The paper presents a control scheme of counter-overflow by use of double detectors to alleviate the problem of overflow at intersections with oversaturated traffic. According to the conservation principle that vehicles at the entrance and the exit of intersections are the same, the running status of vehicles at intersections with saturated traffic and the queuing rule of vehicles under traffic congestion, the paper figures out the method of determining the installation positions of the overflow identification detectors and the queue dissipate detectors. Then, information including vehicle speed, vehicle count and the occupancy rate can be used to determine whether there will be overflow while the threshold speed of vehicles will be used to determine whether the queue is shortening. According to the different status of traffic lights at intersections with overflow and its downstream intersection, two counter-overflow schemes --- intercept or evacuate are formulated based on minimum green. Finally, a VISSIM simulation study is conducted at two adjacent intersections of Anli Road in Beijing to evaluate the proposed control scheme. Results show that the scheme can mildly eliminate traffic overflow, and make the transition from the counter-overflow control phase to the timer control phase smoothly and thus prevents the drastic changes in traffic flow. The current research can provide a theoretical and methodological basis for counter-overflow traffic control at urban intersections. KEYWORDS: Traffic control; queue overflow; overflow identification; traffic simulation

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