This paper presents a fuzzy logic controller for an isolated signalized intersection. The controller controls the traffic light timings and phase sequence to ensure smooth flow of traffic with minimal delay. Usually fuzzy traffic controllers are optimized to maximize traffic flows/minimize traffic delays under typical traffic conditions. Consequentially, these are not the optimal traffic controllers under exceptional traffic cases such as roadblocks and road accidents. We propose a new fuzzy

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... ffic controller that can optimally control traffic flows under both normal and exceptional traffic conditions. In this system, sensors are placed strategically at incoming and outgoing links (lanes) and the controller utilize the information received from these sensors to make optimal decisions to minimize the traffic delays. A simulator is developed to evaluate the performance of traffic controllers under different conditions. Results show that the performance of the proposed traffic controller is similar to that of conventional fuzzy traffic controllers under normal traffic conditions and is better that of others under abnormal traffic conditions.