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模糊控制器的应用于1977年首次在文献中提出，其中指出对于有简单绿灯延时控制的单车道交叉口，模糊控制器比车辆感应式控制器更具优势。此后，模糊控制器有了进一步发展，关于交通信号控制的模糊逻辑方法的研究也进一步深入，该方法被陆续应用于无转向车流的双车道交叉口、无限制的单车道交叉口、多交叉口、相位顺序和相位时长控制、拥挤交叉口和路网等等，尤其在高负荷和不均衡交通流条件下表现出优于传统交通信号控制方法的特性。模糊逻辑方法可以改善自适应交通信号控制，改变自适应控制器和TMS的整个决策过程，很大程度上改善未来的交通需求管理方法，然而这类交通信号控制和交通需求管理方法的实际应用并不多见。在诸如沙特阿拉伯这样的发展中国家，学者应根据本国的特有情况研究基于模糊逻辑的交通信号控制与TMS的发展潜力，从而减少拥挤导致的各种损失。

Review of the Fuzzy Logic Based Approach in Traffic Signal Control: Prospects in Saudi Arabia

The first implementation of fuzzy logic controller in the literature appeared in 1977, which shows better performance compared to vehicle actuated controller for a very simplified intersection having two one-way streets based on a simple green time extension principle. After that, further development is taking place by adopting fuzzy logic based traffic signal control for two-way single intersection without turning vehicles, single intersection with all possible movements, multiple intersections, phase sequence and time determination, congested intersection and network, etc. Research in fuzzy logic based traffic signal control is getting inspired by the results which indicate better performance compared to traditional traffic signal controls, specifically during heavy and uneven traffic volume conditions. It can be expected that the fuzzy logic approach will not only contribute in the advancement of adaptive traffic signal control but will also contribute significantly in the future approach of transportation management system (TMS) by improving the performance of the adaptive controller and the overall decision making process of the TMS. However, there are only a few examples of this kind of traffic signal control or TMS in real life. Researchers in rapidly developing countries like Saudi Arabia should investigate the potential of the fuzzy logic based traffic signal control or TMS under the unique local conditions to curb the loss incurred due to congestion.