for the police to take traffic dispersion measures timely for traffic jams or traffic incidents. In addition, computer vision algorithms are used to footage the obtained video logs, in order to identify the vehicle number and vehicle trajectories at the intersection. It solves the laborious and time-consuming problems in human-powered vehicle counting, and plays a guiding role in optimizing the phases of the traffic signals at the intersection.