Smart Traffic Control System
The Tai Tam Road (Dam Section) was constructed more than a century ago and is part of the thoroughfare connecting Chai Wan with Stanley. Since its width is only 5 meters, congestion problems often occur when larger vehicles, with widths of 2.5 meters, use the road. Widening the road section is not possible, as the dam has been declared as a monument. Thus, the Smart Traffic Control System (STCS) based on video analytics (VA) technology has been developed through a collaboration between Hong Kong’s Transport Department and the Chinese University of Hong Kong project team, which created a VA-based Trolley Monitoring System for the Hong Kong International Airport in an LSCM R&D project. The smart city system, the first of its kind in Hong Kong, has been deployed to cut down on delays.
The STCS has 8 sets of traffic detectors installed within 400 meters of either side of the scenic but congestion-prone road. Each traffic detector turns video content into real-time traffic data by detecting, tracking, and counting vehicles passing by. The STCS then uses data from all 8 detectors to compute vehicle queue lengths on both sides of the Dam and adjust the duration of green traffic light signals to reduce overall delays in real-time. For instance, when the system identifies a queue longer than 200 meters on one side and the other less than 200 meters, it allocates an extra 165 seconds of green signal. After the queue is cleared, the traffic lights show a red signal on both sides for 45 seconds so that all vehicles along the Dam Section can be cleared.
The smart traffic control system for Hong Kong has been commissioned since August 2018 and according to the latest figures, it is twice as effective with time saving compared to traditional traffic lights. Based on records from August 25 to the end of November 2018, the traffic queue in Tai Tam Road did not exceed 400 meters at peak hours. With a traditional traffic light, it took around 400 seconds for the drivers to queue up and pass through the dam; however, with a smart traffic light, it only took around 145 seconds.
The Smart Traffic Control System has won a Silver Medal at the 47th International Exhibition of Inventions Geneva in 2019.