Real-time traffic analysis at night-time

This paper presents a video-based approach to traffic analysis and monitoring in night light conditions. In this kind of scenarios the headlights of the vehicles are the main features of the image taken from an urban or inter-urban traffic camera. The body of the vehicles is very low contrasted and many of the algorithms used in day-time decrease their performance. In our algorithm, we detect car headlights, and using this information, we obtain the three main magnitudes used in traffic monitoring: number of vehicles per time unit, i.e. intensity, mean speed, and occupancy. Extensive evaluations show that the system exhibits an excellent performance with real-time video sequences from cameras of the Traffic Authority of the city of Valencia, Spain.