本論文主要是針對上高速公路的匝道口及交流道出口所銜接的十字路口號誌燈做探討，利用模糊控制理論設計出交通號誌的控制器，以維持高速公路車流順暢。在第二章中，我們對於匝道儀控與高速公路行車流量的關係做了分析與討論，而設計了管制進入高速公路車輛數模糊控制器，並做了效能的模擬與分析。至於交流道出口所銜接的十字路口號誌燈控制，則在第三章中提出，在此章中，我們除了考慮四個路口的變燈順序與時間外，更因時制宜的提高交流道出口號誌燈的綠燈優先順序，以預防高速公路上的匝道車輛回堵情形，最後，也對所提的控制器與傳統的定時控制器，做了電腦模擬與分析及比較。 This thesis utilizes the fuzzy control concept to design traffic light controls on the entrance ramp and on the intersection near exit ramp of highway, respectively, such that the traffic lights work well to maintain the smoothness of the traffic flow on the highway. In Chapter 2, the designed control includes fuzzy decision base (FDB) to estimate the probability of the light change and a decision function (DF) to decide the change making of the light. We only need one sensor to measure the speed and the speed change rate of the vehicles on the highway. Our simulation shows that the proposed control has a good performance. On the other hand, we know that the traffic jam on the highway is always caused from the heavy load in the exit ramp. Chapter 3 develops a fuzzy controller to decide both phase sequences and phase lengths of traffic signals adaptively according to the traffic conditions in the intersection near exit ramp. Moreover, it also guarantees the higher priority of vehicles in the exit ramp than those in the other intersection streets. Then, the traffic jam in the highway will be forbidden. Finally, we give a simulation to illustrate the proposed controller's operation and its performance.