Traffic congestion has become a serious problem in the urban districts. This is mainly due to the rapid increase in the number and the use of vehicles. Travel time, travel safety, environmental quality, and life quality are all adversely affected by traffic congestion. Many traffic control systems have been developed and installed to alleviate the problem with limited success. Traffic demands are still high and increasing. This paper is to introduce a versatile fuzzy logic traffic flow model capable of making optimal traffic predictions. This model can be used to evaluate various traffic-light timing plans.